Lumbar Intervertebral Fusion - Factors Associated
LUMBAR INTERVERTEBRAL FUSION - FACTORS ASSOCIATED
WITH THE SUCCESS OF SURGERY
BY
PETER C. WING
M.B., Ch.B., University of Edinburgh, Scotland, 1966.
A THESIS SUBMITTED IN PARTIAL FULFILMENT OF
THE REQUIREMENTS FOR THE DEGREE OF
MASTER OF SCIENCE
in the Department
of
SURGERY
We accept this thesis as conforming to the required standard.
THE UNIVERSITY OF BRITISH COLUMBIA
December, 1972 In presenting this thesis in partial fulfilment of the requirements for
an advanced degree at the University of British Columbia, I agree that
the Library shall make it freely available for reference and study.
I further agree that permission for extensive copying of this thesis
for scholarly purposes may be granted by the Head of my Department or by his representatives. It is understood that copying or publication
of this thesis for financial gain shall not be allowed without my written permission.
Department of Surgery
The University of British Columbia Vancouver 8, Canada
Date December 1972. i.
ABSTRACT
After the performance of a pilot study of 28 W.W. II veterans who had all had lumbar intervertebral fusion at least two years pre• viously, an in-depth retrospective evaluation was performed on one hundred (100) Workmen's Compensation Board patients, all with a similar follow-up period subsequent to lumbar intervertebral fusion.
All patient characteristics were evaluated, including historical, social, physical, radiological and psychological parameters.
A success index was derived by factor analysis of twenty (20) variables all representing various aspects of the patients current functional status. This was used as a basis to analyze the remaining data by multiple correlations. These correlations were studied and
55 highly "success"-correlated variables were selected for further
factor analysis.
This factor analysis identified eight (8) factors closely asso•
ciated with success or failure of the fusion operation. In order of
importance they were identified thus:
"Normally"-functioning lumbar spine.
Mobility of body.
Freedom from neuroticism.
High pain tolerance.
Minimum number of surgical operations.
Freedom from persistent nerve root deficit. ii.
Optimism, ambition.
General health and fitness.
These eight orthogonal (totally non-correlating) factors alone
independently accounted for approximately 80% of the variance of
"success" as determined by the statistical index. It is felt that
certain of these factors may be etiological in connection with the
low back problem and prospective work is necessary to shed further
light on this.
The methods used in patient evaluation were examined and it is
felt that certain of these measures are inadequately objective and
involve measurement of several factors at one time. For example,
measures of range of 'movement as conventionally used in orthopaedics were found to show a very high correlation with certain of the
psychological measures of abnormality. Some showed poor correlation with age which is contrary to published data on the range of motion
in different planes determined radiologically. It is suggested that
alternative methods be used which would provide greater specificity.
Increased use of quantitative radiological methods is suggested
as this provides an accurate way of comparing patients from a purely
structural viewpoint.
The psychological profile of the patient is shown to be of great
importance as twothirds of the patients showed an elevation of one or
more Minnesota Multiphasic Personality Inventory scales over a T-score
of 70; in a random population this figure would be approximately 31. iii.
It is suggested that psychological evaluation should be used at all
stages of low back pain disease to assist in management of the pa•
tient .
Pseudarthrosis was determined to exist in the presence of two
out of three radiological features:
Movement at the fusion site on bending x-rays.
Presence of a defect in the bone mass.
Persistence of the posterior apophyseal joints.
The presence of pseudarthrosis did not correlate significantly with success or failure of the operation.
It is stressed that only information obtainable in an accurate way of all patients was used in this study and this prevented the use of operative reports, from the patients time of surgery which was
frequently inaccurate and was not uniform in the information they provided. It was decided not to use symptomatic information as re• membered by the patient from before his operation as this would be
coloured by too many subsequent events and would not be matched by
comparable physical, radiological or psychometric results. Similarly,
success was not correlated with the individual surgeon as some sur•
geons were represented by too few cases and some patients would have been seen by several surgeonsaat different stages in their illness.
This evaluation of the clinical and statistical methods pro•
vides much information of use in the clinical and prospective experi• mental setting. It does not attempt to provide definitive answers iv. regarding the causes of low back pain: prospective investigation is required for this, and the nature of the required studies for this is outlined. V.
INDEX OF CONTENTS
Page
I. INTRODUCTION 1
II. HYPOTHESIS AND PURPOSE OF THE STUDY 3
III. REVIEW OF THE LITERATURE 5
IV. THE LUMBAR SPINE IN HEALTH AND DISEASE 6
Embryology and Development.... 6
Anatomy, Physiology 8
Degenerative Disease of the Intervertebral Joint 13
The Vascular Supply of the Region 15
The Nerve Supply of the Region 19
Function of the Spine 21
LUMBAR BACK PAIN DISEASE 29
The Problem of Low Back Pain 29
The Causes of Muscoloskeletal Back Pain 35
Management of Low Back Pain 46
Lumbar Intervertebral Fusion 54
SUMMARY OF LITERATURE 62
V. MATERIALS AND METHODS 63
Pilot Study 63
Main Phase 65
VI. RESULTS 72
Pilot Study 72
Main Phase 81 VI.
Page
Historical Data 81
Physical Findings 92
Evaluation of and by the Patient 106
Interpretation of the X-rays 108
Psychological Results 114
VII. PRODUCTION OF THE "SUCCESS" FACTOR 125
VIII. PERFORMANCE OF MULTIPLE CORRELATIONS AND THEIR
EVALUATION 135
The Correlation Matrix 135
Assessment of Examination Methods - What Do They
Indicate? 140
Mechanical Limitation 141
Pain Tolerance and Tenderness 142
Psychological Abnormality 143
Neurological Deficit 144
Examiner Error i 146
The Radiological Variables - What Information Do
They Provide?. 148
IX. DISCUSSION 154
Comparative Assessment of the Factors... 158
Clinical Applications 162
Prospective Studies 163
X. SUMMARY 165 Page
CONCLUSIONS 166
FIGURES 169
TABLES 173
BIBLIOGRAPHY 192
APPENDICES viii.
INDEX OF FIGURES
Page
1. The Lumbar Vertebra 169
2. Mean MMPI profiles of the thicee outcome groups,
pilot study 170
3. Radiological measurements on the lateral view 171
4. MMPI profiles by "success" quartiles 172 ix.
INDEX OF TABLES
Page
1. Biochemical Disc Changes with Age and Degeneration 173
2. Results of Discectomy 174
3. Fusion Procedures and their Originators 175
4. Comparative Results of Reported Fusion Series 176
5. Scoring Criteria for Patient Grouping, Pilot Study 177
6. Orthopedic Assessment of Psychological Parameters 178
7. Measurements of Vertebral Body Height 179
8. Measurements of Intervertebral Disc Height 180
9. Measurements of Posterior Joint Subluxation 181
10. Measurements of Retrospondylolisthesis 182
11. Measurements of Interpedicular Distance 183
12. Measurements of Sagittal Diameter of Vertebral Canal....184
13. Correlation Matrix of "Success" and 239 Variables ...185
14. Factor Matrix from "Success"-correlating Variables; Correlation of Factors Against "Succeys" 186
15. Description of the 17 "Success"-related Factors, Their Correlation with "Success" and the Variance of "Success" Accounted for 187
16. Loadings of the NASHOLD and HRUBEC Disability Index 188
17. Psychological Scores on 4 Parameters by Quartile Grouping 189
18. Correlation Matrix of Certain Orthopedic Examination Methods with the "Success" Index, Certain Psychological and Radiological Variables 190
19. Correlation Matrix of the Radiological Variables with the "Success" Index, Certain Psychological and Mechanical Variables 191 X.
ACKNOWLEDGEMENTS
* The complexity of this study has entailed the involvement, directly or indirectly, of many people. Without their assistance my work would have been impossible. I mention these particularly, to whom I wish to express my deepest thanks and appreciation for advice, practical assistance, or sustenance:
Dr. K.S. Morton and Dr. P.J. Kokan, my sponsors and project supervisors, who initiated and directed my interest.
Dr. F.P. Patterson, Professor of Orthopedics, who made possible my year's Clinical Research Fellowship, which expanded to eighteen months. Franz Wilfling, with whom I exchanged orthopedic ideas and optimism for psychological ideas and a statistical foundation. Dr. W.J. Thompson, Head of Orthopedics at Shaughnessy Hospital, for encouragement and provision, with the Department of Veterans Affairs, of facilities for conducting the study. The Workmen's Compensation Board of British Columbia and the British Columbia Medical Services Foundation, for patient selection information and generous financial support. Dr. S.S. Shim, for experienced advice and help with the prep• aration of the thesis. Mrs. D.A.R. Myers, for stout-hearted and accommodating secretarial assistance throughout the project. xi.
Sandra Hodgins, for invaluable and patient help with difficult and unfamiliar computer programs. Pauline, for companionship, intellectual and emotional motivation, and without whom I would not have embarked on the work. 1.
INTRODUCTION
Low back pain is a common affliction, with many possible causes, which can be divided into those which are orthopedic in nature, re• lated to disorder of structure or function of the musculoskeletal structures or non-orthopedic, with pain referred to the back or lower limbs from viscus, vascular or neurological structure.
Low back pain is of great social and economic importance, partic• ularly in relation to industry, and particularly in patients who reach the stage of requiring surgical intervention in the course of their disease. The problem is expensive to the patient physically, emotionally, socially and economically and to society due to medical care and time loss. It is helpful to use the concept of low back pain disease, by which we refer the syndrome of symptoms and signs originating from disease or degeneration in the low back. This will include local features of pain, stiffness and related objective signs and also distal phenomena such as pain, muscle wasting and weakness, and re• flex and sensory loss, due to radiation, in the case of pain, or interference with the innervation of the caudal part of the body. At the outset, it is accepted that low back pain may be due to many causes; for example, severe low backache may result from pyelo• nephritis, and is common in genital inflammation whether in the female 2. or male. The Leriche syndrome classically is associated with claudicant buttock and limb pain due to arterial obstruction, tabes dorsalis with shooting pain in the back and lower limbs; a peptic ulcer often pro• duces mid back pain. Differentiation of these causes may at times be difficult but is of obvious importance; it is the purpose of this paper to consider only the orthopedic causes, specifically those treated by lumbar intervertebral fusion.
Low back pain of orthopedic origin may still arise from various known pain sensitive sources, but it is also acknowledged that a given degree of pathologic change can cause a differing pain response in different individuals and the multitude of factors responsible for this has not been fully evaluated.
It is not enough, in the practice of medicine, to approach the human organism solely in terms of tissue response or objective heal• ing of the body. It is only/in terms of function that useful patient assessment is ever made, and function must be considered in all fields of human endeavour, economic, inter- and intra-personal. It is par• ticularly important in low back pain disease to consider all facets of the patient. 3.
HYPOTHESES AND PURPOSE OF THE STUDY.
It will be shown in the review of the literature that the present state of our knowledge is largely limited to known associations of back pain, with no adequate prospective study to determine the causes or risk factors of the condition. The prospective, controlled study is the only way to determine predictive factors or risk factors, which
can give a numerical figure to the increased risk of a person develop•
ing this socially and economically costly disability.
However, methods can be evaluated and much of use obtained in a problem of such enormity by considering a small, discrete group of patients with the most severe form of the disease. Namely, those whose problems have brought them to the stage of requiring the operation of
lumbar intervertebral fusion. The conclusions from this study can
then be applied both directly to the design of prospective studies
and, with suitable modifications, to the clinical evaluation of pa•
tients with the problem of low back pain.
By studying the literature and from a certain amount of clinical
experience three hypotheses were derived.
1J Continued disability following lumbar intervertebral fusion
is of multifactorial etiology.
2) Certain patient characteristics will be identified which are
likely to be specifically associated with success or failure of the 4. operation. 3) Certain variables will be identified which may prove to be of use as predictor variables in the assessment of low back pain disease.
To allow a full understanding of the problem, a 'blunderbuss' approach was selected; to enable useful application of this approach a pilot study was performed, the materials, methods and results of which are described separately from the main phase of the study. 5.
REVIEW OF THE LITERATURE
THE LUMBAR SPINE, IN HEALTH AND DISEASE
.Hnbryology and development
Anatomy, physiology
Vascular supply
Innervation
Function: biomechanics
LOW BACK PAIN DISEASE
The Problem of Low Back Pain The Management of Lew Back Pain Intervertebral Fusion 6.
THE LUMBAR SPINE IN HEALTH AND DISEASE
EMBRYOLOGY AND DEVELOPMENT
The vertebral unit is commonly regarded as consisting of two vertebrae and the intervening disc. Vertebral development has three 239 stages: blastemal, chondrogenous and osseogenous
The blastemal stage is under way in the third week of intra• uterine life at which time the notochord has forty-two to forty-four paired somites, lying on each side, which merge across the midline and envelop the notochord as the 'hypochordal bow'. By the fourth 43 239 week ' the somites have differentiated into the dermatome, myo- • tome and sclerotome. The latter continues in the formation of the vertebral column and occiput.
Thejsderotomes are separated by the fissure of von Ebner in the region of which the cells are more closely aggregated. The inter• vertebral disc is derived from these cells, two-thirds of which originate from the more caudal segment, together with the vertebral end plated and the annulus fibrosus. Although LUSCHKA and others felt that the nucleus pulposus was derived by degeneration of the
annulus fibrosus, KEYES and COMPERE as early as 1932 pointed out the notochordal origin.
Although the nucleus pulposus in the embryo lies ventral to the 7. developing vertebral body this is corrected in the osseogenous phase.
By birth the intervertebral disc has achieved its final form with dense, close-packed spiral fibres at the periphery of the annulus fibrosus, fibrocartilage closer to the nucleus which still contains notochordal cells.
At nine weeks anterior and posterior indentations appear in the cartilaginous vertebral body from periosteal vessels, followed soon 43 by vascular invasion and calcification . Ossification appears by the 24 fifteenth week . If failure of fusion pf the initial two (anterior and posterior) 43 ossific centres occurs, abnormal vertebral growth follows . Ossifi• cation is seen first on the lower dorsal and upper lumbar regions, 43 spreading rapidly upward, less rapidly down . By the twenty-fifth week ossification reaches the periphery of the body by which time the growth plate is established.
The neural arches are formed by growth from two lateral primary centres of ossification.
A further separate ossification centre develops in the costal processoof the first lumbar vertebra, normally joining the vertebral body by five to six years of age, but occasionally growing to form a lumbar rib^3. At about puberty, a ring of bone, a traction apophysis, appears and fuses to the body at completion of growth of the vertebral column. BISK states this to be eighteen to twenty years; CARPENTER feels it is twenty-two to twenty-five years. BICK emphasises that it 8. is from the insertion of the longitudinal ligaments and does not con- 24 tribute to growth: it is not a true epiphysis
The future anterior longitudinal ligament is seen as early as seven to nine weeks to be more closely attached to the cartilaginous vertebral bodies while the posterior longitudinal band is firmly attached to the disc and not associated with the posterior surface of the disc. This close relationship of the posterior longitudinal ligament with the disc is of importance when the pain pathways are considered.
ANATOMY, PHYSIOLOGY
The normal lumbar spine consists normally of five vertebrae with associated cartilaginous discs, ligaments, muscles, neural and vas•
cular structures. Occasionally six or four vertebrae may be found with varying degrees of transition at the lumbosacral level. According
to ROCHE and ROWE in a series 6f 4,200 skeletons 2.5% of the population 219 have 23 presacral vertebral segments, 92.5% have 24 and 5%, 25 A 'transitional' type of lumbosacral vertebra is found in 10% of 247 people
The lumbar vertebra is distinguished from the others by its
greater size and by the absence of costal facets on the sides of the bodies (Figure 1).
"The body is lar^, wider from side to side than before backwards, 9. and a little deeper in front than behind. The vertebral foramen is triangular in shape, larger than in the thoracic region but smaller than in the cervical region. The shape is accounted for by the shortness of the pedicles and the direction of the laminae, which pass backwards and medially. The spinous process projects almost horizontally backwards, is quadrangular, and is thickened along its posterior and inferior borders. The superior articular processes bear articular facets which face medially and backwards, and are gently concave. The posterior border of each process is marked by a rough elevation, termed the mamillary process. The inferior articular processes bear articular facets which are slightly convex and face laterally and forwards. The transverse processes are thin and elon• gated, with the exception of those of the fifth lumbar vertebra, which are strong and substantial. A small, rough elevation marks the postero-inferior aspect of the root of each transverse process and is termed the accessory process.
" The articular facets are so shaped that, while they permit flexion and extension, they prevent rotation of the lumbar 131 vertebrae." The cortical layer of the vertebral body which is very thin is pierced, particularly dorsally,by several nutrient foramina. The cranial and caudal surfaces are covered by concave bony end plates, covered with hyaline cartilage. 10.
Articulation between the vertebrae occurs anteriorly by means of the disc and posteriorly by means of the paired, synovial facet joints.
The intervertebral disc is defined as "the fibrocartilaginous complex that forms the articulation between the bodies of the ver• tebrae^^. The gross anatomy of the disc has been described by many authors^' . The ratio of disc: vertebral body height is such that the intervertebral disc height is normally more than 35% 150 of the height of the adjacent body . The ratio is higher at birth 32 and decreases in infancy, and adolescence . The disc consists of the outer, fibrous annulus fibrosus and the inner viscid fluid nucleus pulposus.
The nucleus pulposus is usually situated eccentrically, being closer to the posterior margin of the disc and demonstrates on cross - section that it is under a moderate amount of tension. Histologically
it is composed of loose collagen fibrils in a gelatinous matrix. These have no arrangement in the centre but approach the vertebral chondral plates at an angle to become embedded there. Fusiform reticulocytes
and vacuolar chondrocytes are interspersed in the matrix.
The nucleus has a high water content, maximal at birth when 88% of its volume is water, decreasing to 80% at eighteen years and 65%
at seventy-seven years^"^'"^. The disc exhibits a power of water 114 imbibition probably related to the gel structure of the nucleus 11.
A diurnal variation in its water content is thought to account for the age-related diurnal body height variation of 2% at age five 6 2 years to 0.5% at age ninety . The matrix, has thiree constituents beside the interstitial fluid - glycoproteins, acid mucopolysaccharides and non-collagenous proteins. Other sugars besides the mucopolysaccharides are present in combination with proteins to form glycoproteins, the quantity of which increases with age. The collagen itself is a glycoprotein, with higher quantities of galactose and glucose than the collagen of other tissues such as skin and tendon"^. The noncollagenous proteins, probably bound to the mucopoly• saccharides, show a change with age. Three different types of 3 protein are identifiable: one in young children, one appearing in the middle of the second decade of life and a third type after the age of fifty that then becomes a major component of the disc tis- 156 „- sue . A..C The mucopolysaccharides present are chondroitin sulfate A and C, 21 107 keratan sulfate and hyaluronic acid ' . The mucopolysaccharide 170 content is maximal at age thirty-nine to forty years which is also the age at which the highest intradisc pressure may be developed by fluid absorption experiments 39 (and the age of onset of symptoms) 128
The cells showing the greatest affinity for the sulfate ion required in synthesis of the mucopolysaccharides (by autoradiography) are the peripheral cells of the nucleus pulposus, which shows a greater meta- 12. 246 bblic turnover than the annulus . It is possible that a constant polymerisation-depolymerisation process in the disc occurs regulating 198 the fluid components of the nucleus and hence the intradisc pressure 1QD
The pH of the disc is in the range 6.8-7.4 .
The annulus fibrosus consists of a concentric series of fibrosus
lamellae. The fibres are arranged obliquely or spirally, encasing
the nucleus; the lamellae are thinner and more closely packed poste• riorly. The fibres become longer and more horizontal near the circum• ference of the disc. The traction apophysis provides the attachment for the annulus fibrosus and the associated longitudinal ligaments.
The largest external fibres penetrate the bony ring as Sharpey's fibres; the outermost fibres blend with the periosteum and longitu• dinal ligaments.
The annulus shows a small reduction of collagen content relative 198 to the 3-protein content with age . It also undergoes a reduction 212
in water content from 78% at birth to 70% at thirty years . Poly• saccharides in the annulus are chondroitin sulfate and keraton sul• fate, and NAYLOR found ssialic acid on the periphery, possibly an 198 indication of greater rigidity at that site . DAVIDSON and WOODHALL 58
found that changes in the chondroitin sulfate were age-related , while NAYLOR stated the chondroitin sulfate fraction to be virtually unchanged with aging, although he found a definite decrease in keratan
14r . 198 sulfate 13.
Electron microscopy shows the annulus to consist of collagen 107 fibrils arranged in sheets showing biaxial orientation . The nucleii of the annular cells are frequently pyknotic or absent and fine 198 collagen fibrils are present in the cytoplasm . Granular material at the end of the biconvex cells appear to be responsible for collagen production. The chondrocyte-like cells of the cartilaginous segment of the annulus have been shown by SOUTERaand TAYLOR to be metaboli- cally active while the fibroblasts of the outer one-third of the annulus show a much lower S*^ tagged sodium sulfate uptakeThe persistence of this isotope was shown by these authors to be greater in the annulus than the nucleus.
DEGENERATIVE DISEASE OF THE INTERVERTEBRAL JOINT.
The age-related changes in the disc have been described and they overlap to a great extent with the pathological changes. NAYLOR cate- 198 gorises these changes as in Table l . The structural changes re• sulting have been described by a multitude of authors'^' 118, 218, 234, 255, 280 ™ . , . ' ' ' ' . The nucleus loses its gelatinous quality, becoming fibrous and firm while the annular lamellae lose height posteriorly by arching backwards and packing together. This happens 218 by the beginning of the third decade . The nucleus becomes firm and viscous, retaining its volume initially but losing its mobility because of fibrous anchoring to the cartilaginous end plate. In the fourth decade, small peripheral clefts appear between the layers of 14.
the annulus, particularly posteriorly and posterolateral!/, which may later coalesce and form radial tears, extending to the posterior
longitudinal ligament. Softening of the annular lamellae precedes
the cleft formation. From age sixty onwards, progressive fibrous re• placement appears to occur, with gradual apposition of the vertebrae.
Posterior displacement of the nucleus may be sudden or a chronic process, usually the latter^. Complete sequestra may form with sub•
sequent invasion of part of the disc by granulation tissue. Nerve
root damage may result by impingement of nuclear material or artic•
ular facets, which gradually sublux as the disc narrows. Osteo•
arthritis of the posterior joints may supervene, possibly due to mal-
85
alignment , with the associated cartilaginous, synovial and capsular
changes; these changes follow the disc degeneration"^.
In the later stages of disc degeneration, bony outgrowths from
the margin of the vertebral body may take various configurations.
MACNAB et al described five types, suggesting causal mechanisms in• volved"'"^. Instability (abnormal mobility at an intervertebral joint) was felt to be associated with the "traction spur", arising anterior•
ly from the vertical surface of the vertebral body about 3-4 mm from
the intervertebral border and the "bubble spondylophyte", seen pos•
teriorly in the lumbar region. They found no constant relationship
of osteophyte pattern with posterior joint arthritis, however.
Although the pathological changes (simplified here) are well 15. documented, the underlying causes are controversial. In an exhaustive review of the morphological and biochemical knowledge of disc prolapse
TAYLOR and AKESON felt the field of chemical and physical interactions 255 to be largely unexplored . They suggested physical forces are par• amount in conditioning the behaviour of the fibrocartilaginous cell and in producing changes in the extracellular components; BROWN feels that mismatching of demands made on the disc and its physical capa- 36 bilities accelerate the degenerative process . NAYLOR, on the other hand, suggested that autoimmune processes might be responsible as an 198 initiating mechanism , the feasibility of which was demonstrated 27 by BOBECHKO and HIRSCH . A multifactorial mechanism can be envisaged 279
with the interplay of several f actors,7, -. Abnormal physical loading due to loss of abdominal muscle power with age or increased resting muscle tension, added to our erect posture might initiate discal damage, with release of proteinaceous-contents and autoimmune re• action . The disease process is thus outlined: the relationship it bears to pain is discussed later. THE VASCULAR SUPPLY OF THE REGION.
The paired lumbar arteries, in series with the posterior inter• costal arteries, represent persistent intersegmental somatic branches 16.
131 of the aorta in the embryo . Four or five in number, they run lat• erally and backwards on the bodies of the lumbar vertebrae, deep to the sympathetic trunks, to reach the intervals between the adjacent transverse processes. They pass behind the psoas muscle and the lumbar plexus and pass into the abdominal wall, the upper three arteries running behind the quadratus lumborum and the last usually in front.
Each gives off a dorsal ramus which passes backwards between the 78 transverse processes, an anterolateral intraosseous branch and muscular branches to the psoas.
The dorsal branch divides almost immediately into spinal and muscular branches. The divisions of the spinal branch are:
(1) A post-central branch to the vertebral arches and liga-
mentum flavum
(2) Anterior and posterior radicular branches to nerve roots,
cauda equina and meninges
(3) A dorso-medial branch supplying the posterior longitudinal
ligament and posterior aspect of the vertebral body
(4) Muscular branches^' ^
The terminology of these vessels is somewhat confusing. MACNAB and BALL performed injection studies and found the following branches:
(1) The anterior transverse artery, from the main trunk of the lumbar artery, and lying on the anterior surface of the transverse 17. process.
(2) The intertransverse artery arising at the point of division of the dorsal ramus and passing laterally in the middle layer of the lumbar fascia about midway between adjacent transverse processes.
(3) The inferior articular artery given off by the communicating artery above or the interarticular branch below. It curves around the inferolateral aspect of the joints and pierces the intermediate layer of the lumbar fascia. 778 (4) The foraminal arteries (also described by WILEY and TRUETA A 10 and AMATO and BOMBELLI ). MACNAB and DALL describe two such branches
These supply the posterior portions of the vertebral body and the structures in the neutral canal.
(5) The communicating artery passes across the posterior aspect of the transverse process from one segment to the next segment below, where it forms an anastomosis.
(6) The superior articular arteries, usually two in number, passing around the superolateral aspect of the posterior joints.
The vertebral bodies themselves are supplied by minute vessels 278 anteriorly from the segmental (lumbar) arteries . The posterior spinal branch (presumably the dorsomedial branch of FERGUSON and
EPSTEIN) divides into an ascending and descending branch anastomosing, below, and to the other side. This posterior blood supply has been shown in the rabbit to develop just before birth, although at no time does it invade the disc, which was seen to have only a blood supply 4 to its boundaries . 18.
The disc is avascular but there is disagreement over the avas- cularity of the disc during development. DE PALMA and ROTHMAN state that the disc is supplied by small vessels through the cartilaginous end plate up to the age of eight years61. SCHMORL and JUNGHANNS give evidence that a vascular supply is seen in the outer, fibrous part only during embryonic development, while no connections exist with 234 the vessels supplying the vertebral bodies . The more abundant de• velopment of vessels in the dorsolateral part of the disc is thought to account for the proneness to cleft and tear formations in this part. All vessels are completely obliterated by the fourth year of life. PARKE and SCHIFF say that the vessels from the vertebral body never actually penetrate the disc-destined material.
The venous drainage of the area, is from the large valveless 278 venous channel draining the vertebral body via the nutrient foramen to the spinal and paraspinal plexus of Batson which shows free 18 communications with pelvic, lumbar, thoracic and intracranial vessels
The importance of the supply of the spine lies in four sources:
(1) The susceptibility to metastatic infection or tumor, although there are arguments for both the arterial and venous mechanisms here.
(2) The possibility of damage to the vessels at the time of surgery with ischemia of the cauda equina or vertebrae, potential cause of discitis of nervous lesion.
(3) As a channel for the transmission of pressure changes to the 19. spinal canal - a negative pressure being present in the epidural space normally due to transmission of the intrathoracic pressure.
(4) In the possibility of bleeding at the time of surgery, which may be of sufficient quantity to require replacement or of importance in the formation of adhesion.
THE NERVE SUPPLY OF THE REGION.
The dorsal (posterior) primary rami of the spinal nerves supply a serially segmented territory, do not extend to the muscle of the limbs and are not involved in plexuses, but supply the skin and 97 "native" deep muscles of the back medial to the angles of the ribs At each lumbar level the posterior ramus splits into a medial and lat- 204 eral branch after passing through the intertransverse ligament . The lateral branch passes through the erector spinae muscles into lon- gissimus and iliocostalis, progressing to the lateral border of the latter. It pierces the posterior lamina of the lumbar fascia and those of Ll, L2 and L3 cross the iliac crest to supply the skin of 97 221 the buttock as far as the greater trochanter of the femur '
The medial branch of the posterior ramus descends posterior to the transverse process of the vertebra below lying in a groove formed by the junction of the transverse process and the superior articular process. At the inferior margin of the superior process there is a small notch through which the nerve passes, giving a small 20.
twig to the inferior part of the articular capsule. It continues in- feriorly, ramifying in the dorsal muscles and anastomosing with nerves of other levels. It lies next to the lamina and follows the inferior border of the spinous process posteriorly almost to the midline204.
PEDERSEN et al felt that pain fibres supplied the facets and surroundings tissues204 but SCHMORL and JUNGHANNS quoting the work of HIRSCH and others were less certain that pain could originate from 234 this source . JACKSON et al demonstrated several different types 130 of fibre and nerve ending in the fibrous facet capsule 204 734 The sinU3vertebral nerve, named by VON LUSCHKA in 1850 ' is felt to be the major source of supply to the periphery of the
intervertebral disc61, 204' 234. It is also known as the ramus re- currens 234 and the recurrent meningeal nerve 221 . It arises at each level from its spinal nerve irear or with the ramus communicans then returns into the spinal canal through the intervertebral foramen, often lying against the posterolateral border of the disc; it then curves ifitephalad around the base of the pedicle and proceeds towards the midline of the posterior longitudinal ligament, giving filaments to the ligament, periosteum, blood vessels of the epidural space, 204 and dura mater. It contains myelinated fibres of varying size The disc itself does not contain nervous elements although the presence of nerve endings in the outer annular layers is debated
(PARKE-SCHIFF). The hypothesis that nerve fibres may grow into the 130 ruptured dischwith granulation tissue has not been substantiated .21. However, a nerve supply closely associated with the vascular sinusoids has been seen in the cartilaginous end plates of the vertebrae in the 130 fetus and infant . Adult supraspinous and interspinous ligaments show very few nerve endings. Ligamenta flava, showing the presence of a few nerve elements in the fetus and newborn, have only a few 130 nerves in the loose areolar tissue on the surface in the adult
Pain perception from the lumbar structures is discussed further in the section 'The Problem of Low Back Pain'. FUNCTION OF THE SPINE.
It is necessary to precede a discussion of pain arid surgery of the lumbar spine with a description of its physical properties. For this purpose, a vertebral unit is considered as the intervertebral disc and contiguous parts of the vertebral bodies, together with their posterior arches; the intervertebral joint consists of the disc and facet joints, with appropriate ligaments. It will be impossible to do justice to the literature dealing with the mechanical properties of the spine - the subject has been thoroughly investigated by many workers.
The spine'as a whole can be considered as an elastic rod"^' As such, it has a critical vertical load above which it will buckle - in the unsupported spine this is about 2 kg, while if laterally supported at both ends the value is about 33 kg, approximating the 22. weight of the trunk. Stabilisation of this rod is necessary:
ASMUSSEN and KLAUSEN suggested the model of a segmented pole stabi- 13 lised by guy-wires, represented by the muscles of the trunk . The disc acts to distribute weight over a large surface of the vertebral body during bending motions and as a shock-absorber^1' 1^)1. The stiffness of the disc is greater in compression than in tension1^ and it is felt by ROLANDER that the greatest elastic efficiencycof the disc is reached in adulthood, when the nucleus has disappeared 220 as an entity . This may be related to loss of usefulness as a shock-absorber, however. The disc appears to be the strongest part of the vertebral unit - in symmetrical vertical loading, the vertebral end-plates fracture 220 before the disc will rupture . BARTELINK's figure of average yield strength of the disc of 710 lbs. was based on specimens from subjects aged saixty to eighty years, and possibly not subjected to symmetrical loading, so that disc rupture could precede vertebral damage. However, this possibly approximates the in vivo situation more closely than that of ROLANDER. The forces acting on the lumbar vertebral unit have been care• fully calculated and evaluated. BRADFORD and SPURLING calculated that a force of 1500 lbs might be exerted on the disc in the individual lifting 100 lbs; this is clearly impossible in view of the known yield strengths31. NACHEMSON and MORRIS demonstrated the intradiscal 23. pressure to be 10-15 kg/sq. cm in the lower lumbar discs in the sitting 193 position, about 30% lower when standing and 50% lower when reclining The actual load on the disc is about 82 kp when standing and 113 kp when sitting without support, lifting 20 kg with bent back and extended 191 knees increases the load by about 300% . These figures were obtained by use of a needle pressure transducer although needle puncture may cause disc rupture Within the normal limits of motion, stability of the lumbar spine is provided by the muscles acting across it, which have been studied photographically, radiographically arid electromyographically. The muscles can be divided into four groups: a) erector spinae b) superficial muscles c) paravertebral muscles (psoas major and minor, quadratus 133 lumborum) d) abdominal muscles The erector spinae has two compartments in the lumbar region - the deep, medial multifidus compartment containing the multifidi and small interspinal, rotator and medial intertransverse muscles; the lateral border does not extend lateral to the transverse processes. The lateral or sacrospinal compartment contains the common origin of 134 the longissimus and iliocostalis muscles . These muscles have been shown to have separate functions, even different functions at differ• ent levels66. The psoas and""sacrospinal" muscles were shown by 24. 133 JONSSON to be antagonistic , yet NACHEMSON demonstrated the extensor 188 189 function of the psoas in stabilisation of the spine ' , attached to the transverse processes behind the centre of motion of the verte- 49 206 bral unit ' . He demonstrated the importance of the psoas as a stabiliser, and stated that it probably is responsible for the excess load on the disc unaccounted for by the weight of the body alone. The erectores spinae muscles show varying activity, and often 80 175 act as resistors of gravity rather than initiators of motion ' This activity ceases on full flexion at which time the ligaments appear to take the load, except that even in this position coughing will produce erector spinae activity as it does in all trunk muscles. There is normally a 'silent period' between activity of abdominal and back muscles on flexion-extension, but there is an overlap in the 172 presence of low back pain . This overlapping was not found in those with fusion for TB., if the pelvis is held immobile, or in experi• mentally produced low back pain. Instability of the lumbar spine was 172 held responsible. BARTELINK suggested the role of the abdominal muscles in re- 17 lieving the load on the spine during lifting . This has been con• firmed by data showing that the force on the lumbosacral disc is about 30% less than would be present without the support of intra- cavity pressure of the trunk. in fact, the application of external abdominal pressure by an air-pressure corset causes no overall change in the intraabdominal pressure on lifting, allowing diminished 176 237 EMG activity of the abdominal muscles ' Perhaps this represents "discovery of what everyone already 159 knows" but it is valuable knowledge in the study of the patient 191 193 with low back pain, still usually ascribed to mechanical causes '
Symmetrical articular facets appear necessary for protection of the intervertebral joint by limitation of range of motion and add 75 76 253 to its overall torsional strength ' as well as contributing to both the extension and torsional stiffness of the lumbar inter• vertebral joints1^. This is partly by maintaining the axial instant centre of rotation in its normal position in the region of the pos- 49 terior part of the nucleus ; asymmetry of the articular processes leads to asymmetrical disc degeneration, but this is probably re• lated to shear force changes rather than actual changes in range of
163 axial rotation . Intact posterior elements are apparently necessary for limitation of the different planes of motion: the spinous process being important in extension, the ligamentum flavum; flexion and ex- 273 tension The pattern of degeneration is also affected by other geometric 77 variations in the lumbar spine . The development of posterolateral fissuring is seen more in discs with flattened posterior surfaces, midline ruptures in these with a rounded posterior surface. Abnormal• ity on discography on autopsy specimens is more commonly seen at the
L4-5 level in lordotic spines and L5S1 in flatter spines, although 26. the amount of lordosis was not related to age and sex. Increased in• clination of the lumbosacral joint appeared to protect it against
77 annular damage ; some authors, however, implicate increased lumbo• sacral angle as a definite cause of low back pain40. Bending x-rays show less mobility at these levels in those with low back pain166 related primarily to age of subject and recent onset of symptoms, al• though several authors have suggested it is of structural etiology.
HIRSCH and LEWIN found evidence of osteoarthritis of the synovial joints at the lumbosacral level when the range of motion was de- 122 creased, although disc degeneration did not affect facet excursion
The strength of the anterior and posterior longitudinal liga• ments is reduced in degeneration260.
The normal mobility of the lumbar spine, however, is sometimes not accurately documented40. CLAYSON et al found the mean range of motion in the sagittal plane in the lumbar spinesof normal young women to vary from 12.6 degrees at the Ll-2 level to 18,7 degrees 45 at the L5S1 level; ALLBROOK found the motion to be greatest at the
L4-5 level (in a group predominantly consisting of Negro males).
TROUP, HOOD, and CHAPMAN used two methods to assess overall sagittal mobility of the lumbar spine in young males and females, their sur• face marker measurement showing a high degree of correlation with 2 63 radiographic techniques. The overall range of motion for a large series of young males and females was 80 degrees and 81 degrees respectively; the males showed a negative correlation with age, 27. unlike the females (within a narrow age range). This figure was a little less than CLAYSON et al's 92 degrees. TROUP and his colleagues mentioned that individual variance from day to day or even minute to minute is considerable; they also demonstrated a correlation between lumbar sagittal mobility and femur/trunk angle, of unknown signif• icance. LINDBLOM, in a myelographic study of 449 patients, found disc herniation to be more common at the L5S1 level in females than males and moie common at the L4-5 level in males than females^? Although he related degeneration patterns to direction and degree of spinal cur• vature, it may be that his figures reveal the effects of differential motion at these levels in the two sexes. THOMAS and RAU felt flattening of the lumbar lordosis to be a protective feature in low back pain, 257 produced by relaxation of the deep short extensor muscles . Axial rotation between Ll and L5 has a maximum value of about 10 degrees 99 overall , while the lumbosacral joint shows about 6 degrees of 163 rotation , the latter always being associated with flexion of L5 on SI. High torque values are likely to be associated with sudden twisting motions of the trunk in the axial direction: investigation into these continues1''". MOLL and WRIGHT, in a study correlating a clinical method of assessing motion with radiographic motion, found that mean mobility increased initially from the fifteen to twenty-fourdecade to the twenty-five to thirty-four year decade, with later progressive 28.
decrease up to 50%. Mobility in the male was found to be greater
than in the female, except on lateral flexion. (Axial rotation was excluded from this study.)
Determination of the instant centre of motion or centroid may soon find greater clinical application. It has been shown to be 206 well-localized on flexion/extension in the normal subject, lying within a discrete zone for each level but likely to be more widely
scattered in cases of intervertebral joint pathology. This normally allows the facets to slide over each other but in degeneration forces 85 them together . Thus it can be seen how biomechanical considerations are likely to be of clinical usefulness, though they have yet to be correlated with the clinical presence of low back pain - for example, the differences in abdominal and back muscle strength in those with low back pain and those without are minimal and limited to certain narrowly defined subgroups according to NACHEMSON and LINDH, con• trary to the hypotheses of previous writers quoted by them. The application of biomechanical methods to the operation of spinal fusion will be discussed in that section. 29
THE PROBLEM OF LOW BACK PAIN
"Backache may be a result of a frustrated, aggressive masculine drive or a substituted sensuous experience backache can and does at times represent a shift of sexual sensuousness to the back in the form of pain. We have been able to demonstrate clinically that with therapy when the focus of sensuous experience can be moved out of the back to where it belongs, in the pelvis, the backache disappears'^^.
Fortunately, our knowledge of the problem of low back pain in industry is greater than the above quotation would suggest, although it is from an article in 1967 entitled, "Industrial Backache". How• ever, the limitations of our knowledge are also fairly clear. Because the greatest socioeconomic impact of low back pain is in the industrial population, with consequences costly both to the workman and his employer, it is here that the problem has been most studied, even by special epidemiological teams such as the Industrial Survey Unit (LS.U.) of the Medical Research Council of Great Britain. Figures giving an idea of the magnitude of the problem may be ex• pressed as prevalence (the number of cases of the disease existing for a given area or at a given time) or incidence (the number of cases arising for a given number at risk in a particular time). Some series are not strictly comparable partly because these two different 30. figures are used and partly as some studies are based on symptomatic findings and others are based on radiological studies which are per• haps less important from the patient's and physician's standpoint.
CAILLIET has said that the low back syndrome affects 801 of 40 members of the human race . HULT found that of 1200 males aged 25 to 59 years in varying occupations occasional low back pain was pres• ent in 60%128, while HIRSCH, JONSSON and LEWIN found that 50% of the population of 692 females aged 15 to 71 years had occasional back pain increasing from 18% in the junior groups to almost 70% by age 121 45 to 54, with no increase beyond this age . HODGKIN in a study considering four different general practices in England found the yearly rate of reported backache per 1000 males to be 78.4 in three 123 urban practices and 20 in one rural practice , but it still should be remembered that many patients have been shown to treat themselves 7 rather than consult their medical practitioner . Figures from the I.S.U. showed that of 237 men classified as having 'disc disease' 48% treated themselves and did not report their difficulty to their gen• eral practitioner. The urban figures for females were slightly higher. This suggests that urban conditions tend to increase the complaint of backache but compensation is not a major motive as comparatively few 7 of the women were eligible for 'sick pay' . BENN and WOOD have pointed out the difficulty according to the International Classification of Disease in obtaining reliable figures 31.
20 for disability rates . This is because of the vague nature of the terminology involved. They found that in England "lumbago" or "pain in the back" led to a mean duration of 19 to 21 days off work for males in 1969. Radiation indicated by "sciatica", led to 36 days ab• sence and "displacement of the disc" to 53 days. It was impossible to similarly evaluate backache contained within the category of 20 "osteoarthritis" . Difficulty is also experienced in relating low back symptoms to disc degeneration. LAWRENCE, in a study of 713 males and 809 females aged 35 and over, found that 11% of the males and 19% 152 of the females had back-hip-sciatica pain at the time of the survey In addition 40% of the males and 33% of the females gave a history of pain in the past only. The pain was most commonly localised in the low back radiating in a third of the cases to the hip or the leg. It was episodic in 57%, occurred as a single attack in 29% and was chronic in 14%. HULT estimated that in Sweden approximately 2 million working 128 days are lost yearly by men because of back trouble . Other Swedish figures show spinal disorders account for 7.3-20% of all days lost from work due to illness, second only to upper respiratory infections 126 as a cause of time loss and in one series to psychiatric disorders ROWE, in a study from Kodak also found that low back disability was the top item in compensation patients and ranked second only to 224 upper respiratory infections in payment of sick benefits . In a ten- year-period, 35% of the male sedentary workers and 47% of the male 32. heavy handlers made visits to the medical department for low back pain. The time loss due to back pain in the entire division was four hours per man per year. Seventy per cent of the patients were in their thirties and forties and only 15% could relate low back pain to trauma, while another 20% could make a possible connection to some unaccustomed activity. Eighty-five per cent of the early attacks consisted of acute, non-specific low back pain and bore none of the clinical characteristics to allow discogenic diagnosis. STEINER, medical director of General Motors, found at one plant with 5,124 employees that 3,299 visited the medical department during 1967 at 250 least once for some complaint . Twenty-two per cent of these were for back complaints. The compensation aspect is of importance. MCGILL stated that workers off work with back complaints for more than six months found 182 only a 50% possibility of ever returning to work . Over a year this dropped to 25%, and over two years almost nil. He mentioned that in Washington State the average claim costs more than other forms of claims, constituting 5% of the total number of claims but 24% of the total days lost. GURDJIAN reported that in Michigan in 1966 the back accounted for 9400 of 44,000 cases of disability, the major single area of the body involved1^. He stated that figures from other states were reportedly comparable. The experience in British Columbia is that the Workmen's Compensation Board processes about 30,000 claims annual- 169 ly, and of these 6000 are back cases . In 1971 4469 were formally 33. admitted to the Workmen's Compensation Board Outpatients Clinic in 169 Vancouver; 35% of these had back injuries In the I.S.U. studies 46% of those with "disc disease" had had 7 at least one spell of absence lasting three weeks . The overall sick• ness absence rate for these patients was 143 weeks per 100 men per year. It is estimated that of the cases seen at the medical department of CP. Air in Vancouver approximately 3-5% are back related com- plaint. -+ s11 3 BOND reported that 2% of alleemployees have a compensable back 28 injury each year; many are recurrent in the same person . Back in• juries were also the subject of a study by SCHEIN from the New York Fire Department. In the period under study there were 1,687 service- connected injuries from a force of 11,000 men. Spinal injuries com• prised 12.5% of the total and 19.51 of significant injuries with four- 232 fifths of these being related to the lumbosacral region KOSIAK, AURELIUS and HARTFIEL found that in the 3M plant at St. Paul claims for back injuries constituted about 20% of all compensation 146 147 claims, averaging (up to 1960) 20.16 days per l©ist-time injury ' TROUP et al found that in Britain back injuries accounted for about
20 million person-days in time loss and JL87.5 million in economic cost annually ; however, the overall monetary costs are difficult to evaluate, in the case of a compensable patient with medical costs, 34.
time los§ benefits and loss of trained manpower and especially in the
chronic absenteeism of the chronic low back pain sufferer. The esti• mated annual cost to Blue Shield, Blue Cross and the Workmen's Com•
pensation Board of medical care alone for neckache and backache based
on the year 1967 in the State of Michigan was estimated by HAYES to 11? ?Rd be $53,000.00 . WILSON estimated that non-skeletal back injuries had cost nearly 25 million dollars in New York State in one year. In• flation may have added to these costs. The cost to insurance companies of the first back operation of any patient is estimated to be approx- 82 imately $18,000 . Approximate figures for Canadian Pacific Air show 113 $2,300,000 lost because of sick leaves in 1971 ; it is not possible to say what might be a realistic estimate for back-related complaints. Other intangible losses are inestimable, such as decrease in produc- tivityyby reduction in efficiency of the working team, a relatively
more1 important factor in the case of the skilled worker. There is a remarkable lack of figures on job instability related to back pain but ANDERSON, DUTHIE and MOODY found that in miners, disc disease was the rheumatic complaint most likely to cause a man 9 to change his job-. Effects on home life, social activity, sexual activity^, spouses and children cannot be quantitated; the emphasis on the industrial aspect is because it is the easiest to study and probably will be the most sensitive index of success of any preventive program. 35.
THE CAUSES OF MUSCULOSKELETAL BACK PAIN
SEX: The differences between male and female have already been described; incidence of symptoms seems to be approximately equal
in the two groups.
ETHNIC: BREMNER, LAWRENCE and MIALL found the same prevalence 33
of lumbar disc disease in Jamaicans arid Caucasians . FAHRNI and
TRUEMAN felt that although the hypertrophic changes on x-ray were
much the same in a primitive population in West Central India as in reported Caucasian populations, disc narrowing was found to be slight- 73 ly less common . No symptomatic comparison was made. GOFTON, LAWRENCE, BENNETT affd BURCH demonstrated a high prevalence of ankylosing spondy- 91
litis manifested as sacroiliitis in members of the Haida Indians
This was also seen in first degree male relatives of patients with
ankylosing spondylitis. BERRY described genetically determined disc
lesions in the pintail mouse (a mutation)' and suggested a similar 22 factor might be operative in humans
CONGENITAL AND OTHER ANOMALIES OF STRUCTURE:
There is some controversy regarding the role played by
lumbar spine anomalies: WILTSE comments on the lack of experimental
evidence for the discussion on the effect of the common anomalies of
the lumbar spine upon low back pain in his summary of the available 288 material, and infers a prospective study is required . He considers 36. the more common anomalies.
Defect of the pars intera'Tticularis. A person with pars defects 128 1^6 28Q is about 25% more likely to have back pain than one without ' '
It is also felt that disc degeneration occurs more often in the presence of this defect, whether it is unilateral or bilateral.
Tropism. Asymmetry of the posterior joints is felt particularly by FARFAN and his colleagues to be associated with increased wear of 75 76 77 the disc arid low back pain ' ' , due to inadequacy of their stabilising effect. Scoliosis. This does not cause an increase in the incidence of 47 126 128 low back pain ' ' , although there may be increased disc de• generation at the apex of the curve. Increased lumbar lordosis. Epidemiologically, this is not felt 126 128 247 to increase the incidence of low back pain ' ' , although 77 disc degeneration may be enhanced at specific levels Lumbosacral tilt. There is no evidence for the increased in- 280 cidence of low back pain claimed by some ; a tilt shown to be due to one short leg (if not excessively short) has been shown not to be 4Z 1 U 1 • 126> 128 a cause of low back pain ' 247 Spina bifida. SPLITHOFF rejected this as a cause of low back pain , while FULLENLOVE and WILLIAMS showed it to be more common in their 87 asymptomatic group but occasionally spina bifida occulta of the first sacral vertebra, associated with a long, hook-like-L5 spinous 37. process may cause low back pain and require surgical treatment*^.
Transitional vertebrae.. It is probable that the presence of an abnormal number of lumbar vertebrae or a transitional lumbosacral vertebra is not associated with increased low back pain^3^' ^'' but specific features associated with it, such as involvement of one transverse process in the sacroiliac articulation probably can be
. j. ,280 painful Spinal stenosis.. This is partially developmental, partially 132 231 266 acquired ' ' . Implicated in certaiiL-cases of low back pain, normal data regarding sagittal dimensions of the spinal canal have only recently been published11^. In spite of conflicting evidence, strict pre-employment exclusion screening by x-ray is held by some to be of value. SBHEIN stated that any of the following conditions would lead to rejection of candidates for employment in the New York City Fire Department: disc degeneration, failure of fusion of the posterior elements, unilateral transitional lumbosacral vertebrae, spondylolisthesis, old compression fracture, 232 and apophyseal anomaly, severe scoliosis and osteoarthrosis . His rejection rate must be at least that of MCGILL, who felt that reduced costs from back illness in a large industrial company justified a 10% 182 rejection rate . Rejection rates of 25% or more have been suggest- ed ' . Other authors, however, are less enthusiastic about pre- 1 OO 1 JA employment screenings ' . LA ROCCA and MACNAB found that no 38. developmental, degenerative change or combination of these had pre• dictive value when applied to the individual1^0. Most figures indi• cating that these anomalies are significant are retrospective, un• controlled, and part of an overall program for low back pain disease prophylaxis and care146, so that there is no way of determining which 264 health care measures were the critical ones . Prospective, con• trolled trials are essential, which will likely be indtastrially based264' 290. DEGENERATIVE: The relation of incidence of back symptoms to age leave little doubt that degeneration of the disc is important as a cause. There is a peak age of onset of symptoms, felt by BROWN to be due to mismatching of the physical demands made on the disc and its physical 36 152 strength at this age, shown to be the 4th-5th decades of life ' NACHEMSON and MORRIS have stated the opinion that "sufficient evidence is now available, although most of it indirect, to justify the opinion that most low-back pain and sciatica (is) caused by changes in the lower lumbar discs*^3. This receives support from the 119 120 pain studies performed by HIRSCH ' . LAWRENCE showed a relation• ship between lumbar disc degeneration and back-hip-sciatic pain, significant for all radiological grades of disc degeneration in males 152 but only for moderate or severe disease in females . He found disc degeneration to be a more common cause of such pain than disc prolapse, osteoarthritis, rheumatoid arthritis or ankylosing spondylitis, and 39. felt that symptoms might arise from the ligaments, because of the pain patterns.
Frank disc prolapse has been accepted as a cause of low back and 171 sciatic pain since the initial report of MIXTER and BARR , even though the mechanism of pain production is not completely clear. Most likely inflammation is responsible for part of the pain as pain is not a feature of nerve entrapments, while steroids will suppress the 198 pain of disc protrusion even if given systemically The majority of patients with low back pain are probably not 64 suffering from nuclear herniation ; MACNAB has described five types 184 of pathogenesis of symptoms in disc degeneration : Type I Segmental instability (repetitive ligamentous strain). Type II Segmental hyperextension (pain due to chronic strain of the posterior joints). Type III Chronic posterior joint subluxation associated with disc narrowing. Root compression may complicate this. Type IV Posterior joint arthritis - usually secondary to disc degeneration. Type V Root irritation - may result from disc herniation, spinal stenosis; or foraminal entrapment, pedicular kinking, or extraforaminal engulfment of the nerve root. Undoubtedly, then, degeneration of the intervertebral joint is of central importance in painpproduction, but it is not certain at what stage and in what individuals it will present. There is a lower 40.
overall correlation of back-hip-sciatic pain with the lesser degrees 152 of radiological change , further, a normal radiograph is compatible 118 120 with considerable degenerative change ' . This variation may be 63 229 267 accounted for as superadded muscular pain ' ' or differences . 267, 293 in individual pain response As RABINOVITCH says: "Much ink has flowed on the subject of intervertebral discs. Those who float forth on the sea of literature on which disc problems still float should be. guided by the explorers...
The explorers have demonstrated the Virchovian importance of the concept of disc degeneration, more information is required regarding its link with pain and functional impairment.
84 METABOLIC: Osteomalacia is probably a cause of backache , but is very rare in comparison with the high incidence of back pain. Osteoporosis is much more common and has been demonstrated to be age- related. However, partly because of this relationship with age, it has so far been impossible to demonstrate a correlation between osteo- 245 porosis and backache . This is partly because of difficulties with techniques of measurement of osteoporosis covered especially in the actual skeleton; densitometry/ is likely to be of great assistance 129 in improving this gap in our knowledge Ochronosis may be a rare cause of low back pain, as may other 180 2 34 calcifications ' possibly due to pseudogout (chondrocalcinosis). 41.
The calcification of ochronosis tends to be associated initially with 180 stiffness rather than pain; acute disc herniation may occur
INFLAMMATORY ARTHRITIDES:
Although these may arise (ankylosing spondylitis}, rheumatoid arthritis, gout) the incidence is low compared with the incidence of back complaints. Gout has probably not been fully eval• uated as a cause of low back pain. As entities basically involving only the synovial joints, these will not be detailed here.
INFECTION: Infection may be a cause of acute or chronic low back pain, whether an acute purulent (e.g. staphylococcal) or chronic granulomatous process (e.g. tubercular). Even hydatid disease may be 179 a cause of thoracic back pain . Discussion of these also falls out• side the scope of this paper. MALIGNANCY: An occasional cause of low back pain in the older pa- 104 tient, e.g. as sacral metastases , or multiple myeloma.
TRAUMA: Major trauma is not a common cause of low back pain.
Only 15% of ROWE's series could relate an injury to the onset of low back pain . CAPLAN, FREEDMAN and CONNELLY did not think that disc degeneration was due solely to aging and found a relationship between narrowing of the disc spaces and previous injury but not between disc 42 changes and heavy work without injury . This study again is based on radiological evidence. HULT found that in 60-65% of those who had 42. lumbago or sciatica attacks the symptoms had appeared without a 128 history of trauma or lifting strain . Repeated minor trauma may be a factor, but difficult to demonstrate except as in the next section. OCCUPATIONAL FACTORS: " the relatively high prevalence of disc dis• ease among heavy manual workers is strong presumptive evidence of the causal relationship but this is less clear cut than in the case 7 of osteoarthrosis of the limbs" . However, the links between muscular effort and work and pain of indeterminate origin are much less cer• tain. Work by the Arthritis and Rheumatism Council in Edinburgh and Manchester demonstrates that although sickness absence rates do seem to be related to heavy jobs, age standardized complaint ratios in 18 widely ranging occupations showed no obvious correlation with heavy o jobs . Radiological evidence of disc degeneration is more common in 152 heavy workers . HULT demonstrated a higher incidence of symptoms described as the lumbar spine syndrome in those engaged in heavy 128 work (64.4%) than in those in light occupations (52.71) . Incapac• ity to work was again much more prominent in those doing heavy work than in those in light occupations, demonstrating the greater socio• economic importance manifested in lost time in heavy occupations. Because of the high incidence of spinal symptoms in all occupational groups and a moderate difference between the light and heavy occupations 43. he concluded that heavy work could not be a fundamental cause in the changes causing these symptoms. He felt that objective clinical signs of restriction of movement, tenderness on pressure suggested that the changes in the lumbar spine were the most common causes of the syndrome. He did not suggest any trigger mechanism for these coming about or for complaints of back pain in the younger patient:. GOODSELL showed a slightly disproportionate number of laborers in his series of 406 1am- mectomie+ • s9 4 As part of the work of the Industrial Survey Unit of the Arthritis and Rheumatism Council job analysis was performed in terms o&i'.equired 7 muscle activity, posture and site conditions with precise grading . Increasing effort by back, arms or legs significantly increased the likelihood of disc disease in particular (this being a diagnosis based on history and physical alone) but outdoor conditions showed no such influence. TROUP has detailed the variations in permitted maximum weights 261 and heights over which they may be lifted but feels that limitation of absolute maximum weights may only be a part of the answer in prophylaxis as repeated lifting of lesser weights may be harmful, particularly if associated with accelerative or shear stresses. KOSIAK et al felt 50 lbs to be a critical value above which time 147 loss was more likely to be severe . TROUP et al are continuing a prospective trial with detailed job description and laboratory anal- 265 ysis of work stress : the results of this should be highly 44. illuminating.
ILLNESS VULNERABILITY:
It has been shown that a small percentage of people account for a disproportionate amount of illness while another small number are disproportionately healthy, according to a series of studies by HINKLE . The figures for CP. AIR (VANCOUVER) reflect this trend, showing 97% of leaves of absence to be taken by 21% of 113 staff . It has also been shown that the illness susceptibility of these people is general (i.e. to different types of illness) rather 259 than specific . It was shown that these illnesses tend to cluster, so that one-third of an individual's illnesses are likely to fall into one-eighth of his years. This can manifest itself by two mechanisms, probably either independently or together: a great illness-reporting factor can be shown and greater actual morbidity and even mortality. THURLOW suggests that the "total man" may react to a threatening change with a wide variety of responses: behavioral, endocrine and 259 immunologic, which may then increase illness or accident proneness
Once the symptomspattern has been formed, it is possible for per• petuation to occur.
PSYCHOLOGICAL:. Those with physical illness or even increased illness vulnerability may show psychological abnormality, according to STEWART
FORD and LAM pointed out the importance of psychological assessment 81 of the patient with low back pain . PHILLIPS showed that neurotic 45.
triad abnormalities in the Minnesota Multiphasic Personality Inventory were more marked in in-patients with low back pain than in those with fractures
MAGORA demonstrated a high incidence of low back pain to be re- 164 lated to high levels of education , while MACNAB found that lower
intelligence was a determining factor in the 'failure1 of lumbar
intervertebral fusion. Many authors agree that psychological ab•
normality is important in the pathophysiology of low back pain be- forr e or after+ r surgery 55, 56>>>>>>>>, 95, 100, 106, 267, 273, 275, 283>, 285 but it is rarely quantitated and has only been studied in two con- 209 272 trolled populations ' : the psychological aspects of one being 272 yet unpublished
"This review has indicated that the growing interest in this field is a comparatively recent development and that much research still requires to be done to establish more clearly the. nature and cause of many :(jm^£\ll?ostee'l5g.f^ pains especially in the back.
back pains are numerically most important rheumatic causes of absence and permanent disability and their effects are formidable in terms of loss of earnings; those affected also make 7 heavy demands on medical services." 46.
MANAGEMENT OF LOW BACK PAIN.
It is not relevant at this point to discuss the detailed manage• ment of the patient with the complaint of low back and/or sciatic pain. Nor will the methods of arrival at a specific diagnosis be detailed: by consulting the appropriate references these methods may be learned. However, an outline of such methods is presented as they are of importance in management of the patient eventually requiring fusion, which is essentially an end-stage procedure.
DIAGNOSIS AND ASSESSMENT
HISTORY AND PHYSICAL EXAMINATION: These two subsections are covered i.n detai, . ..l . b,y many authors 38, 40>>>>>>>», 53, 61, 126, 148, 223, 225, 234> , 242, 280
RADIOLOGICAL EXAMINATION: Many opinions are found regarding the appropriate features to be searched for on plain x-rays, usually comprising a combination of these views - antero-posterior, lateral, two obliques, spot lateral lumbosacral, uptilt anteroposterior lumbo• sacral and bending films in two planes10' 61' 68' 69' 70' 87' 129' 132, 143, 143a, 144, 183, 186, 247, 281
Contrast studies include myelography, discography and epiduro- graphy; each has a specific, carefully delineated role to play, 47. each has a high rate of false negatives and false positives^1'
100,' 102,' 141,' 142,' 238, ' 277 .c Furthe., r wor, k may soon allo,, wr ful,, l stereoscopic visualisation of the lumbar spine through holography"*"^.
PSYCHOLOGICAL ASSESSMENT: Many authors have stressed the importance of psychological factors in low back pain, particularly with regard 15 51 183 249 to failures of surgery ' ' ' , but very little has been written to assist in the interpretation of psychological abnormality 95, 201, 202, 209
ELECTROMYOGRAPHY: Suggested for use in evaluation of the problem 92 249 patient, particularly before anterior fusion ' lower limb electromyography was reported in use by GURDJIAN in 517 patients, showing slightly better accuracy at the fifth lumbar disc level than contrast myelography (64.8% vs. 61.8%). Electromyography of the trunk muscles in the patient with low back pain is still in the in- vestigationa+. l, stag+ e63 , ' 279a,' 292
DIFFERENTIAL SPINAL ANAESTHETIC: The methods described by AHLGREN et al, and BROTHERS and FINLAYSON were found of value by them and 92 183 by others ' . This procedure helps discriminate between pain predominantly of peripheral or central origin at the time of the examination. COMPUTERISED DIAGNOSIS: Early work on Bayesian analysis of patient data promises that the use of computer-assisted diagnosis may become 48. helpful 98
CONSERVATIVE MEASURES OF THERAPY
For the purposes of simplicity, modes of management are described
here without reference to chronicity of disease, according to which 280 they will be of varying usefulness
PREVENTION: a) Epidemiological research, identification of risk factors, patient education, improvement of
occupational conditions216.
b) Maintenance of good overall physical condition and, muscula. r ton. e 127', 148
REST: The time-honored principle of rest, including bedrest if necessary, is affirmed by all authors although bedrest prolonged beyond one month is 61 not likely to be of benefit . The load on the disc is considerably reduced in the reclining
.+. 191 position
53 TRACTION: Still recommended by some this has been shown to have negligible effect in reducing the load 191 on the lumbar intervertebral disc in vivo . It
is probably of most value as a means of enforcing
bedrest in the recalcitrant patient. 49.
ANALGESIA: This is mentioned as a basis of conservative
therapy; narcotics should be used only in the
emergency phases of treatment12'''.
MUSCLE RELAXANTS: Used for the benefit of central and peripheral
effects162, diazepam is representative and has been shown electromyographically to reduce muscle 12 spasm . It has been suggested, however, that muscle relaxants should only be used as an 127
adjuvant to bedrest and in one such double-117 blind trial they were shown to be ineffective DE PALMA and ROTHMAN suggest the major use of
relaxants to be in the acute phase61. DIET: Diet is of importance in the obese patient to 127 reduce stresses on the lumbar spine
PHYSICAL THERAPY: The aspects of concern hereare heat, posture and exercise. Heat is for symptomatic relief of pain, the aims of therapy concerned with posture and exercise: are more fundamental. Postural correction and education is thought to ease biomechanical stresses on painful joints in the low back and
exercise to develop musculature to sustain im-
proved, postur. e 40', 61', 72', 127', 148', 280 50.
LUMBOSACRAL IMMOBILISATION:
Widely used as corset or brace in assisting
therapy, or as a plaster cast to assist in
diagnosis, the mechanism of action is unclear
and the clinical usefulness not proven. As they
do not produce immobilisation and may increase
muscle activity, it is possible that the mechanism
of action is by increase of intraabdominal
pressure or by limitation of motion in certain
directions61' 127> 163> 208> 268.
EPIDURAL INJECTION: As rest may produce relief of pain by allowing
inflammation to subside61, so may suppression of inflammation be of importance in the use of epi• dural steroid injection, which has found success in many hand, ,s 37', 55', 238', 28.5
OPERANT CONDITIONING: For the chronic patient not in a position to be
helped by physical methods, modification of pain 83
behaviouB may be of benefit .
REHABILITATION: This vital part of the treatment of any condition
170 'i')/; 0 71 must be on a personal level ' ' as well as on occupational basi-i s 135', 182' , 183' , 21.0 51.
Compensation on a practical! basis may be an 135 210 essential part of rehabilitation ' ,and may influenc. ri e recovery169 a
The results of the nonoperative treatment of low back pain will 102 be discussed in conjunction with the operative treatment
OPERATIVE THERAPY
Surgical treatment will be considered under six headings: manipulation, discolysis, surgery of specific 'non-disc' lesions, discectomy, decompressive laminectomy and fusion.
MANIPULATION:
Although this may be considered an aspect of physical therapy, and may defer the need for surgery, it is an operative method. It is practiced by a limited number of physicians primarily because of lack of training, partly because of lack of knowledge of the mechanism ofr actio+. n37 ', 38', 54', 55', 56', 127', 157', 280
DISCOLYSIS: Still a controversial procedure, chemonucleolysis has been per• formed with two enzymes: collagenase and chymopapain. Each is specific; collagenase breaks down collagen to proline, hydroxyproline and glycine (mainly), while chymopapain attacks the protein mucopolysaccharides, 52.
forming keratosulfate, chrondroitin sulfate and protein. SUSSMAN
states that collagenase, which will not attack the cell membrane and
is rapidly inactivated by serum, is much safer than chymopapain which has been more widely used but has been associated with fatal sub- 254 arachnoid hemorrhage, but that further investigative work is needed
SPECIFIC 'NON-DISC SURGERY:
Appropriate surgical or other therapy may be required for these potential sources of pain: sacral nerve root cysts, dural cysts, narrowing of the sacral canalor spina bifida of SI with impinging
L5 spinous process^9' 61' 248. Removal of the posterior vertebral elements may be required for spinal stenosis 231 , spondylolisthesi9s0 241 of Paget's disease ; excision is required for chordoma or occasion- 234
ally for 'kissing spines'
DISCECTOMY: The indications for pre-, intra- and post-operative techniques and complications of disc removal (often incorrectly referred to as 2 15 29 6*7 laminectomy) have been well covered in the literature ' ' ' ' 88, 90, 100, 101, 102, 171, 177, 194, 195, 196, 213, 214, 217, 143, ' as well as in the standard orthopedic and neurosurgical texts. Here it will suffice to consider the results of treatment. Table 2 summarises the results of discectomy with or without
fusion as given by several authors. The only two studies comparing the long-term follow-up of patients with discogenic pain treated 53. surgically or conservatively fail to demonstrate any differences in 102 196 the overall results between the two groups ' . Both point out that a strict comparison is not possible as initial selection of the patients biases the results; a prospective controlled trial with 196 random assignment of subjects is suggested . Earlier studies demonstrating a degree of preference for surgical treatment were based on short term follow-up^' ^' ^. HAKELIUS has shown that in selected cases where a definite disc protrusion is found 102 earlier return to full activity may be possible with discectomy 124 177 Bilateral disc exploration probably produces better results ' , recurrence is more frequent following unilateral discectomy. Most of these quoted authors eventually felt that in view of the increased convalescence and morbidity, with little difference in results, 15 100 fusion should be performed only at a later date if necessary ' '
194, 280^ pew kave SUggested that fusion should be performed simul- 227 252 taneously ' ; results then have not been found significantly better and no recent arguments have been given for the practice (See also following section). Decompressive laminectomy may be used as an adjuvant to disc• ectomy if the pain is atypical and it is felt that the sagittal diameter of the canal is narrowed29' "^9' 231. 54.
LUMBAR INTERVERTEBRAL FUSION.
The rationale of the operation of lumbar intervertebral joint arthrodesis is that pain in certain cases arises from a mechanical derangement occurring at one or more parts of the intervertebral joint and hence can be abolished by elimination of motion at that particular joint. The history of the operation has been well review- 75 720 ed by BICK arid ROLANDER .
INDICATIONS: The main indication for arthrodesis of the spine 53 was tuberculosis at the time of HIBBS and ALBEE . It is still of primary importance in selected cases of pyogenic or tubercular spon• dylitis, but these fall outside the field here being considered. Indications for lumbar intervertebral fusion have included the following: 216 258 1) Narrowed disc space with vertebral displacement '
2) Spondylolisthesis57' 211' 228' 252' 258' 286 3) Certain congenital anomalies, e.g. hemivertebra, sacrali- satio+. n 127', 228', 252', 258 194 252 4) Failure of pain relief by previous laminectomy '
r. c • r r • 211, 216, 228, 258 5) Symptomatic non-union of a fusion ' ' ' 252 258 6) Disc herniation in heavy worker:. ' 7) Instability127' 228' 252 55.
8) Long-term backache2^2 127 252 9) Disc space entered at surgery with no protrusion found ' 228 10) Retrospondylolisthesis 11) Charcot spine34 211 12) Spondylolysis For a detailed historical review of the indications for fusion, the reader is again referred to the introductory section in the treatise by ROLANDER220. The maj.<3r controversy regarding fusion concerned its role at the time of discectomy, suggested in the initial paper of MIXTER and BARR especially if there was instability of the spine. A multitude of papers were publishe, d,15 '>>>>»>, 52, 100, 101, 203, 213, 227,• 27 6 +th, e cumu- 194 lative opinion was expressed by NACHLAS , as Chairman of the Research Committee of the American Orthopedic Association, that results of discectomy with simultaneous fusion were slightly better, with partic• ular reference to a slightly lower incidence of residual backache in those with added fusion. However, the Committee saw no reason why fusion could not be performed at a later date, particularly in view of the fact that, at that time, the average hospital stay was 15 days where excision only was performed, 58 days for the combined operation. The types of fusion and their major features are outlined in
Table 3 . The three major categories are2^' 220: 56.
Posterior fusion (e.g. HIBBS, ALBEE, BOSWORTH types)involves placement of bone graft material between laminae and/or spinous pro• cesses.
Posterolateral or intertransverse fusion (e.g.WATKINS) in which blocks or slivers of bone are placed between the transverse processes. This may be combined with the posterior fusion.
Interbody fusion (e.g. CAPENER, MERCER, HARMON) may be anterior or posterior (more commonly the former).
In each case, the principle is the same: to cause bony fusion, usually by applying autogenous cancellous bone graft to the prepared
surfaces of adjacent vertebrae. Internal fixation may be applied in the form of screws 30 ' 140' 207 or plates15 9 , but this is only to assist in immobilisation until the bone becomes mature and solid.
RESULTS: It was shown by SMITH in 9 autopsies on patients 25 who had had Hibb's fusions that solid bone resulted , and it was subsequently assumed that solid bony fusions should provide relief from pain and that pseudoarthrosis would generally be associated with pain. However, ROLANDER demonstrated experimentally that although posterior fusion has a stabilising effect and causes redistribution of the load on the disc, the intradiscal pressure is reduced only when loads are applied near the fusion and increased strain may re- 220 suit from more anterior vertebral unit loading , which would seem
to approximate the in vivo situation. The disc was also found to be 57. essential for weight-bearing, as excision resulted in fracture of the posterior parts on loading and ROLANDER felt there would be less chance of achieving a stable posterior fusion where discectomy has been performed. NACHEMSON and MORRIS showed in vivo that loads in discs spanned by a posterior fusion in two patients were only about 193 30% less than would have been anticipated in the absence of fusion In the one with a pseudarthrosis, further loading increased the intra- discal pressure to a value similar to subjects without fusion. In the other, surgically demonstrated to have a successful fusion, the force on the disc was proportionately reduced by further loading. However, NACHEMSON's load figures are calculated from nuclear pressures and do not convey any information of asymmetry of disc loading. Clinically, the success of fusion has usually been evaluated according to the subsequent rate of pseudarthrosis^' "^'153 ' 185' 207, 258, 269^ additional information concerning work habits, and reported pain patterns: in fact LEVY et al felt a solid fusion to be the most important single factor in obtaining a satisfactory 153 result . However, several authors have produced results casting doubt on the functional significance of pseudarthrosis^' ^' In a series of 594 patients with a total of 1165 fused levels, CLEVELAND et al showed the overall pseudarthrosis rate to be 16.7%, varying from 3.4% in lumbosacral fusions to 33.3% in L3-S1 and L2-S1 fusions^. They found that of all patients in whom pseud• arthrosis is developed, 41.4% were relieved of the pain and disability 58. present before operation. Application of a test of independence
(with YATE's correction) to their data shows that in fact pseudo- 2 arthrosis and relief of pain were not independent (x = 167.45, p < .005). However, the fact that so many patients with proven pseudoarthrosis (and the figures are lower than many series) were still relieved of pain is of great interest.
BARR et al found of 120 multiply-operated patients, those with 16 a solid fusion had a greater chance of having a better result In a series of 448 post fusion patients with a follow-up period of five to seventeen years, DE PALMA and ROTHMAN demonstrated pseudoarthrosis by motion on bending x-rays in 8.91 or thirty-nine patients60. This group was controlled by thirty-nine others with the same diagnosis and operation but a solid fusion. The incidence of complications, time of return to work and to previous activity levels, attitude to surgery, relief of symptoms and pain distribution patterns were the same in both groups (no significant differences on Chi-square analysis). They felt that pseudoarthrosis per se should not be considered 'failure' of a fusion operation. Even the presence of a solid combined anterior and posterior fusion only occasionally gives complete pain relief119. The diagnosis of pseudoarthrosis is also difficult, as methods include various techniques from clinical examinations with evidence of tenderness up to and including surgical exploration, recommended 59.
159 by CLARK . X-ray examination probably is not conclusive until two 57 119 years have passed ; even then it is unreliable o . However, more series give the results of surgery in terms of the incidence of pseudoarthrosiA •s u havin• g primar• y •importanc + 16e , '30 , '34 , '108 , '153 , ' 185, ' 207, 211, 216, 215, 252, 258, 269 , , . »»»»»» than those who use predominantly clinical considerations for success23, 41' 46' 60' 6^' 140' 194.
Hence when we consider the reasons suggested for 'failure' of the operation, the bias is towards those factors tending to produce pseudoarthrosis; indicated by an asterisk, (also included here are disability*producing complications). 6 153 211 1) Failure to obtain solid fusion or graft fracture ' ' ' 216, 258, 269 2) Psychologically 'unsuitable' patients16' 89' 233' 2^2' 2^8' 285 3) Cases with complicated compensation claims16' 28^
4) Adhesions of nerve roots +_ their sheaths16' 72' 119' 216' 233 16 5) Pain threshold too low
* 6) Inadequate bone grafting46
* 7) Use of other than autogenous cancellous bone46' 108' 181' 211
* 8) Infection46
* 9) Fracture of a previously solid fusion46
* 10) Crossing of previous laminal defects46
11) Arachnoiditis89' 233
* 12) Fusion of more Hihan one level89' 2^2' 258 89 * 13) Wide laminectomy, providing poor bed 60.
14 Acquired (post-fusion) spondylolysis 6 ' 111 ' 185 ' 222
15 Nerve root irritation by fixation screw1^ 16 Lumbar hernia at iliac donor site - rare 158
17 Donon r site pai.159n ,' 269 18 159 Lateral femoral cutaneous nerve pain 19 Spinan • l-t stenosi. -s 185,' 205,' 244 20 233 Surgical technique 21 01 O *Z *Z Failure to recognise involvement of another level ' 22 Compensation pressures 233 ' 258 23 233 Failure to diagnose other than vertebral pathology 24 233 Cephalad progression of disc degeneration 25 Generalized disc degeneration216' 233' 252' 285 26 Donor site pain (as related to technique: peripheral nerve 252 entrapment)'
27) Obesity258' 285 This list of reasons given for 'failure' of the fusion operation is far from exhaustive of the extremely extensive literature: it is, however, representative. It should be stressed that there is no commonly agreed-upon formula for assessing the results of operation, which are variously based on patient opinion by questionnaire or interview (usually considering only pain patterns and reported work habits), physical examination, radiological examination or a com• bination of the three. 61.
A summary of representative results is presented in Table 4 .
Disability evaluation has not been formerly considered as a
form of assessment of the patient who has had lumbar intervertebral fusion. The concept will be presented in the discussion section. 62.
SUMMARY OF LITERATURE.
It is clear that certain pathophysiological mechanisms are responsible for creating a .potentially painful situation in many individuals. What is not yet clear is why some individuals develop what we clinically understand as pain: behaviour causing a patient social arid economic distress and having profound emotional effects on both patient and family.
Insofar as these structural or pathological abnormalities are of relatively uncertain significance, in the unoperated patient, so are they in the-postsurgical patient, in whom it is just as impor• tant to determine the relative roles of the multiple factors in• cluding the role played by the surgeon himself. The purpose of the study, then, was to ascertain the relative importance of selected measurable parameters and evaluate these in terms of previous work. MATERIALS AND METHODS - PILOT STUDY
The subject materials for. the initial, pilot, phase of the study were all World War II Canadian veterans who had had lumbar inter• vertebral fusion during the seven-year period 1962-$968. The operation had been performed with or without laminectomy at one or more levels for low back and or sciatic pain, and the Boucher technique had been used in all cases. The numbers that could be traeeddand re-examined were limited by geographical situation and availibility of current address to 28 patients, all with a follow-up since fusion of at least two years.
In each case the patient was sent a short explanatory letter requesting his attendance at a specified time at the outpatient department of Shaughnessy Veterans Hospital. Failure to attend on the first occasion was followed by a repeat request, by telephone or letter.
A history and examination coded form was completed as each patient was seen by the author or other orthopedic resident. The format of the examination and design of the forms is discussed in the appropriate section regarding the main phase of the study.
The patient was seen by a psychology graduate student who followed an interview by the administration of several objective tests, include the Wechsler Adult Intelligence Scale, Minnesota 64.
Multiphasic Personality Inventory, Cornell Medical Index and Mooney
Problem Check List. All subjects completed the first two tests, except
•for one who refused the MMPI; the latter two tests were introduced
in the course of the project, after the first three and seven subjects
respectively.
Data analysis was performed in terms of the succes or failure
of fusion, assignation to one of three outcome groups being decided
by the patient's score on an arbitrarily designed rating scale (See
Table 5 ).
It was felt, when trying to decide to which outcome group each
patient should belong, that the relative "success" of fusion is too
often made dependent, in the literature, on such factors as solidity
of fusion or amount of analgesia required, for example. It seemed
that a more comprehensive method of assessing surgery was required
and hence the main categories were selected, relating to employment,
pain, mobility of the lumbar spine, the patient's and orthopedic
examiner's overall impression. With the peak score of 27, the
patients were divided into quartiles, with selection of the lowest
and highest scoring quartiles respectively as the good and poor
outcome groups, the remainder being called "fair" results.
Part of the purpose of the initial phase of the study was to
gain experience in the application of computer methods to patient
data analysis, therefore all patient information was transferred 65. to punched cards and an IBM 360 computer used to display the results as bivariate frequency tables of result grouping vs other variables together with the percentages. The statistical significance of selected intergroup differences was performed subsequent to the evaluation of the displayed results.
MATERIALS AND METHODS - MAIN PHASE
For the major portion of the study, it was necessary to select a group of patients who had.had lumbar intervertebral fusion who were accessible to recall and for whom fairly good medical records were obtainable. Such a group was found in patients initially presenting with a compensable low back disorder. Recent addresses were on the records kept at the Workmen's Compensation Board of British Columbia, especially if any form of contact was being maintained, either because the patient was receiving medical treatment or might still be on some form of compensation payment.
The files were drawn of any patient who had had lumbar inter• vertebral fusion more than two years previously. This was done in a retrograde manner, year by year, until a satisfactory number had been seen. Where the information of patient identification was not avail• able by coded cross-indexing, prior to the summer of 1966, this was sought from the major general hospitals of British Columbia's metropolitan areas.
The patient's medical record at the Workmen's Compensation Board was first summarised for purposes of future reference, while a call-in letter was sent out under the heading of the Orthopedic and Trauma Research Unit, University of British Columbia, stressing the voluntary, research nature of the examination and stating the hours likely to be involved. Recompense for time loss and travel was promised, and in view of experience gained in the pilot study, each patient was requested to bring reading glasses, if used. The letter was personally signed.
Shaughnessy Hospital was used as the place of appointment, because of suitable facilities for all examination procedures and its neutrality compared to the Workmen's Compensation Board premises. If the patient did not appear for the initial appointment, further letters were sent, with subsequent registered letters and telephone calls as necessary to confirm the address or unavailabili of each subject. No one refused to attend, few made attendance impossible by conditions imposed. Correspondence with one or: two was continued at great length to try and achieve a high follow-up 0 rate. Of 141 subjects called, 101 were seen. Six were found to be deceased, call in letters were returned by the post office on 20, about whom no current information could be obtained. Fourteen patients were unavailable for various reasons, either work or
finance-related. On those with whom contact could not be established
in some way, efforts were made to determine if, in fact, these patients had died and, if so, their cause of death. This proved
difficult but some information on our limited data was supplied by
the Department of Vital Statistics in Victoria.
The patient was usually seen first by the orthopedist, who would obtain historical data and administer the Patient Self-
Evaluation Questionnaire (Appendix 1 ) before performing complete physical examination. This would include particularly detailed
evaluation of the lumbar spine and lower limbs. The patient's
opinion of the result of surgery was sought, and recorded, and a
brief assessment of his personality was made. The Cold Tolerance
Test (a form of pain tolerance test) was then administered
(Appendix 3).
Radiological examination involved the use of nine views -
anteroposterior, lateral, two oblique and spot lumbosacral views
and bending films in two planes. If surgery had been more recent
than four years prior to the date of examination and appropriate
x-rays taken elsewhere in the preceding six months, these other
films were obtained instead of subjecting the patient to a repeat
x-ray exposure; this was also done if surgery had been over four 68. years previously and the roentgenogram taken in the preceding year.
The patient's compliance and understanding was obtained and he was told the x-rays might be made available to other physicians at their request.
At this stage he was also reminded that no other information would be released to any other physician or other agency without the patient's written consent, to ensure confidentiality of in• formation and avoidance of any "compensation bias".
The patient was usually provided with lunch before seeing the psychologist, who conducted a structured interview and then admin• istered the psychometric tests used. In most cases the completion of all tests was done at the time of attendance but in some cases the patient was allowed to complete them at home and mail them in.
This was done where performance of the tests was unduly prolonged because of language difficulty or other reason.
The psychological tests selected were as follows:
(1) Cattell Culture Free Form A Intelligence Test. This was substituted in favour of the WAIS used in the pilot study because of difficulties with language experienced with some subjects: the
Cattell having no verbal component.
(2) Minnesota Multiphasic Personality Inventory. Selected as a well evaluated and controlled screen for organic and non-organic personality problems. The Baron ego strength scale, Taylor "At" anxiety scale and the Hanvik Low Back Pain Scales were used to 69. supplement the basic clinical scales. The M.M.P.I. is based on a 566 item questionnaire (Appendix 4).
(3) Beck Inventory of Depression. Used as a more sensitive and accurate measure of depression than the Depression Scale of the M.M.P.I. A 21 item questionnaire (Appendix 5).
(4) California Personality Inventory. An index of personality relating to social functioning, and fairly highly developed. A 480 item questionnaire (Appendix 4).
(5) Kilpatrick-Cantril Self-Anchoring Scale (Appendix 6). In this, the patient is shown, on paper, a "ladder of life". He is asked to verbally describe his worst conceivable life situation in writing at the bottom of the ladder, the most perfect at the top. He is then asked to make a mark on the ladder to indicate his position relative to the extremes at the time of last fusion, the present, and the future (5 years hence). The distance of the marks from the bottom of this ladder is then scored. Data was collected in a standardised fashion and entered on four forms. It was hoped to thus readily transfer the information, on completion of the study, to punched cards for subsequent computer analysis. Inevitably, certain faults became apparent in the design of these forms later in the study and subsequent improvements made, as they were after the pilot study. Basically, data was collected in six relatively discrete sections. 70 .
1) Historical information (history of back condition, of other diseases, family and personal history). Examiner administered.
2) Patient self-evaluation information. A reproducible way to assess functional impairment and activities of daily living is by written questionnaire. In most cases patients were left alone to complete this. Because of language difficulty, a few subjects re• quired assistance.
3) Physical examination. This included an overall examination of the major systems with attention to detail regarding the low back and lower limbs. A brief assessment of personality was made by the orthopedist and he also administered the Cold Tolerance Test.
4) Psychological patient data - mostly historical. Obtained by the psychologist in his interview.
5) Psychological test data. This was collected in the usual fashion for the Cattell Culture-Free Intelligence Test, the
Minnesota Multiphasic Personality Inventory, Taylor Manifest
Anxiety Scale, Beck Depressive Inventory, Kilpatrick-Cantril Self-
Anchoring Scale and the California Personality Inventory.
6) Radiological data. This entailed the interpretation of the standard lumbar spine views and measurement of specific items in these x-rays. X-ray interpretation was completed at the close of the clinical phase of the study.
Data processing was performed with the assistance of the 71.
University of British Columbia Computer Centre. All data was trans• ferred to punched cards and subjected to the U.C.L.A., Frequency
Count Routine, providing a cell count and percentage, the range, median, mode, mean, standard deviation arid standard error of the mean for each variable. This program also produces a simple histogram for each variable, thus providing at a glance the approximate subject distribution.
To enable a numerical index of "success" of the intervertebral fusion to be developed, factor analysis of 20 variables falling into
12 categories was performed, described in a later section. This factor analysis was performed at the University of British Columbia
Computer Centre, using the program "UBC FAN" developed by Jason Halm from the UCLA BMDX 72 program (1971). It was decided to name the first variable on the unrotated matrix "success" and to use this in sub• sequent analyses.
An intercorrelation was then made of the patient's scores.on
"success" and 239 of the variables recorded, excluding all the re• membered information for 'one month before fusion' on the self- evaluation form and the multi-level nominal variables, such as occupational category. Some data transposition was necessary for this to improve the ordinal or quantitative characteristics. The program
UBC C0RR by Ann Floyd and James H. Bjerring of the University of
British Columbia Computer Centre (1969) was used, data being pro• cessed in blocks of 60 variables, 120 being the maximum number 72.
acceptable in a single run. Correlation methods used were the corre• lation ratio (ETA), Jasper's coefficient of multiserial correlation (M) and Pearson's coefficient of correlation (R) as appropriate for the variable types, with suitable significance tests. The p (prob• ability of significance) values were entered on a matrix for evaluat• ion (Table '6).
Fifty; five of the variables showing significant correlation with "success" (p<.0T), excepting those used in its initial deter• mination, were then again subjected to factor analysis, the program "UBC FAN" again being found most useful. The seventeen (17) resultant orthogonal factors were assessed and described according to the load• ings on the Varimax rotated matrix and their nature confirmed using oblique rotation. The factor scores for each patient were then correlated with "success" and the importance of the factors in accounting for the variance of "success" thus determined.
RESULTS - PILOT STUDY (28 WW2 VETERANS)
The results will be summarized here and certain aspects high•
lighted, as a primary aim was to evaluate the methods for the main phase of the study and to allow for their modification.
The method of grouping the subjects was described in the appro• priate section (p 54 ). HISTORICAL
Age (mean) in years: Group 1 2 3 Overall
At examination 50 54 55 53.3
At onset 33 27 26 27 Time lapse onset/fusion 9 18 15 15
Sex: Male 26 subj ects
Female 2 subjects
Occupation: Group 1 2 3 Overall
Unable to work permanently 15% 21% 71% 32% > One week lost in previous 2 yrs 0 57% 100% 54%
Return to work (after surgery) within 4 months: 1 2 3 Overall
43% 36% 0 28%
Pension: Group 1 2 3 Overall
D.V.A. pension for back 28% 78% 85% 68%
Medical history: 21% had no other health problem on enquiry. 14% of each group 2 and 3 had some gastrointestinal complaint compared with none in group 1.
Back history: Trauma of some type was associated
with the onset of symptoms in 57% of group 1, all of group 2, 86% of
group 3, with a significant direct
relationship to the severity of
the back condition on review.
Operative history: Group 1 2 3 Overall
Single admission 57% 21% 0 25% More than 1 fusion 0 30% 43% 25% All those having one or two pseudo•
arthrosis repairs fell into the fair
or poor group.
Symptoms: 11% of the total were symptom-free; pain alone was the dominant symptom in 64%. It was felt in the back alone in 32%, predominantly in the back in 32%, in back and legs equal• ly in 11% and the legs alone in 7%.
PHYSICAL
General: 43% of the total demonstrated some abnormality on examination which
would include, for example, a single
operative scar. 22% showed some ab•
normality on rectal examination 75.
(group 1, 0%; group 2, 46%; group 3,
15%) which often took the form of
coccygeal tenderness: no detail was
recorded.
Gait: A mild abnormality of gait was found
in 11% of the total (28% of group 3).
Cervical or thoracic spine: Group 12 3 Overall
Limited motion or tenderness 0 35% 57% 32%
Lumbar lordosis': A significantly greater degree of
abnormality was seen in the poorer-
faring patients, with a milder
association between result grouping
and muscle tone of the abdominal
and paravertebral muscles.
Tenderness: Group 12 3 Overall
43% 86% 100% 79%
Usually localised to a spinous pro•
cess but not apparently related to
the fusion level.
Neurological: Group 1 2 3
Impaired straight leg raising 0 65% 71%
Calf or thigh asymmetry 0 43% 34%
Sensory impairment 0 36% 57% 76.
Result of surgery: Group 1 2 3 Overall Permanent definite improvement 100% 35% 0 43%
Partial improvement 0 57% 14% 29% Temporary improvement 0 0 57% 14%
Worse or 'other' 0 8% 29% 14%
Under the same circumstances (the patient would):
Group 1 2 3 Overall
Accept surgery again 100% 71% 71% 79% Refuse surgery again 0 7% 14.5% 7%
Undecided 0 22% 14.5% 15%
RADIOLOGICAL
Congenital anomalies: Two patients, one in each of groups 1 and 3, had a separate facet epi• physis, each at a single site. Spondylolysis was seen in a single patient at the L5 level.
Myelogram dye: A few drops seen in 29% of group 1,
57% of group 2, 86% of group 3.
Level of fusion: Group 1 2 3 Overall
L5 SI 86% 36% 0 39%
L4 SI 14% 50% 71% 46% 77.
Groups 2 and 3 each had one patient
fused from L3 to SI and one fused
at the L4 5 level.
Pseudoarthrosis: None seen in this series although four patients had previously been operated on for this. All had had Boucher fusion.
Screws: The presence of bent or broken screws did not correlate with the result group.
Degenerative changes: More changes of disc degeneration were seen in the lumbar spine of the poor result patients, as evi• denced by the presence of osteo• phytes (good correlation) lesser overall disci' height and increased posterior joint subluxation. The presence of traction spurs and measures of retrospondylolisthesis.
Kissing vertebral spines: These were seen in 40% and corre• lated neither with the results nor with the presence of spinous tender• ness in the same patient. 78.
Lumbosacral angle: Group 12 3 Overall Mean angle (degrees) 137 139 141 139 These differences did not reach significance at the p < .05 level.
PSYCHOLOGICAL For details of these see WILFLING ; the results are summarised here. The mean I.Q. (using the W.A.I.S.) was 107.2, showing no correlation with the groups. There was no differ• ence between the group in their educational background. 59% of the total had a documented history of psychopathology, ranging from schizophrenia to alcoholism, but uniformly distributed across the groups; most had had their referrals postoperatively. The differences in M.M.P.I. profiles are illustrated in Figure 2. Group 2 shows the "conversion V" configuration of the neurotic triad (scales 1, 2, 3) with 1 and 3 (hypo• chondriasis and hysteria) showing a 79 .
greater elevation than 2 (de•
pression).
DISCUSSION - PILOT STUDY
After performance of the pilot study, certain conclusions were
reached, the implications of which could be further explored in the main phase. These conclusions were as follows:
1) Posterior lumbar spine fusion may be associated with few com• plications and have a very good fusion rate, yet still fail to re•
lieve disabling pain in over one-third of the patients who remain permanently unemployed because of back pain, while over one-half may
still lose some time at work because of backache.
2) The early onset of the disease and a larger time lapse from
the onset of symptoms to fusion are associated with poor results.
3) Poor socioeconomic status of the patient may be associated with a poor outcome of spinal fusion.
4) The patient with poor surgical results may suffer more from
other disorders such as poor muscle tone, deficiences of the cervical
and dorsal spine, or gastrointestinal system.
5) Multiple procedures are associated with poor end results due
possibly to progression of degeneration, inadequate preoperative
patient selection or the adverse psychological effects of multiple 80. surgery, or to greater preexistent psychological abnormality.
6) Poor results are associated both with evidence of more ad• vanced disc degeneration and more severe psychological abnormality.
The reasons for the association require further investigation.
7) Psychological investigation is useful in the identification of patients with poor surgical results, and it might be that through preoperative psychological assessment the number of failed back surgery patients could be reduced.
These findings were borne in mind in the design of the major study, and at the same time they have provided information of use in the clinical setting. However, a detailed discussion of the problems concerning the etiology of low back pain and in particular the possible causes for failure of the operation of lumbar inter• vertebral fusion required more sophistication of experimental approach and hence is deferred until the results of the second phase are considered. 81.
RESULTS OF THE MAIN PHASE (100 W.C.B. PATIENTS).
HISTORICAL DATA.
Of 141 patients mailed a call-in letter, 101 attended. Twenty letters were returned by the Post Office for patients whom we were unable to trace. The fact that there was no current address at the Workmen's Compensation Board implied that they were not receiving compensation payments. Six were deceased, 14 were unable to come because of pressure of work or financial difficulties (it was only possible to recompense the subjects after they had attended). One patient had to be excluded because of the extreme poor quality of x-rays, taken elsewhere. Percentages are used except where stated, decimals indicate missing data, usually because of failure to answer a question or refusal, by the patient.
Age Mean (years) Minimum (years) Maximum (years) at examination 44.1 22 67 at last fusion 39.7 17 63 at onset of symptoms 34.8 16 59
Time from onset of symptoms to first surgery (Median) 18 months.
Sex Male 92% Female 8%
Birth place British Columbia 31%
Other [.provinces of Canada 41% 82.
United Kingdom 9%
North or West Europe 7%
South, Central or East Europe 10%
Other 2%
Ethnic background North American 48% (North American Indian - 1%)
French or French Canadian 6% British 17%
Mediterranean 4%
North or Western European 14% Central or Eastern European 11%
Occupation This information, obtained for the time of the last fusion operation and the present, showed two-thirds to be skilled workers, one- third unskilled, with one executive and an accountant, employed as a stevedore at the time of surgery. Thirty four per cent felt their work habits were unaffected by their back. Thirty six per cent stated that they had changed to a different job type because of their back disability. Forty-nine per cent had made no change in employment, figures for the actual number of changes for the re- 83
mainder. reflected only the nature of their work.
Time loss Sixty per cent had missed from a few days to
many months of work during the last two years
because of their back problem: 11% were un•
employed (median time loss for the total was
1-2 months).
Medical history Forty - four per cent had a history of "sig•
nificant" illness in the past, evenly distrib• uted across the systems. This would include hepatitis, renal stone, pneumonia, for example, but excluded peptic ulcer disease, which had been diagnosed in 26%, with various modes of therapy received. Another 31% suffered dys• peptic symptoms with perhaps professional or self-medication but without a formal diagnosis being made. Twenty-six per cent had had major abdominal surgery (excluding appendectomy).
Seven per cent had had psychiatric atten• tion prior to fusion, 4% subsequently, 1% both. A further 2% described moderate or severe tranquilliser use.
Three per cent had psoriasis, 23.5% had 84
quite frequent rashes or itching.
Back history Ninety -six per cent experienced the onset of symptoms in association with an episode of
trauma, which was relatively major in 22%. The
total number of back-related hospital admissions
varied from one (12%) to nine or more (7%).
Operative history With a range of 1-7, the mean number of back operations was 1.98. The mean number of fusion operations was 1.47, with a range of one (in 66%) to four (2%). The number of laminectomies ranged from zero (18.2%) to three (6.1%); mean 1.13. Complications of the last operation (as obtained from the patient or his Workmen's Compensation Board file) had been suffered by 28%, (wound infections, 9%), excluding pseudo- arthros is.
The pathology described at the last operation included: No abnormality 26% Bulging disc 16% Herniated disc 9% Pseudoarthrosis 19% Fibrosis and scarring in canal 1% 85 .
Congenital anomaly 4% Combination or 'other' 20% No report 5% Microscopic changes were only rarely looked for. The time missed from work prior to the last back operation varied from less than one month to over 10 years, the median being 4-6 months. The time for return to work varied from less than one month to 'not al all', with a median value of 4-6 months.
Family history It was difficult to obtain a reliable family history due to poor memory or lack of communi• cation with distant branches of the family. The median number of siblings of the father was four; 7.1% admitted a history of back trouble in their father or his siblings. The equivalent figure on the mother's side were five siblings; 4.8% admitting a history of back trouble.
The patient had a mean number of offspring of 2.15 at the time of his last fusion, 2.27 at the present. Nine per cent stated that a single child had experienced some back trouble; 2%:2. 86.
Personal habits Smoking : Non-smoker 281
Cigarettes <10 daily 10%
Cigarettes 10-20 daily 32%
Cigarettes >20 daily 24%
Pipe or cigar (moderate use) 6%
Alcohol : Abstainers 10% Special occasions only 7%
Occasional drink 18% Once or twice most weeks (in moderation) 35%
Weekly drinking evening 7% Daily drink 14% Relies on alcohol 5% Unequivocally alcoholic 1% Ex-alcoholic or A.A. member 3%
Drugs : None 96% Ex-addict of opiate 1% Has tried some 'hard' drug 3%
SYMPTOMS
Pain Patients placed themselves in the self-evalua•
tion scale thus: No pain 17% Mild pain 24%'0 Pain annoying, absent on activity 11% Pain present during activity 15% Moderate pain, interferes with activity or sleep 24% Pain prevents activity or sleep 9% Of those with pain, most had low back pain with or without lower limb pain. Eight per cent of the total had pain in the limbs„alone Pain at other sites described thus:
Interscapular Neck Coccyx
None 54% 51% 66% Occasionally 25% 24% 23% Often 6% 16% 5% Most of the time 10% 9% 6%
Factors affecting pain Improvement Exacerbation Coughing, sneezing or straining 2% 26.3% Sitting on a firm or upright chair 34% 21% Sitting in a comfortable or re• clining chair 16% 35% Lying flat 44% 12% Lying curled up 36% 18% Walking 23.2% 29.3% 88.
Improvement Exacerbation
Bending 4% 52%
Lifting 1% 51%
Heat 50% 0%
Cold 2% 41% Manipulation 7% 8%
Corset or orthopedic type belt 291 5%
Analgesic such as aspirin 22% 0% The percentage unaccounted for in each category is provided by those who indicated "no particular effect on the pain", "have not tried it" or "cannot tell". In 54% pain was either absent or bore no relationship to the time of day while in the remainder the pain was time related, usual• ly being worse in the evening or night.
Other symptoms Stiffness : noted in the back and/or lower limbs by 67%. Weakness : this was felt by 55%; 11% bilaterally, 23% in the left leg, 21% in the right leg. Sensory change : described by 60%; 18% bilaterally, 20% in the left leg, 17% in the right leg, and 5%
in other parts (e.g. one ulnar neuropathy). Sleep impairment : 42% said they experienced back discomfort as
a cause of difficulty in sleeping. 89
ACTIVITIES OF DAILY LIVING
Household chores: 70% stated they could manage to carry a heavy suitcase, mcve heavy furniture or do heavy digging in the garden; the remainder described various degrees of limitation. Four per cent could manage nothing in the house.
Self-care: 71% described total independence, the remainder stated a need for help with some aspects of self-care such as dressing.
Flexibility: 49% could descend into or rise out of a chair without discomfort while the others found that the act of sitting and/or rising was painful. 54% stated they were able to retrieve dropped items from the floor without difficulty; 42% would experience difficulty, 4% could not pick up things from the floor.
Mobility: 53% found no limit to the distance they were able to walk, 21% have to stop after a half-mile be• cause of discomfort, 17% after 2-3 blocks, 9% had even less range. Similarly, 48% found back- related discomfort would mildly or moderately
limit their ability to drive while 9% could 90 .
drive, at most, locally only. 52% had back-
related limitation of ability to ride in a bus
or car, with riding discomfort being usually
more pronounced than difficulty mounting or dis•
mounting .
Work and financial: Work habits have been described. Mean income (recorded as $ 100's per month) ranged from $ 100 to $ 400 monthly, with a mean of $ 852 (S.D. 530), 13% felt themselves to be comfortably off, 33% stated they were free of debts but would like to have more money in re• serve, 45% admitted to small debts and 9% found themselves in a fairly serious financial posi• tion.
Marital: status was as follows: Single 7%
Married (one marriage only) 65% Married (more than once) 17%
Common-law marriage 4% Separated 1% Divorced 3%
Widowed 3%
Regarding contentment within the existing marital framework, the 91. following responses were obtained: Single at present 13%
Happy and fairly secure 62% Fairly happy, but obvious ups and
downs 18% Relationship not very good 6%
Likely to split up soon 1%
Sexual problems werealso categorised:
No back related sexual difficulty 62% Certain positions necessary because of back pain 7% Frequency limited by back pain 14% Both the above are true 17%
Social life: Limitation of miscellaneous social activities was considered: No back-related limitation 48% Some type of activity, reduced frequency 13% Change to easier activities 28% Very little possible because of pain 11%
Children: None under age fifteen at home 46.5%
Able to' work and play with them 40.4%
No rough games or lifting possible 8.1%
Very easy games, talking or reading only 4.0%
Cannot share activities at all 1.0% 92,
General quality of life:
Enjoy life 44% As above, but less than before back
trouble 39% Back problem spoils things most of the time
Life is only just tolerable because of the back brouble
Enjoyment of life more affected by other problems
PHYSICAL FINDINGS
PHYSICAL 76% were described by the examiner as being normal and healthy; 20% appeared overweight for their height; 4% appeared pale and thin.
Blood Pressure: 85% had a normal blood pressure, 14% a diastolic blood pressure over 90 mm. Hg., 1% diastolic over 120 mm. Hg.
Body dimensions: The mean weight was 75.9 kg. Mean body height was 173 cm.
A measure of obesity for correlation was expressed
weight_code 1Q d d ,£at£act, height code ' 93.
ENT: 88% had no ENT abnormality.
The abnormality in 12% was usually a perforated tympanic membrane.
Chest: 4% with abnormality had emphysema or a thoraco•
tomy scar.
Heart: 3% demonstrated abnormality, none requiring re•
ferral .
Abdomen: Abnormalities were categorized thus:
Normal 7-5% Obese (marked) 2% Two or more scars 18% Both the above 2% Hernia of any type 3%
Rectal: Normal 74% Fissure and/or hemorrhoids 9% Coccygeal tenderness 6% Tenderness of sacrotuberous ligament. 5% Coccyx and ligament tender 3% All three 1% Refused 2 % 94.
ORTHOPAEDIC EXAMINATION
Stance: Normal 64% List to right 14% List to left 16% List forward 6%
Gait: Normal 93%
Right leg limp 1%
Left leg limp 4% Difficulty both legs 1%
Problem with recent foot operation 1%
Lumbar curve: Normal lordosis 48% Flattened lordosis 42% Kyphosis 1% Scoliosis - right convex 2%
Scoliosis - left convex 2% Flattened and right scoliosis 3% Flattened and left scoliosis 2%
Pelvic tilt: Normal 90% Left side higher 10%
Paravertebral muscle tone: No paravertebral spasm 84% Left-sided spasm 2% Bilateral 14%
Abdominal muscle tone (standing):
Normal 77% Obese, fair tone 16% Not obese, but poor tone 2% Obese, poor tone 5%
Cervical spine: Normal
Limited motion 4% Tenderness (axial or local) 16% Other abnormalities (e.g. curvature) 7% Overlap of these categories accounts for a total greater than 100%.
Upper limbs: Normal 83% Shoulder crepitus on motion 4% As above, limitation of motion 1% Neurological impairment (ulnar palsy) 1% Other 11% The last category included scars, missing digits etc.
Thoracic spine: Normal 94% Abnormal curve 3% Limited rotation 2% Marked tenderness Range of motion; Lumbar spine.
Cervico-sacral increment:
Distance measured from C7 to SI spinous process
and the increase on flexion recorded.
>8 cms , 14% 7.1 - 8-cms 27%
6.1 - 7 cms 25% 5.1 - 6 cms 16%
4.1 - 5 cms 9% 3.1 - 4 cms 7% 2.1 - 3coms 1%
1.1 r 2 cms 1%
Finger-tip reach: Touch toes 14% Below mid-tibia 24% Mid-tibia 39% Touches knees 17% Mid-thigh 6%
Paravertebral muscle spasm on flexion: None 80% Moderate 15% Marked 5% 97.
Extension estimation:Normal 3%
21-30 degrees 26%
11-20 degrees 42%
1-10 degrees 25%
0 degrees 4%
Pain on extension: No 66%
Yes 34%
Lateral flexion: A combination bilateral index was used for this, based on a coding for each side, so that a score of 0 would indicate normal lateral flexion; 6, inability to reach beyond mid-thigh on either side.
The frequencies were: 0 12% 2 29% 3 14%
4 35% 5 7% 6 3%
Passive hyperextension:
Full, pain free 57% Slight pain, normal limit
Mild pain 10% 98.
Moderate pain Severe pain - relieved by flexion Pain not eased by flexion .
Tenderness
Most prominent site: None
Spinous process S-l joint right S-I joint left Paravertebral muscles right Paravertebral muscles left Greater trochanter Other (e.g. donor site)
Secondary site: None Spinous process S-I joint right S-I joint left Left buttock
Paravertebral muscles right Paravertebral muscles left Other
Spinous Process tenderness:
None 99 . Ll L2 L3 L4 L5 SI
Superficial A combination variable ('Tender') was for purpose of analysis, coded thus: 1 normal - no tenderness 2:1 place tender 3:2 places tender
Gaenslen test (sacro-iliac stress):
Normal Right positive Left positive Productive of marked back pain
Lower limbs
Length of legs: Equal Right shorter by 1-5 cms Left shorter by 1-5 cms
Peripheral pulses: Normal Marked decreased right 100.
Hips: Normal 98%
Right abnormal (possible O.A.) 2%
Knees: Normal 84%
Right abnormal 7%
Left abnormal 6%
Both abnormal 3%
In most cases abnormality consisted of a menis•
cectomy scar or degenerative change.
Ankles: Normal 94% Right abnormal 2% Left abnormal 2% Both abnormal 2%
Right foot: Normal 90% Hallux valgus 1% Claw or hammer toes +_ calluses 2% Abnormality of arch § hammer toes 1% Other (e.g. scars, absent digits) 6%
Left foot: Normal 88% Abnormality of arch 2% Hallux valgus 1%
Claw or hammer toes +_ calluses 2% Abnormality of arch § hammer toes 1% 101.
Other
Neurological examination
Straight leg raising pain:
None 42%
Right 0-30 degrees 2%
Right 31-60 degrees 3% Right 61-90 degrees 9%
Left 0-30 degrees 2%
Left 31-60 degrees 3% Left 61-90 degrees 7% Both legs 0-30 degrees 6%
Both legs 31-60 degrees 14% Both legs 61-90 degrees 12%
Bowstring sign: Pressure over the taut popliteal nerve. Negative bilaterally Positive left 2% Positive right 9% Positive bilaterally 3%
Muscle wasting: None 74% Asymmetry of thigh or calf (2 cms), wasting of anterior calf muscles or ext. dig. brevis 26% 102.
Abdominal muscle power: (A) ability to lift straight legs 10 cms off the table.
Present 94% Absent 6% Abdominal muscle power:
(B) ability to lift upper body off the table with legs secured.
Normal - fairly easily 56% With difficulty - but all the way 17% Moderate difficulty - only part way 22% Marked difficulty - only just able to move 5%
Back muscle power: ability to lift buttock off the table when supine. Normally and easily 59% Remains extended with some difficulty 23% Moderate difficulty - cannot sustain it 4% Marked difficulty - unable to raise buttocks 14%
Lower limb muscle power: this was recorded in the standard fashion
(grades 0-5)
for each of the following muscle groups:
Hip flexors, extensors, abductors and adductors; 103.
knee extensors and flexors; foot dorsiflexors, 0 plantar flexors, evertors; great toe extensors
0 and flexors. Results for each group were coded:
Left Right
0 0 Grade 5
1 1 Grade 4
2 2 Grade 3
3 3 Grade 2
4 4 Grade 1 5 5 No function A compound index for analyses (LEPGOW) was derived by summating the coded scores for each of 22 categories. These categories represent the 11 different muscle groups (hip abductors, adductors, flexors, extensors, etc.) conventionally examined and recorded bilaterally (Appendix l ). No effort was made to record the examiner's opinion of the nature of weakness, but the impression was gained that organic weakness was always well localised. Results:
Normal 70% 1 11% 2 3% 0 3 4%
5 3%
6 1% 104 .
7 2%
8 2% 11 1%
19 1%
20 11 24 1%
.Deep tendon reflex (knee): the more severe change was scored.
Normal 87% Heft decreased 21 Left absent 2% Both increased 1% Both decreased 7% Both absent 1%
Deep tendon reflex (ankle): the more severe change was scored.
Normal 50% Right decreased 5% Right absent 8% Left decreased 2% Left absent 15% Both decreased 7% Both absent 13%
Plantar reflex: Normal 98% 105.
Abdominal reflex: Absent both sides Abnormal because of local disease
Cremaster reflex: Normal
Absent right
Absent both sides
Abnormal because of local disease
Sensation (right), level of impairment:
None
L4 dermatome L5 dermatome 51 dermatome 52 dermatome More than 1 root involved Peripheral nerve loss
Sensation (left), level of impairment:
None L4 dermatome L5 dermatome SI dermatome a More than 1 root Peripheral nerve loss Combination of above 106.
A combination index (LOSSRL) was made to in• dicate the presence or absence of sensory loss: Normal 52% Abnormal 48%
EVALUATION OF AND B¥ THE PATIENT
Motivation for surgery: (as remembered by the patient).
Patient initially refused surgery 1% Surgeon suggested it, after con• siderable conservative therapy 76% Surgeon suggested it, after little conservative therapy 23%
Patient's opinion of last operation: Permanent definite improvement . 54% Permanent partial improvement 23% No improvement 7% Temporary improvement <2 years 7% Some worsening 2% Definitely worse 5% Other (e.g. had no complaint prior to surgery) 2%
Under the same circumstances: (the patient would).
Accept surgery again 78% 107.
Refuse surgery again 17%
Undecided 5 %
Reasons for surgery: (as understood by the patient)
Purely on surgeon's recommendation 2%
To relieve pain 88%
To prevent further trouble 1%
To improve weakness 4%
To improve back function 1%
Other 4%
Examiner's opinion: Patient definitely improved 58% Patient partially improved 19% Worsening - progressive disc disease 5% Worsening - emotional disease 2% Temporary improvement - now worsening 6% The same, or qualified 10%
PSYCHOLOGICAL PATIENT EVALUATION BY THE ORTHOPEDIC EXAMINER.
All patients were evaluated on ten psychological measures to assess the usefulness and significance of such measures by an orthopedic examiner. Scores of 1 through 7 were assigned for each; the scores are listed in Table 6 . 108.
COLD TOLERANCE.TEST The median time for performance of this test was 135 seconds. 5.*5% reached the cutoff time of 180 seconds and, at the average temperature of the water of 4°C, all these felt that they could have kept their hand immersed for a longer period.
Handedness: Right handed 92%
Left handed 8%
INTERPRETATION OF THE X-RAYS
Number of lumbar vertebrae:
4 distinct lumbar vertebrae 2% 5 distinct lumbar vertebrae 88% 6 distinct lumbar vertebrae 4% Incomplete transitional 6th vertebra 6%
Sacral anomalies: Normal 71% Congenital (e.g. spina bifida, transitional L5) 15% Acquired (e.g. sacroiliac osteoarthritis) 14%
Separate facet epiphysis: None 97%
Ll 2% L5 1% 109 .
Scoliosis: None 99%
10-20 degrees 1%
Spondylolysis: None 93% L4 4% L5 3% Of these seven subjects, two had spondylolysis
of L5 and fusion at the L4S1 level, three others with L4S1 fusion had spondylolysis at the L4 level; of two with L5S1 fusion, one had spondy• lolysis at the L4, one at the L5 level. Of those with spondylolysis above the fusion level, three were bilateral, two unilateral in appearance.
Spondylolisthesis: None 89% Grade 1 10%
Grade 2 1%
Osteoporosis: this was graded visually. None seen 88% Grade 1 5% Grade 2 5% Grade 3 2%
Old fracture: (of body or transverse process).
None seen 89% 110.
Present 11%
Myelogram dye: None seen 42%
Few drops 53% Moderate amount 5%
Evidence of laminectomy: (with visible evidence of bone removal)
None seen 90%
L4 2% L5 4% Combination 4%
Type of fusion: Posterior bone graft only 22%
Boucher type 48% Posterolateral 6% Apophyseal screws and bone graft 7% Anterior interbody 2% Other types (Wilson plates, posterior interbody) 4%
Combinations 11%
Level of fusion: L5-S1 40% L4-S1 46% L3-S1 4% L4-5 7% L3-4 1% Other (e.g. L3-4 and L5-S1) 2% 111.
Solidity of fusion: Solid fusion 67%
Pseudoarthrosis (at either level if 2
are fused) 33%
Criteria used in assessment of fusion required
at least two of: visible defect in bone mass,
persistent posterior (apophyseal) joint space,
motion on bending films in one or both planes
(in the absence of rotation).
Number of screws: None 34%
1 1% 2 41% 3 6% 4 16% 5 1% 7 1%
Abnormality of screws:
No screws 34% Normal screws 50% Bent 14% Broken 2%
Schmorl's nodes: None seen 89%
One site 5%
More than one site 6% 112.
Knutsson's sign: (the "vacuum" phenomenon)
Not seen
L5S1
L4 5
Posterior joint degeneration:
None seen
One level, unilateral
One level, bilateral
More than one level
Traction spurs of anterior longitudinal ligament None Present at one site More than one site
Osteophytes: (excepting above)
None One site More than one site
Ligamentous calcification: None Localised one level More than one level
Kissing vertebral spines:
None 113.
One level 32% Two levels 9%
MEASUREMENT ON THE X-RAYS.
Lumbosacral angle: the angle formed between the axes of the L5 and
SI vertebral bodies ranged from 127 to 173 de•
grees. The mean was 143.1 degrees (+_ 8.84).
Measurements were made at as many levels as possible of the following a variables: (Figure 3) Vertebral body height (front and back) Intervertebral disc height (front and back) Posterior joint subluxation above the joint-body line. Retrospondylolisthesis of each vertebral body on the next lower. Interpedicular distance. Sagittal diameter of canal. Each was measured to the nearest millimetre. A mean value for each subject was also derived, using only paired anterior and posterior values in the case of the vertebral body and intervertebral disc heights. Values were also obtained for the purposes of correlation only of disc height, retrospondylolisthesis and posterior joint subluxation at the level above the fusion. These values, together with the number of complete observations possible, are listed in Tables 7 through 12. 114.
PSYCHOLOGICAL RESULTS
The psychological results will be given in two groups, consisting of the descriptive data obtained in the structured interview and the objective psychometric test data. Full details and analysis are pre• sented elsewhere279.
DESCRIPTIVE DATA:
Position in birth order: obtained in absolute terms, to be related
to the number of siblings. Ranged as follows. First child 23% Second 29% Third 18% Fourth 9% Fifth 7% Sixth 5% Seventh • 4% Eighth 1% Ninth 3% Eleventh 1%
Province of birth: Not Canada 28%
British Columbia 31%
Alberta 10% 115. Saskatchewan Manitoba Ontario Quebec
New Brunswick Nova Scotia
Size of community during childhood years:
< 500 500-1,000 1,000-2,500 2,500-5,000 5,000-10,000 10,000-25,000 25,000-100,000 > 100,000
Unable to estimate :many moves
Father's occupation: No father Farmer Small business (owned) Large business (owned) Professional Semiprofe s s i onal (e.g. te acher, accountant) 116.
Blue-collar (clerk, agent, etc) 3%
Minor supervisor 7%
Major supervisor 4%
Service employee 7%
Labour 30%
Unemployed 1%
Other 3%
Parents religiousness: None 26% Very 18%
Moderately 27% A little 12% One parent not, one quite religious 13% Very moral, not religious (if given spontaneously) 4%
Parents compatibility: rated on a seven-point continuum, scores 0-70 ("99" = no score) Range" 0-99
Mean 40.9 S.D. 21.13
Childhood happiness: rated on a seven-point continuum, scored 0-70 ("99" = no score)
Range 5-70 117.
Mean 48.7
S.D. 16.45
Any of family "sickly": (up to 3 scored) A B C
None 58% 90% 94%
Father 14% 4% 1%
Mother 14% 4% •tn
Samed sexed sibling 8% 0% 0%
Opposite sexed sibling 5% 1% 4% Uncle, aunt 1% 1% 0%
Age of leaving home permanently:
Range 13-39 years
Mean 19 years
Grade School - number of years completed:
Range 0-13 Mean 8- 83
University - number of years:
None 95%
1- 6 years 5%
Vocational School - number of months:
None 65%
2- 40 months 35% Overall mean 3.2 months 118.
Years of apprenticeship: None 68%
1-6 years 321 Overall mean 1.12 years
School subjects: Favorite Most Hated Cannot answer 11% 10%
Mathematics 39% 21%
A science 9% 7% English or a language 13% 37% History/geography 13% 12% Shopwork, agriculture,
home economics 5% 0%
Sports 3% 1 % Art, drama, music 6% 9% Other 1% 3%
Religious change recently: Never religious 37% Always religious 25% Have changed to more religious 8% Have changed to less religious 27% Remain religious, have changed faiths 3%
Armed Forces Service: None 59% WW 2 (did not see battle) 14%
WW 2 (saw battle ) 13% 119.
Korea (saw battle) Peacetime f.crcesonly
Additional marital history: A Nothing to add 77%
One divorce 14%
Two divorces 1% Widowed once or more 2%
One separation 3% One past common-law wife 3% Two or more past common-law
wives 0%
Status of present marital relationship: There is none Ready to break up Would break up except for children Stormy but will remain intact About average Above average Superb
Sex life: Not exposed to one Little - spouse frigid or impotent Little - because of subject's back Little - because of subject's other troubles 120. Moderate - mutual 4%
Moderate - spouse's lack of interest 7%
Moderate - spouse's other troubles 6%
Moderate - subject's lack of interest 1% Moderate - subject's back 10%
Moderate - subject's other troubles 2% All is well 40%
Number of children now at home: 0 34% 1 17% 2 23%
3 17% 4 7% 5 2% Mean 1.5
Also supported by patient: None 90% Parent or grandparent 4%
Parent or grandparent of spouse 1% Unrelated child or adult 5%
Ownership of home or apartment:
None 25% 121.
Yes, large mortgage > $10,000 211
Yes, moderate mortgage $5-10,000 8%
Yes, small mortgage < $5,000 14%
Yes 32%
Was a home ever owned? No 87%
Yes - given up for financial reasons 5% Yes - given up for other difficulties 3%
Yes - given up for convenience 4% Other 1%
Mean Family income in $100's : (gross monthly)
Range 1-40 Mean 8-52 Median 8
Sources of income: A B C No additional source - 26% 74% Business ownership 9% 3% 3%
Investments 0% 7% 1% Patient works 79% 9% 0%
Spouse works 6% 29% 4% Pension 0% 0% 3%
Children 1% 2% 0%
Welfare 1% 2% 0% 122. Insight: Does the subject think that personality or
psychological status can have a bearing on the existence of on the experience of a back problem?
No 24% Yes, a little 7% Yes, a moderate amount 4% Yes, quite a bit 8% Not for self, but for other quite . a bit 10% Not for self, but for others a lot 33% Will not give a direct answer 14%
Number of times psychiatric attention has been received: 0 82%
1 10% 2 1% 3 2% 4 3% 5 1% 7 1%
Psychiatric attention first received: Range 0-25 years ago.
Psychiatric attention last received : Range 0-25 years ago. 123.
Psychiatric attention for rest of family:
None 76% Parent 4% Sibling 6%
Spouse 9%
Offspring 4% Other 1%
PSYCHOMETRIC DATA.
INTELLIGENCE: The Cattell Culture-Free Test was used to avoid the bias normally introduced by testing mixed ethnic groups with a test including verbal performance, such as the Wechsler. The mean I.Q. was 83.18.
PERSONALITY: this was assessed using four test: the Minnesota Multiphasic Personality Inventory, the California Personality Inven• tory, the Beck Inventory of Depression and the Kilpatrick-Cantril Self-Anchoring Scale. The means on the appropriate scales are as follows: (see Appendix45-6 for explanation).
Scale Overall mean
MMPI L 50.12 F 59.18 K 49.55 1 (Hs) 66.27 2 (D) 65.08 3 Hy) 63.79 124. Scale Overall mean MMPI 4 (Pd) 57.70 5 (Mf) 56.70 6 (Pa) 56.10 7 (Pt) 58.44 8 (Sc) 58.15 9 (Ma) 59.32 Si 53.16 Es 48.64 Lb 59.01 Taylor 18.46
CPI 1 Do 46.07 2 Cs 45.76 3 Sy 47.20 4 Sp 49.38 5 Sa 49.71 6 Wb 43.62 7 Re 43.74 8 So 44.66 9 Sc 48.67 10 To 45.06 11 Gi 47.79 12 Cm 50.67 13 Ac 43.58 14 Ai 46.29 15 le 42.48 16 Py 50.82 17 Fx 44.55 18 Fe 51.78 Beck 8.04 Kilpatrick-Cantril
Past 59.80 Present 62.57 Future 75.27 125.
PRODUCTION OF THE "SUCCESS" FACTOR.
No single measure was found to act as an index of successful function of the patient at the time of examination, and the success of a specific fusion operation cannot be rated by merely recording the overall impression of the examiner at the single follow up visit. The reasons that the patient initially sought medical help for. his back: the reasons for which the fusion operation was performed, are of paramount importance. The success of any form of medical treatment requires the complete rehabilitation of the patient with return to his normal activities, whether at work or during leisure, so that the usual responsibilities of breadwinner, spouse or parent can be resumed.
From experience in the pilot study and a study of the appropriate portion of the literature, a list of features was drawn up to be re• presented in the derivation of a success index. The twelve features were:
1) Pain 2) Work
3) Finances 4) Household care 5) Self care 6) Flexibility of the body 126.
7) Mobility of self 8) Sleep impairment
9) Sex life
10) Social life
11) General quality of life 12) Retrospective opinion of surgery
The features were constituted by twenty variables, which are described in the following pages. Each variable encompasses some aspect of the patient's function which may show impairment due to the low back problem. Overall, they describe pain, employment, family finance, the activities of daily living, quality of life and the patient's own..view of his surgery.
To derive a patient success score, factor analysis was performed. The statistical process of factor analysis assumes that the inter- correlations of these twenty variables can be explained by the fact that each is an indirect measure of several factors, themselves un• related (orthogonal : non-correlating). A theoretical factor score is derived for each patient based on the correlation coefficients between the variables. The "success" factor was taken to be the first on the unrotated matrix, representing the most important source of total variance of the input dat* (40.1%). The computer program "UBC
FAN" was used10'', developed from the UCLA BMD x 72 program. The patient scores on the first factor, "successV were used for sub• sequent correlations. 127. With the descriptions of the variables, the factor loading (F.L.) of each is given, which is the correlation coefficient of that variable with the factor "success". Percentages are the frequencies or number of subjects falling into each category. The variable name is as used in analyses.
1) Pain
a) "Severity" - severity of pain FL = - 0.8078
1. No pain 17% 2. Mild pain, not a problem 24%
3. Pain annoying, but forgotten during activity 11%
4. Pain present even during activities 15% 5. Moderate pain, interferes with activities or sleep 24% 6. Pain prevents activity or sleep 9% 7. Severe pain, is immobilising 0% b) "Tender" - objective tenderness FL = - 0.6405 1. No tenderness 24% 2. Tender one site only - 30% 3. Significant tenderness at 2 distinct sites 46% c) "Coccyx" - pain in the tip of the tailbone FL = - 0.4107 1. None 66% 2. Occasionally 23% 3. Often 5% 4. Most of the time 6% 128. 2) Work
a) "Work" FL = - 0.6402 1. Continuing usual work without difficulty 341
2. Not working normally - back related 461
- ascribed to other causes 7% 3. Unable to work because of back 13%
b) "Loss" - time loss from work in last 2 years FL = - 0.6336
1. None 40% 2. Less than 1 week, not (1) 2%
3. Less than 1 month, not (2) 6%
4. Less than 2 months, not (3) 4% 5. Less than 4 months, not (4) 6% 6. Less than 6 months, not (5) 3% 7. Less than 1 year, not (6) 11% 8. Less than 18 months, not (7) 5% 9. Less than 2 years, not (8) 12% 10. Unemployed for this period 11%
3) Finances a) 'Nincome" - mean family income in $100 per month.FL = + 0.3994 Min $100 Max $4000 monthly Median $800 Mean $ 851 b) "Money" - financial circumstances FL = - 0.2219 1. I am comfortably off financially 13% 129.
2. I have no debts, but would like to have more money in reserve 331 3. I have some small debts 45%
4. I am in a fairly serious financial position 9%
4) Household care
"Chores" - mark the most difficult that you can
manage FL = + 0.3997 1. Cannot manage anything 4% 2. Washing up 3%
3. Cooking 1% 4. Cleaning kitchen 0% 5. Cleaning and tidying house 3% 6. Making beds 8% 7. Washing or polishing floors 4% 8. Carrying a heavy object such as a suitcase 18% 9. Moving heavy furniture 7% 10. Doing heavy digging in the garden or similar 52%
5) Self care "Independ" - caring for yourself - mark the most you can do FL = - 0.5321
1. Unable to look after myself 0% 2. I can feed and wash myself but need help dressing 0%
3. I am able to do the above, I can cut my own toenails 16% 130.
4. I can dress myself completely but need help with
some things 131
5. I am totally independent 71%'0
6) Flexibility of the body
a) "Chair" - sitting, getting up FL - - 0.7518
1. Neither of these gives me any discomfort 49% 2. I can sit down but getting up from the sitting position may hurt 25% Getting up does not hurt but actually sitting
may hurt 11% 3. Both sitting down and getting up may hurt 15% 4. Because of difficulty I need help with sitting down and rising from a chair 0% b) "Floor" - picking things up off the floor FL = - 0.8120 1. I can pick things up off the floor without difficulty 54% 2. Bending hurts, but I can straighten up without difficulty 8% I can get down to pick something up but straightening hurts 17% 3. Both bending and straightening up hurts 17% 4. Because of discomfort I just cannot pick things off the floor 4% 131. 7) Mobility of self
a) "Mobile" - walking. FL = - 0.7400
1. No limit to walking 53%
2. I have to stop after about half a mile because of discomfort 21%
3. I can only walk 2-3 blocks before I must rest 17%
4. I can only walk very short distances, but can manage stairs and get around the house 8%
5. I cannot manage stairs 1% 6. I need help to move even in the house 0%
7. I have to use a wheelchair 0% b) "Transpor" - riding in a car or bus FL = - 0.7346 1. No back-related difficulty in getting in or out or riding 48% 2. Difficulty with mounting or dismounting or 12% travelling is uncomfortable 27% 3. Both the above (2) 9% I avoid car or bus travel whenever possible because
of difficulty 4%
8) Sleep "Sleep" FL = - 0.7092
1. Normal sleep habits 48%
Sleep impaired due to other illness in self or family 2% 132.
2. Difficulty in getting to sleep and/or early waking
due to discomfort 42%
Sleep impairment for reasons unknown 6%
9) Sex Life
a) "Sex" FI = - 0.6490 1. Normal - no problem at all 59% Other difficulty in either partner 3%
2. Back pain necessitates the use of certain positions or 7% frequency is greatly limited by back pain 14%
3. Both of the above are true 17% b) "Slife" - absolute "quantity" of sex FI = + 0.3078 1. No sex life 11% 2. Little, for all reasons 19% 3. Moderate amount 30% 4. A lot 40%
10) Social Life "Social" - going out with friends; to parties or
dances, etc. FI, = - 0.8305 1. No limitation for any reason 46% I have had to change activities for some other reason 2% 2. No change in the type of activities, but less often because of pain 13% I have had to change to easier activities because of back pain 28% 133.
3. I can do very little because of pain 11%
11) General quality of life
•"Life" FL = - 0.7017
1. I enjoy life 44% My enjoyment of life is more affected by other problems 1%
2. I enjoy life, but quite a bit less than I did before this back trouble arose 8%
3. Life is only just tolerable because of this back
(or leg) discomfort 8% 4. I have even thought of suicide because of this problem 0%
12) Retrospective opinion of surgery
a) "Opinion" - patient's opinion of surgery (last operation only) FL = - 0.7598 1. Permanent definite improvement 54% 2. Permanent partial improvement 23% 3. Temporary improvement, no improvement, or worse 23% b) "Again" - under the same circumstances, the
patient would now: FL = - 0.5016 1. Accept surgery again 78% 2. Undecided 5% 3. Refuse surgery again 17% 134.
It should be noted that: The variables differ in some instances from those in the appen• dices to improve the ordinal distribution.
No weighting coefficients were applied to variables, and weighting of the 12 features is only by the number of variables delineating that feature.
Zero responses to certain variables reflect their design to allow for more severe disability, as was found in the patient's re• membered state one month prior to their fusion (not used here).
The factor scores of "success" obtained thus were standardised, having a mean value of zero and unit standard deviation. The factor scores were used to assess overall response, for direct comparison with certain features, as the major independent variable in a mul• tiple correlation matrix and for subsequent assessment of success- related factors. "Success" is a hybrid factor. The higher the score for an in• dividual, the more satisfactory is his overall function to him, and this is of much greater significance than the opinion of the ortho• pedic surgeon. Thus, those variables showing a high correlation with "success" are those variables which the successful surgeon will seek to manipulate in the optimal manner. In a prospective study of fusion, regression analysis on "success" as the dependent variable will en• able scientific improvement in the application of the operation. 135.
PERFORMANCE OF MULTIPLE CORRELATIONS AND THEIR EVALUATION.
THE CORRELATION MATRIX
The "success" factor scores and 239 other variables were used as input data for the program "UBC C0RR", providing coefficients of correlation and probability values for significance for each pairwise correlation of all variables. To more easily examine the output, the correlations were coded by significance thus:
'invalid' 1 = p < .01 2 = p < .001 3 = p < .0001 Invalidity implies an insufficient cell frequency for the appli• cation of the chi-square method of significance analysis (in the correlation of a nominal variable with other nominal or ordinal data). In general, variables were selected or recombined where possible to avoid this problem: this was not possible with certain variables. The resultant matrix is seen in Table 13 in greatly reduced form. The va• riables are listed in Appendix 1. The experimentwise error rate may become high when such multiple comparisons are made: the number of chance occurrences of "significance" being found can be calculated (probability p for not making a g-error commission = (l-a)c, where a = error rate, for example .01, c = 136. number of comparisons made). However, the use of such a formula is difficult; an approximation can be made by considering that "signif• icance" may occur once in 1000 times if p = .01, hence in 28,920 pairwise correlations if p = .01, 29 "significant" correlations might occur by chance. By rejecting all correlations failing to reach the significance level p < .01, the number of falsely 'significant' re• sults is reduced.
With this multivariate analysis (evaluation of many variables simultaneously) it is possible to do one of two things: either to perform factor analyses to simplify the concepts, with certain hypo• theses in mind, or to isolate small sections of the overall correla• tion matrix to again simplify the problem. Both techniques are used here.
SUCCESS: DERIVATION
The basic purpose of the study being to determine the dimensions, or associated factors of success, the initial concern was to determine the correlations of the "success" index. Fifty-five of the variables not used in the derivation of "success" were found to correlate significantly (p < .01) with the "success" score. To simplify the conceptualisation of the roles each played and to determine the importance of their contribution to success, factor analysis was again performed (using U.B.C. FAN) on the basis of the intercorrelations of these 55 variables. 137.
Table 14 lists the 55 variables used and the factor loadings. The variables are grouped according to their contributions to the respective factors (i.e. the first group of variables has the highest loadings on factor 1, the second group or cluster on factor 2, etc.). The factor loadings are also simplified by giving the first two fig• ures of the coefficient, rounded off. Here 100 would represent per• fect correlation, 00 no correlation, and -100 perfect inverse corre• lation. Finally, the correlation coefficients of factors against success are also shown, along the bottom of the table.
The factors are identified by representation and placed in order according to their correlations with the "success" index in Table 15. These factors are, of course, orthogonal: they show absolutely no correlation with each other, and do not overlap. Being totally in• dependent, each independently accounts for a percentage of the va• riance of the "success" scores, and this percentage can be summated. (The percentage variance accounted for is found by calculating the square of the correlation coefficient X 100.) The total variance of "success" accounted for by the eight significantly-correlating fac• tors ( p < .05) amounts to 79.961. The interpretation placed on this is that if the "success" index is taken to represent the follow up functional status of the patient, this actual function may be dependent on many things, eight of which are represented by the significantly-correlating factors, each totally independent of each other. The optimum result in an individual will 138. be dependent to a large extent on the optimal representation of these factors (accounting for 79.96% of the variance) with the additional influence of the other factors shown (cumulative total of 89.11% of trie variance) and others not yet identified.
SUCCESS: ANALYSIS
As mentioned before (p 59) the determination of success of fusion operations has always been performed in terms of one or two
16 30 simpl• i e variables• ui , particularl«-• -i i y pseudoarthrosiA *T, •s > ' > '34 , '108 , ' 153',
207, 211, 215, 216, 252, 258, 285 n., , . ,. , , although some studies have used predominantly clinical considerations23'41 ' 46> 60' 65' 140' 194. Subsequently, it is conventional to place the patients in discrimina• ting categories and then to compare the groups, much as has been done here with the pilot study. However, the derivation of a numerical index of success has not been used before, to the author's knowledge, except by NASHOLD and 195 196 HRUBEC ' , in a 20 year follow up of patients with herniated nucleus pulposus. Their method was identical to the one used here in the main phase of the study (which was developed independently) except for the actual variables used. The loadings of their ''dis• ability index' are shown in Table (rounded off to 2 figures as in this work); this factor only accounted for 23.1% of the variance of the input dat<&. This compares well with the figure of 40.3% ob• tained in this study. 139.
It will be noted that they attached less importance to the pa• tient's subjective complaints. In their study, the disability index was used as the dependent variable in a regression analysis to deter• mine the relative importance of the variables recorded at the initial hospitalisation of the patients (with the data available, the only factors clearly emerging as predictors of subsequent disability were age at the initial hospitalisation and chronicity of the disease at that time).
Regression aanalysis has been found of assistance here in the interpretation of the psychological results but in the clinical set• ting will be of more use in a prospective study. It is not of statistical value to place the patients in discrete categories entitled, for example, 'good', 'fair', and 'poor' if the overall relationships can be better assessed by correlation or factor analysis, for example. Graphically, grouping may make interpretation easier, however (see psychological profiles by quartile grouping, Table if,). These methods, then, have allowed the establishment of a multi• factorial etiology of the low back pain syndrome in this experimental setting and the identification of the proportional importance of the factors. They have not, in this study, established a causal role for these factors, merely an associative role, but clearly indicate:' their suitability for application to a prospective study for causal determination. 140. ASSESSMENT OF EXAMINATION METHODS - WHAT DO THEY INDICATE?
Table 18' shows a correlation matrix of certain orthopaedic exam• ination results with the success index and certain psychological and radiological variables. It is not possible to show the exact signif• icance of each number, which represents the first two figures (rounded off) of the correlation coefficient. All coefficients shown are sig• nificant at the p < .05 level, and an approximate guide would be that values shown over thirty-five are significant at the p < .01 level, over forty-five at the p < .001 level and over sixty at the p < .0001 level (it must be stressed that these are only very rough approxima• tions) Underlining indicates an inverse correlation between the two variables as recorded (see appendix 1). This section is based on the table.
"Success" (the first column) can be looked at again in terms of the factor analysis results (p 137. ) which explained the inter- correlations found between the "success"-correlated variables. The appropriate correlation coefficients in the first column again high• light the associated factors: numbers of operations and levels fused, intelligence versus neuroticism, lumbar degeneration and limitation of mobility, pain tolerance, muscle fitness and neurological deficits. "Severity" (of pain), as a constituent of "success" has a high correlation with it and is included for additional comparison with certain variables.
The purpose of assessment of range of motion is primarily 141.
orthopaedic: to provide information on the underlying structural pa• thology so that appropriate therapeutic measures can be undertaken. It is implied that these measures are objective and representative of disease processes affecting, in this case, the lumbar spine. If this is so, it should be possible to appropriately interpret the correlations of these variables as relating to organic pathology: if not, usage of these methods should be re-evaluated.
In this study, the standard methods of recording finger-tip reach (for forward and lateral flexion) and of visually assessing extension were used: the degree of pain on active and passive ex• tension were likewise recorded. Only one truly objective method was used - measurement of the cervico-sacral increment (p 96. ) and it is apparent that this could be replaced by better methods.
Likewise, muscle tone and power were assessed by standard methods (p 102. and Appendix 1). Deep tendon reflex abnormality and loss of sensation were recorded (p 104. and Appendix 1) and the time of immersion in the Cold Tolerance Test (Appendix 3). Ideally, each test should be specific, with minimal correlation with methods supposedly measuring another parameter. The inter- correlations will be described under several headings.
MECHANICAL LIMITATION: Measurements of organic range of motion which are demonstrating mechanical limitation should show significant
correlation with age, degree of degeneration evidenced radiologically
and the number of levels fused. "LUMFLEX" (cervicosacpal increment 142.
limitation), "LUMEXT" (visually-assessed limitation of extension) and RLFLEX" (combined limitation of right and left lateral flexion by finger tip reach) show correlations with age, unlike "FLEXTWO" (lim• itation of forward finger tip reach), "PAINEXT" (pain reported on active extension) or "HYPEREXT" (degree of pain on passive hyperex- tension). These latter measurements show higher correlations with "success" so that it might be supposed that degenerative changes at the lumbar level are responsible.
However, examination of the correlations with "DEGEN" (degree of posterior joint degeneration), "SPURS" (number of sites traction spurs of the anterior longitudinal ligament are seen), "OSTEOPHY" (degree of osteophyte formation), "BAASTRUP" (degree of pseudoarthro• sis formation between adjacent spinous processes), "DISCMEAN" (mean height of measurable disc spaces), "RETROAVG" (mean retrospondylo- listhesis of one vertebra on that below) and "LUXMEAN" (mean value of posterior joint subluxation in the lumbar spine) shows only "LUMEXT" and "RLFLEX" to be indicators of disc degeneration. The number of segments fused ("LEVEL A") is only seen to corre• late significantly with limitation of extension and pain on passive hyperextension and not with the other range of motion measures.
PAIN TOLERANCE AND TENDERNESS: Hyperextension is seen to be corre•
lated with pain tolerance ("CTT") as is "PVTONE" (degree of paraver•
tebral muscle spasm), but the measures of range of motion do not 143. correlate thus with pain tolerance, as shown by the cold tolerance test.
Tenderness ("TENDER" - number of tender sites in the low back) is apparently a separate phenomenon and does not correlate with true pain tolerance. All the measures of motion except the cervico-sacral increment correlate with "TENDER" and similarly with "GAENSLEN", sup• posedly a measure of sacroiliac pathology which correlates, rather surprisingly, with ""RETROAVG" and "RETRONEX" (the mean amount of retrospondylolistehesis at all levels, and that occurring at the level above the fusion). The same measures also correlate with "PVTONE".
PSYCHOLOGICAL ABNORMALITY: The psychological measures used in this matrix are "CAT IQ" (IQ as determined using the Cattell test),
"BECK" (the score on the Beck Inventory of Depression), "MMPIHS"
(the T-score on the hypochondriasis scale of the MMPI) and "TAYLOR"
(the score on the Taylor Anxiety Scale). In this setting an inverse relationship of intelligence to depression and hypochondriasis is seen.
Intelligence correlates inversely with all measures of limita• tion of motion except the cervico-sacral increment. It is also of interest to note that it correlates inversely with certain radiolog• ical measures of degeneration, probably due to occupational factors, the manual laborer showing more degenerative changes.
The measures of depression, hypochondriasis and anxiety all 144. correlate with limitation of range of motion (except cervico-sacral increment), pressure tenderness, hyperextension tenderness, Gaenslen tenderness, paravertebral muscle tone, also the number of levels fused ("LEVEL A") and degeneration as osteophyte formation and spinous process pseudoarthrosis ("BAASTRUP"). This may be partly age-related and partly a result of the fusion; however, as there is no correlation between the number of levels fused and the incidence of kissing spines the causal sequence could be hypothesised psychological abnormality - muscle tension - abnormal motion - Baastrup phenomenon. Retrospecti• vely, only hypothesis is possible.
A further possible reason for the psychological correlations is involvement of other joints (e.g. the hip joint) by the motivational changes.
NEUROLOGICAL DEFICIT: This was 'measured' as muscle weakness
("ABDPOW B", "BACKPOW", LEGPOW"), straight leg raising limitation by pain ("SLR"), presence of muscle wasting ("WASTE"), deep tendon re• flex impairment at knee or ankle ("DTRKNEE" and"DTRANK") and presence of sensory loss ("LOSSRL") for the purposes of correlation.
Again, the picture is confusing: the measures of trunk muscle power impairment correlate highly with "success" (inversely), in• versely with intelligence, positively with psychological abnormalities
(especially "BACKPOW") and limitation of motion except the cervico- sacral increment, which correlates only with abdominal power. "BACK•
POW also correlates inversely with pain tolerance ("CTT"). There is 145. no age correlation.
It would thus seem that these are two hybrid measures - back muscle weakness, is a function of emotion and pain tolerance, among other things, perhaps abdominal power is less affected by these things and enters more into mobility and suppleness as an organic phenomenon.
Straight leg raising limitation by pain also seems to be a hetero• geneous measure, showing correlations with pain tolerance, tenderness, the psychological phenomena and operative history. Also significant (p < .001) but not on this matrix is the correlation (.66) of "SLR" with "BOW" (presence of a positive bowstring sign) Straight leg raising limitation does not correlate significantly with impairment of the deep tendon reflexes.
Muscle wasting ("WASTE") also correlates with a positive bow• string sign (coefficient .47, p < .05) and with narrowing of the disc above the level of fusion ("DISCNEXT"). The inverse correlation with the presence of myelographic contrast medium on x-ray is puzzling unless it is rationalized that a patient who has had a myelogram will have had accurate localisation and excision of a herniated disc - a known requirement for good result of discectomy. (Lower limb weakness is also correlated with the presence of myelogram dye and not to the number of operations - the dye itself may be a causative factor in lower limb neurological abnormalities.) The deep tendon reflexes are of interest: with no relationship to intelligence, only the ankle jerk shows correlation with "success", 146. the measures of psychological abnormality, degenerative changes and
(slightly) with age (coefficient -.22, p < .1). Both deep tendon re• flexes bear a relationship to the number of fusions and overall num• ber of operations. It seems again that both structural and psycho• logical features are represented by these measures, particularly by the ankle reflex, while loss of sensation shows a similar pattern of correlation:
EXAMINER ERROR: This is obviously a major potential source of variance in the recording of any of the orthopaedic measures and yet it should be the easiest to eliminate- It is not possible to assess the observer error from the available data.
Within the limits of a retrospective study, it is again possible to say that the orthopaedic measurements are incompletely objective, unstandardised measures of a number of factors. The methods should aim, as far as possible, for an effective assessment of actual motion of the lumbar spine only, reflecting the biomechanical influences of muscle fitness, suppleness and degree of degenerative changes. The influence of pain tolerance is unavoidable where limitation of the movement is by pain, and even psychological abnormality will be re• flected as this affects tenderness or is itself a product of pain, as will motivation influences such as high ego-strength, but it is essential to remove the error introduced by measurement across other joints and by permitting observer error to affect the measurements. 147.
Methods are available for this. Basic measurements have been 99 made by inserting Steinmann pins into the spinous process or by radiological methods3' ^. To avoid pain or unnecessary exposure! to radiation, special skin markers have been used, with a fair degree 263 of accuracy on correlation with radiographic measures However, the simplest methods are those evaluated by McRAE, MOLL 173 187 and WRIGHT, ' initially for evaluation of ankylosing spondy• litis. These involve measurement of the relative motion of two skin marks from neutral to the extremes in the particular plane measured, in a similar way to that described for the cervico-sacral increment except that the (minimal) influence of the thoracic spine can be ex• cluded (for flexion) by making the two skin marks respectively 10 cms. above and 5 cms. below the lumbosacral junction. Most importantly, these measurements on 237 subjects correlated well with radiological measurement of motion: Correlation P Flexion .97 < .001 Lateral flexion .79 < .001 Extension ' .75 < .01 173 Normal data for this sample were published . An increase in mean mobility was found from the 15-24 decade to the 25-34 decade with a later progressive decrease. These methods will be utilized on prospective work planned. 148.
THE RADIOLOGICAL VARIABLES - WHAT IMFORMATION DO THEY PROVIDE?
Table 19 shows a correlation matrix of the radiological variables with the "success" index, certain psychological and mechanical vari• ables. Again, it is not possible to show the exact significance of each number which represents the first two figures (rounded off) of the correlation coefficient. All coefficients shown are significant at the p < .05 level and on the average the higher the correlation coefficient, the smaller the chance probability of it occurring. Underlining indicates an inverse correlation between the two vari• ables as recorded. This section is based on the table; the variables are described in the section on the interpretation of the x-rays and in Appendix 1. The radiological variables used fall into several categories:
Dimensions of the lumbar spine and the spinal canal. This in• cludes the number of lumbar vertebrae "NUMBER", "BODYMEAN", "DISCMEAN", "LUXMEAN", IPEDMEAN" and others representing the appropriate dimen• sions described elsewhere. Developmental abnormalities. These include, for example, the presence of Schmorl's nodes ("SCHORL"), the presence or absence of the Knutsson phenomenon of the vacuum disc, spondylolysis and spon• dylolisthesis. It should be noted that spondylolisthesis was recorded 16 7 according to MEYERDING's classification of four grades . This is slightly less accurate than the measure of retrospondylolisthesis shown as "RETROAVG" which measures the forward or backward displace- 149. ment of the one vertebra on the vertebra below in millimeters.
Degenerative changes. Here we could place osteoporosis which was an approximate visual assessment of the degree of osteoporosis, and the degenerative changes of the lumbar spine including "DEGEN" (pos• terior joint degeneration at one or more sites), "SPURS" (the pres• ence of traction spurs of the anterior longitudinal ligament), "OSTEO-
PHY" (presence or absence of osteophyte at one or several sites), and
"BAASTRUP" (the presence, at one or more sites, of kissing vertebral spinous processes as evidenced by approximation and remolding of the spinous processes). Degenerative changes are also evidenced by the presence of posterior joint subluxation (quantitatively represented by "LUXMEAN" and "LUXNEXT") or retrospondylolisthesis (quantitatively represented by "RETROAVG" and "RETRONEX").
Operative phenomena. This includes the. number of levels fused
("LEVEL A"), the solidity of the fusion ("SOLID"), the number of screws used ("SCREWS") or the abnormalities of such screws ("SCREWED"). The presence or absence of myelographic contrast medium is recorded as
"DYE" and the observation of posterior arch bone removal was recorded as "LAMINECT".
The reader is referred to the table for the analysis of all correlations and those of note will be described below.
First, as before, "success" should be studied. The correlations may again be noted of "success" with severity of pain and the psycho• logical variables . "Success" shows an inverse correlation with 150. abnormality of stance, the number of levels fused, the presence of the Baastrup phenomenon and an increased lumbosacral angle ("LANGLE"). An inverse correlation with spondylolisthesis of .27 did not reach significance (p = .100), the trend indicates, however, the possibility of a better result in those with spondylolisthesis.
Severity of pain shows similar correlations with the abnormality of stance, number of levels fused and increased lumbosacral angle.
The correlated increase of lumbosacral angle is difficult to explain in terms of transitional lumbosacral vertebra when one considers the absence of correlation of "success" with the overall number of ver• tebrae .
Age, which correlates with depression ("BECK") but not anxiety ("TAYLOR"), correlates with abnormalities of stance in the form of a forward or lateral list and also with degenerative changes of all types as might be expected. Depression itself ("BECK"), with its demonstrated correlation with age, also shows correlations with the degenerative features and in addition with the Knutsson phenomenon. This correlation with the Khutsson phenomenon is even higher in the case of anxiety as evi• denced by the Taylor Anxiety Scale. As it was seen in only three patients it is not possible to make any firm conclusions about this correlation particularly in view of the lack of knowledge of its 142 structural nature Biomechanical influences on the x-ray picture are seen by the correlations of obesity ("FATFACT"), weight, stance, curve of the lumbosacral spine and tilt of the pelvis. Obesity shows interesting 151.
correlation with "LYSIS", of .84 (p < .01). In four of the patients this was shown to be a spondylolysis acquisita and it may be that obesity is an etiological factor in its production. Obesity also showed an inverse correlation with the visual assessment of osteo• porosis, presumably due to apparent increased density in the presence of increased subcutaneous fat. This points out the advantages of densitometry which, by its technique, allows for the compensation for
increased body weight. This correlation of osteoporosis with the num• ber of levels fused and the mean height of the disc again illustrates
the weakness of the method of visual assessment as has been described 1 79 by HURXTHAL, VOSE and DOTTER . It is planned to use densitometry in future assessment of osteoporosis. Abnormalities of stance are seen to be correlated with the num• ber of levels fused, and disc degeneration or narrowing as evidenced by "DISCMEAN' and "LUXMEAN". Abnormalities of lumbar curve showed a high correlation with the presence of Schmorl's nodes (which were seen in 11% of the sample). This high correlation may be due to a mechanical factor with the increased likelihood of central disc pro• trusion or maybe due to different centering of the x-ray beam in the patient with an abnormal lumbar curve with subsequent incorrect interpretation. Similarly, tilt of the pelvis correlated with an in• creased mean measurement of the posterior joint subluxation and this may also be due to incorrect centering or may in fact be true in• creased unilateral posterior joint subluxation, in compensation for 152. the pelvic tilt.
It is interesting to note that an increased number of lumbar vertebrae is associated with decreased evidence of posterior joint degeneration, a decreased mean sagittal canal diameter and increased retrospondylolisthesis at the level next above the fusion. The signif• icance of these findings is not known.
Noting the additional correlation of Schmorl's nodes with pseudo• arthrosis might indicate a form of tissue weakness which would cer• tainly fit in with its correlation with abnormalities of curve and increased spondylolysis. This can only be investigated by further prospective work.
Finally, the intercorrelations, as expected, of the various degenerative measures of the lumbar spine show only that the measures do not intercorrelate as well as might be expected, particularly with disc narrowing. However, subluxation of the posterior joints and in• creased retrospondylolisthesis do tend to intercorrelate. Techniques require improvement, particularly measurement of posterior joint sub• luxation which requires meticulous technique for accurate assessment.
It is difficult to quantify pathological changes in the lumbar spine but essential, in a study such as this, if variables are to be identified which will discriminate between individuals or groups of patients in the clinical setting. Criteria for discrimination in re• cording must be clear and objective if they are to become generally useful. Yet this is still not possible, for example, in determination 153. of the position of the posterior wall of the vertebral canal when measuring the sagittal diameter at the fusion level, and the im• portance of variations in such measurements may remain concealed until the measurements themselves are made easier. 154.
DISCUSSION
Low back pain has been seen to be a problem of great magnitude. It is common, costly in terms of social and economic disability and distressing to those who suffer it. As well as its direct effects of pain in the low back or limbs and resultant inability to perform the normal activities of life it may be associated with weakness and sensory loss. Although much of the time of the orthopaedic surgeon, the internist and the general practitioner is spent dealing with the problem, the impact on the individual and society does not seem to have been lessened significantly.
It has been shown degenerative changes occur even in the asymp• tomatic patient and these may, in association with certain other known and perhaps unknown factors lead to the development of back• ache in this individual. When conventional-or unconventional conser• vative treatment has failed lumbar intervertebral fusion is often considered. It was shown (p 54.) that the indications for lumbar intervertebral fusion may range from narrowed disc space with ver• tebral displacement through certain congenital anomalies such as hemivertebra or sacralization of the lumbar vertebra to instability or the inability to find protrusion of a disc at laminectomy for that purpose. The patient who has had a spinal fusion is considered to be at the end of the road as far as treatment is concerned. All he can 155. be offered is further surgery as a hopefully curative procedure if he has not had pain relief to that point, yet the result of multiple operations are successively poorer. It was this patient, then, that this study sought to assess.
In view of the controversy concerning the causes for disability in the post-fusion patient (p 59.) it seemed important to collect as much information as possible on each individual.
A fair call-in rate was obtained; the inability to trace 20 of 141 patients was due to lack of current address, a situation only applicable to those not receiving pensions from the Workmen's Com• pensation Board. Hence the overall results might appear to be a little worse than one would hope, with 11% unemployed and 60% missing one to two months of work time over the preceding two years due to backache. Although the unemployment rate is in fact little higher than the provincial average of 7.5% at the time of writing, all these people were engaged in productive work at the time of their original back "injury" and the economic loss to employee and employer alike is con• siderable, as pointed out by TROUP and others146' 262' 264.
Similarly, 55% of cases reported that their overall enjoyment of life was still negatively affected by their condition, in spite of a mean number of 1.98 back operations and a median time off work at the time of fusion of eight to twelve months. In fact, it has been 146 stated by KOSIAK et al that a speedy return to work is necessary to promote a good result: in this study it was shown a prolonged 156.
time for return to work was associated with poorer results of fusion.
Of the approximately 300 variables on which an observation was obtained for each patient it was felt that some §f the variables) were closely linked with success or failure of the operation as indicators 6f this)while the remaining variables could be split into two groups: those correlating with success and those not correlating with success. An index of success was necessary, against which all other observa• tions could be compared, as a foundation for our conclusions. The literature has shown a tendency to use pseudoarthrosis as a single criterion for assessing the result of fusion (p 57.) yet the function of the patient would appear to be more important. A single complaint of objective sign rarely serves as an indication for lumbar inter• vertebral fusion and hence cannot be subsequently used as a yard• stick for improvement. Insofar as any physician deals with a pre• senting complaint, then such presenting complaints must be used as 26 a basis for comparison of patients. BJERRING suggested the use of factor analysis based on success-oriented variables as a method for derivation of a success-failure index and the variable selection was based on functional features important to the patient, aiming to represent on the whole non-overlapping complaints which might, how• ever, be represented by more than one variable. It is interesting to note here that the two variables representing finance had the lowest factor loadings against "success", suggesting that the financial aspect of the problem is one of the less important to the post-fusion 157. patient with a low back complaint.
The purpose of using this factor analysis based largely on the patient's complaints was to eliminate observer error on the part of the examiner. It was of interest that the examiner's review opinion concerning the patient's degree of improvement subsequent to surgery showed a correlation of .94 with the success index, a figure of 1.00 indicating perfect correlation. This opinion was recorded at the time of examination, without the benefit of psychological test results.
It was after this method was developed that the prior use of a similar method by NASHOLD and HRUBEC came to light ' . Their use of certain objective data (p 138) to provide a Disability Index is perhaps better suited for their late follow-up of veterans than for the evaluation of factors involved in operative success because it focusses less upon the patient's ability to function. It is this functional ability and the quality of life associated with it with which we are primarily concerned, regardless of whether any deficiency was present before surgery or is the result of the operation, due to the effect of surgery or the individual reaction of the patient. Following development of this "success" index two other major groups of variables were considered: those showing a high degree of correlation with "success" and those not thus correlating. By using factor analysis again on those correlating variables the basic fea• tures underlying the result of the operation were unearthed. It was felt that it would be simpler to examine a limited number of factors 158. rather than to try and conceptualize in a non-arithmetical way the events underlying the importance of the 239 variables themselves.
The eight factors, as they were numbered during their production and as they were subsequently identified by the experimenters, are listed below. (1) Pain tolerance (2) Non-neuroticism
(3) Health-fitness (5) Single operation
(8) "Normal"-functioning lumbar spine
(12) Root deficit (13) Optimism for self (14) Mobility of self
Theise eight orthogonal (totally non-correlating) factors were used for three basic purposes. Firstly, they were used to compare with suggested causes for success or failure of fusion in the liter• ature. Secondly, they were used to provide a feedback to the clinical situation to assist in patient evaluation. Thirdly, they were used to determine the design of prospective studies into the causes of low back problems.
COMPARATIVE ASSESSMENT OF THE FACTORS.
The variation in individual tolerance for pain is a known phe- 71 293 nomenon ' , although the underlying features are not well under- 159. stood. It has been implicated in fusion failure by BARR et al16, among others. Pain tolerance appears to be separate from the problem of neuroticism, also stated in a rather vague and never fully assessed manner to be a cause for failure of fusion16' 148' 1^3' 211' 216' 2^8'
269. Emergence of pain tolerance and neuroticism as separate factors implies that, although neurotic patients may have a diminished pain tolerance, there is a phenomenon of pain tolerance variation between people which is independent of neuroticism.
The effects of neuroticism and intelligence are opposite but not overlapping. There may be a bias operative in favour of the intelli• gent in our study as they have smaller demands made on their backs occupationally, and this work effect might be reflected in the "success' score. Certainly, the more manual, unskilled job at the time of follow- up is inversely correlated with "success" (correlation: -0.25), while the heavy manual worker is known to take longer to return to work after a spell of back-related disability26^. In stating neuroticism to be associated with a poorer result it is important to be aware of the nature of measurements of neuroticism. For example, the hypochondriasis scale of the Minnesota Multiphasic 93 Personality Inventory is an index of bodily complaints : thus ele• vation is part of any physical illness which produces symptoms, i.e. virtually any physical illness. Similarly, depression is a product of physical illness, a normal reaction. However, neuroticism as seen here in factor 2 is neuroticism independent of any physical concomitant: 160. a separate factor in "success". This is in contrast to the view ex- 183 pressed by MACNAB who stated that disability consists of pain and the patient's reaction to it. Here it is shown that in addition to the patient's organic pain-producing pathology and his reaction to it, there is also a variable significant amount of neuroticism. Even a schizophrenia T-score over 70 on the M.M.P.I. would be expected in about 3% of a random population by definition and this must be carefully considered before assigning it a role in the back problem. (However, in this study, 18% of the cases showed a T-score greater than 70 on the Sc scale of the-M.M.P.I. Although the Sc scale score showed no correlation with "success", and hence is not important as a "success" determinant, it must be of significance in the low back pain problem for such a high rate of abnormality to occur.) The health-fitness factor has been described before. Lack of physd'cal health in the form of muscular unfitness may be associated with failure of the operation according to KRAUS14 8 as may obesity25 8 Although obesity has been shown here to be correlated with the pres• ence of spondylolysis, neither of these two variables alore signif• icantly correlated with "success" at the p < .01 level. Fusion of more than one level is more commonly associated with 89 158 252 258 failure of the operation ' ' ' and the multiply-operated patient is a particular problem89' 21^' 216. This may be due to an 215 233 inaccurate diagnosis ' especially if the level of the operative approach is inaccurate. 161.
Inaccurate preoperative diagnosis may also be responsible for
the emergence of the factor "nerve root deficit"; HAKELIUS showed a
speedier relief of pain and return to work in patients undergoing 102
discectomy in whom a true disc herniation was found . It was noted
in one patient in this study that a long fixation screw passed through
the lumen of the spinal canal; although his overall result was fiair
he had a marked three-level root deficit.
The two factors relating to optimism or ambition, and body mo•
bility or flexibility do not find a ready explanation in terms of
the body's reaction to the surgery. It can only be stressed again that
prospective evaluation with adequate follow-up is the only method which will provide conclusive evidence for involvement of these factors in
an etiological role.
One factor not found to be of importance in success was the presence of pseudoarthrosis as determined by conventional means. Fea•
tures not examined because of lack of documentation or difficulty in
standardizing information were operative technique and surgical skill, 233 252 both held to be important ' , particularly by the advocates of
each new method of fusion that has been introduced. In approximately
two-thirds of these cases, pre-, per- and postoperative details were not available, while no measure of surgical skill can be devised.
Surgical skill and operative selection are probably terms which can be used interchangeably. 162.
CLINICAL APPLICATIONS Specific findings of this study may find application in patient management, particularly with regard to examination and assessment.
The orthopaedic measures of motion and muscle power are shown to be impure organic measures and the availability of improved, more objective methods should lead to their clinical application (p 147).
Similarly, of the many radiological abnormalities implicated in
the pathogenesis of low back pain (p 150), only the presence of kissing vertebral spinous processes and an increased lumbosacral angle was
shown to correlate1 with "success". The presence of degenerative disc 216 signs other than kissing vertebral spines, implicated by some ' 233 252 ' , did not correlate either with success or severity of pain (Table 19), nor did correlation of the "generalized disc disease" factor with "success" reach significance. It has been shown that only the more severe radiological changes of degeneration correlate with 152 the incidence of low back pain while these are also occupation- 7 152 related ' . In this light limitation of liability in those with degeneration sometimes claimed by compensation carriers would seem a) to penalize only the occupationally involved person, b) unfairly-on two scores, as his disc degeneration may be re• lated to theoretically compensable) work-related stresses initially, while degeneration does not subsequently prejudice the results of fusion. Prospective evaluation of radiological abnormalities and the 163.
150 careful evaluation of their predictor value is essential ; the most useful information would be provided by a study including radiological examination and subsequent patient follow-up to identify those abnor• malities predisposing to the development of low back pain.
Psychological assessment of the patient with low back pain may be helpful in management. Even in the absence of firmer evidence for an etiological role of psychological abnormality it seems only prudent to persist further with conservative therapy in the case of a patient with evidence psychological abnormality on, for example, a well- standardized test such as the Minnesota Multiphasic Personality In• ventory. Such a patient should be given support if off work and should be rehabilitated even to light duties quickly - chronicity of the disease and a slow return to work are both avoidable and should be forestalled146' 147' 196.
PROSPECTIVE STUDIES
Three prospective studies are currently envisaged:
A PROSPECTIVE, CONTROLLED STUDY OF LOW BACK FUSION145: Patients in whom fusion is considered indicated by current standards would be randomly allotted to a surgical or non-surgical follow-up group. The value of the procedures could be assessed, as could the effect of therapeutic variables which could not be assessed in this study.
Predictor features leading to a successful result could be identified. 290 A PROSPECTIVE STUDY OF THE ETIOLOGY OF LOW BACK PAIN : TROUP 164. et al have suggested that an etiological study of low back pain should be prospective and industrially-based262' 26^' 265. A large prospec• tive industrially-based study is planned with random subject selection and prospective evaluation of possible predictor variables, whether physical, radiological or psychological, followed by long-term follow- up. Variables selected for evaluation would primarily be those shown in this study to be "success"-related or as representing the "success"- related factors. STUDIES OF THE ROLE OF MUSCLE TENSION IN LOW BACK PAIN AND. DEGENERATIVE LUMBAR DISC DISEASE2793: Mechanical factors are probably the initiators in lumbar disc disease193' 262 and occupational factors are implicated. Muscle tension might be an additional mechanical fac• tor and has been shown electromyographically to be associated with 6 3 low back pain . The planned study would evaluate the role of muscle tension in low back pain in humans and the modes and effects of its therapeutic reductions, and would also study the effects of increased muscle tension on the pathological changes of degeneration in animals. Thus, by studying the various factors prospectively the causal role can either be confirmed or denied. This will permit resolution of the shortcomings of the retrospective approach and will enable continued development of the theories highlighted in this work. 165.
SUMMARY
A follow-up study of 100 patients, who had all undergone lumbar vertebral fusion at least two years previously and were subjected to detailed historical, social, physical, radiological and psychological assessment, is reported. The report is based completely on the post- fusion, follow-up findings, as recorded preoperative findings were not uniform and hence not used.
Factor analytic methods were used to derive an index of success, based on the patient's current function, which was used as the major dependent variable in the formation of a correlation matrix of the majority of the variables. Using 55 variables, all highly "success"-correlated, further factor analysis was performed to identify factors closely associated with success or failure of the fusion operation. Particular attention was also given to the orthopaedic and radio• logical methods of patient assessment. Testing the hypotheses, the purpose of the study was: 1) To establish the multifactorial etiology for continued disability following lumbar intervertebral fusion. 2) To identify patient characteristics likely to be asso• ciated with success or failure of the operation. 3) To identify variables for further investigation of the etiology of low back pain disease. 166.
CONCLUSIONS
1. Lumbar intervertebral fusion may bring complete pain relief (in 17% of cases) and return to a productive life to some patients (40%), but 60% still.suffer marked disability.
2. The success of lumbar intervertebral fusion, as determined by patient function, is associated with eight fairly well-defined factors, representing different aspects of physical and psycho• logical health and disease. These were identified thus: (in order of importance)
Normal-functioning lumbar spine Mobility of body Freedom from neuroticism Pain tolerance
Minimum number of surgical operations Freedom from persistent nerve root deficit Optimism, ambition General health and fitness. These independently accounted for approximately 80% of the variance of "success" as determined by statistical means. This means, in practical terms, that the patient with a good result from a functional viewpoint will have a normal lumbar spine on examination, ability to move freely, will not be 167.
neurotic and will have a good tolerance of pain. He will prob•
ably have had a single operation, will be free from symptoms
ascribable to a nerve root deficit, will be optimistic and
ambitious, and will be in good general health. The patient with
a poor result will manifest the opposite features.
3. Radiological evidence of failure of bony fusion (pseudoarthrosis) at the site of operation does not correlate significantly with success or failure of the surgical procedure of lumbar inter- vertebral fusion. This may be due to the inadequacy of radio• logical diagnosis or to the fact that relief of disability is not dependent on production of bony fusion.
4. Orthopaedic methods of patient assessment are relatively in• accurate measures of organic impairment, reflecting to a large extent the patient's psychological state, and more objective, quantifiable measures should be employed. This is particularly necessary in assessing motion of the lumbar spine.
5. Radiological methods of assessment of the lumbar spine are dif• ficult to quantify and require better standardisation.
6. Psychological evaluation of the patient with a low back pain problem can provide useful information in the overall management of that problem, at any stage, including preoperatively.
7. This retrospective study of low back pain does not allow assign- 168. merit of etiological roles to the indentified factors, but has demonstrated the practicability of the methods employed and indicated the directions for prospective studies. 169.
Superior articular process
Transverse process
Spinous process
Inferior articular process
Spinous process Superior articular process . Inferior articular process
Transverse process
Vertebral canal
Figure 1: The Lumbar Vertebra 170.
Group 1
Group 2
- Group 3
Fif^ure 2; Mean MMPI profiles of the three outcome groups« pilot study. 171.
Retrospondylo• listhesis
Anterior vertebral body height
Anterior disc height
Posterior disc height Posterior joint subluxation
Lumbosacral angle
Figure 3: Radiological measurements on the lateral view. 172.
Figure 4: MVIPI profiles by "success" quartiles - main phase Overall mean ...... Highest quartile . ,.. Mid quartiles (2) _ Lowest quartile TABLE 1
BIOCHEMICAL DISC CHANGES WITH AGE AO DEGHtRATIOii AFTER iWLOR-
Disc constituent Disc degeneration Disc prolapse
1) Mucopolysaccharides keratan sulfate fractions (N) total, predominantly keratan sulfate (N)
2) Glycoproteins sugar moiety sugar moiety (N § A) due to degradation of glycoproteins
3) Collagen fibrillation - fibrillated; immature type (N)
(A)
4) Non-collagenous proteins appearance of B-protein B-protein CN) prematurely
(A)
5) Water ?
6) pH shows no change in either condition
N = nucleus A = annulus TABLE 2 RESULTS OF DISCECTOMY
Author Number of Follow-up . Result Employment patients time Satisfactory Unsatisfactory Same or Lighter or Unemployed excellent good fair worse or heavier handicapped same or poor
AITKEN2 a) 211 15% 20% 38% 25% 2.5% 11% 34% 49%
b) 200 2-5 yrs 25% 20% 21% 33% 33% 14% 12% 26% ' 47% 47%
BARR et al15 380 92% 29 Bosor 1351 33% 33% 44%
GURDJIAN et al101 915 3-13 yrs 19.9% 53.6% 19.7% 6.7% 21.4% 57.1% 15.4% 6.0% 17.9% 48.8% 25.6% 7.7% 20.8% 55.7% 18.1% 3.6% 16.3% 45.1% 26.1% 12.4% 1(12 138 . ?30% 88% 1% HAKELIUS 177 218 86% MOYES 194 374 > 5 yrs 60% NACHLAS
NASHOLD/HRUBEC196 C.300 20 yrs 23.3% 69% 7.7% 243 25 60% 28% 12% SIMON
WHITE, A.W.M.275 119 > 2 yrs < 40$
WHITE , J.C.276 130 of 380 33% 42% 14% 11% 79% . 11% 10% (same patients as BARR) seen personally TABLE 3 FUSION PROCEDURES AiW THEIR ORIGINATORS
Fusion type Probable originators Date Features Complications
Interspinous Albee 1911 Split spinous process, tibial graft Henle 1911 Graft on each side of spinous process Posterior arch Hibbs 1911 Interleaving scales on laminae Clothespin, Gibson 1931 Tibial 'clothespin' locked Donor site pain, esp. if H-graft between spines outer iliac cortex used Bosworth 1942 Iliac 'H'-graft locked between spines
Posterior bone Straub 1949 Paraspinal metal plate + with plate matching graft securing fixation . Wilson and Straub 1952 spinous processes Williams 1950 Twin plates securing spinous processes Posterolateral Hibbs 1911 Posterior arch extended to Campbell 1939 include transverse pro• Watkins 1953 cesses Adkins 1955 Intertransverse fusion alone Transfacet screws Tourney 1943 Short transfacet screws for Nerve root irritation King 1944 early fixation of vertebrae; posterior bone grafting Arch-body screws Boucher 1959 Long screw from posterior Nerve root irritation arch to body below, posterior bone grafting Anterior interbody Capener 1932 Anterior tibial graft High pseudarthrosis rate Speed 1938 sexual malfunction Mercer 1936 Iliac crest bone Posterior interbody Jaslow 1946 Posterior discectomy and bone-grafting Wiltberger 1957 Posterior 'dowi' graft insertion TABLE 4 fflFPARATIVE RESULTS OF REPORTED FUSION SERIES
SENIOR AUTHOR NUMBER IN Overall Results % Overall Fusion rate Fusion type SERIES Good Fair Poor Solid Pseudo• arthrosis
BOUCHER30 234 971 34 - - Posterior - long screw fixation
CALANDRUCCIO41 16 561 444 384 624 Anterior interbody
CLEVELAND46 598 94.81 15.24 83.54 16.54 -
DE PALMA60 78 591 274 144 Matched pairs of each -
DOMMISSE65 48 811 114 84 584 42% Posterior interbody
KING140 44 904 104 914 94 Transfacet screw fixation 153 250 784 134 94 - - - LEVY 159 17 59% 414 944 64 Meurig Williams plates LUCAS MACNAB185- 366 - - - 824 184 Several, compared 207 150 - -- - 834 174 Posterior - long screw fixation PENNAL PROTHERO211 430 - • - - 84.94 15.14 Posterior + posterolateral
RANEY215 43/46 514 124 374 834 174 Anterior interbody (salvage)
RANEY216 139 464 224 324 804 204 Anterior interbody (salvage)
STINCHFIELD252 100 - . - - 944 64 H-graft
THOMPSON258 1096 - - - 83.44 ' 16.64 Hibbs 177.
TABLE 5
SCORING CRITERIA FOR PATIENT GROUPING/ PILOT STUDY
TITLE SCORE
Drop in employment 1 or
Cessation of employment because of low back symptoms 3
Presence of pain 2
Time lost in last two years 2
Impairment of gait 2
Low back tenderness 2
Range of flexion 2
Range of extension 2
Range of lateral flexion, left 1
Range of lateral flexion, right 1
Straight leg raising 2
Patient's opinion of results 2
Patient's opinion of value of surgery 2
Opinion of examiner 4 TABLE 6
ORTHOPAEDIC ASSESSMENT OF PSYCHOLOGICAL PARAMETERS (%)
TEST 1 2 3 4 5 6 7 8 9 10
Score Extro• Indepen• Passive Dominance Eagerness Emotion• Anxiety Anxiety Verbal I.Q. version dency Aggres• to ality over Doctor- about his Ability siveness Recount About Patient pathology Troubles Troubles Relationship
Low 1 0 0 5 2 0 2 3 3 3 1
oo 2 12 7 28 13 6 11 19 10 15 18 '
3 19 24 15 42 15 25 24 28 42 36
4 14 12 19 20 20 24 24 18 33 31
5 31 27 21 17 33 29 27 25 6 13
6 16 27 9 6 22 8 3 14 0 0
High 7 8 3 3 0 4 1 0 2 1 1 179.
TABLE 7 MEASUREJWS OF VERTEBRAL BODY HEIGHT
Vertebral Body Minimum Maximum Mean S.D.
Ll Front 25 39 33.95 2.59 Rear 30 43 36.97 2.31 L2 Front 22 41 35.78 2.72 Rear 31 44 37.27 2.38
L3 Front 31 44 37.34 2.48 Rear 30 44 37.24 2.72 L4 Front 25 44 37.05 2.81 Rear 28 44 35.94 2.92 L5 Front 33 46 38.01 2.62 Rear 27 42 32.40 3.02
Mean ('Bodymean') 35.84 2.06 180.
TABLE 8
EASURBWS OF INTERVERTEBRAL DISC HEIGHT
Intervertebral disc Minimum Maximum Mean S.D.
Ll-2 Front 7 16 10.74 1.97 Rear 2 11 6.87 1.62
L2-3 Front 7 20 12.47 2.12 Rear 4 13 7.77 1.78
L3-4 Front 5 19 13.38 2.58 Rear 2 13 7.93 1.86 L4-5 Front 4 21 12.44 4.08 Rear 1 11 7.12 2.20 L5S1 Front 4 18 11.05 4.11 Rear 2 8 4.82 1.62
Mean ('Discmean') 9.34 1.51
N.B. Measurements of disc height were standardised relative to the appropriate level for use in correlations as 'Discnext': the height of the disc at the level above the fused level. 181.
TABLE 9 EASURLWTS OF POSTERIOR JOINT SUBLUXATION
Joint level Minimum Maximum Mean S.D.
Ll-2 0 12 1.73 2.10
L2-3 0 10 1.90 2.09
L3-4 0 9 2.46 2.35 L4-5 0 10 4.02 2.37
Mean ('Luxmean') 2.09 1.68
N.B. For correlation purposes, positive and negative values of posterior joint subluxation were used and standardised relative to the appropriate level for 'Luxnext', the degree of posterior joint subluxation at the level next above the fused level. 182.
TABLE 10 EASueers OF RLTROSPONDYLOLISTFESIS
Joint level Minimum Maximum Mean S.D.
Ll-2 0 12 0.99 0.97 L2-3 0 10 1.62 1.07 L3-4 0 5 1.65 1.12
L4-5 0 6 1.57 1.46
Mean ('Retroavg') 1.17 0.70
N.B. For correlation purposes, positive and negative values of retrospondylolisthesis were used and standardised, relative to the appropriate level for 'Retronex', the degree of retrospondy• lolisthesis at the level next above the fused level. 183.
TABLE 11 EASUREEi^S OF WERPffilCULAR DISTANCE
Vertebral Level Minimum Maximum Mean S.D.
Ll 22 34 27.37 2.05 L2 21 33 27.55 2.19 L3 23 34 28.67 2.21 L4 25 38 29.92 2.57 L5 28 41 31.31 3.34
Mean ('Ipedavg') 27.98 2.05 184.
TABLE 12 i^UREMS OF SAGITTAL DI AMEER OF VERTEBRAL CANAL
Vertebral Level Minimum Maximum Mean S.D.
Ll 17 27 22.81 1.97
L2 17 29 22.00 1.99 L3 16 27 20.66 2.13 L4 15 28 19.60 2.57 L5 14 21 18.00 2.74
L6 (where relevant) 16 24 20.00 5.66
Mean ('Sagmean') 20.93 1.87
186.
TABLE R FACTOR MATRIX FROM ''SUCCESS''-CORRELATII« VARIABLES;
CORRELATION OF FACTORS AGAIiMST "SUCCESS" (FIRST TWO
POST-DECIMAL FIGURES/ ROUNDED OFF.)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
YASIA3I.2
C?T 31 11 -04 01 -02 -12 02 08 07 02 15 -03 05 04 06 07 03 CILU.1 -15 -14 -13 -20 19 -OS -32 24 -04 03 16 -18 -41 02 -co -05 17 74 01 34 16 -02 -14 -01 11 08 01 02 03 1:! 10 -08 TAI-O-I -10 -71 -07 -47 -03 09 0> -12 07 02 -10 06 -07 01 08 00 13 NI?IHS -04 -74 -18 05 -24 06 17 -22 06 -02 00 -01 01 01 -16 -12 -12 -02 -76 -18 32 -23 06 19 -13 07 -03 07 -04 -02 -07 -12 -07 -04 B3C:< -11 -76 -01 -16 -14 14 -01 -21 -11 -07 06 22 -05 04 04 -10 11 04 -7a' -20 -11 -03 01 10 -13 -07 -06 -04 00 -11 -03 -12 -05 -18 HKF1PT 03 -81 06 -14 -04 06 -01 -01 00 ' 09 -11 -02 -11 -07 00 -01 02
STTP? -15 -05 -37 -19 -22 35 09 03 06 -04 -24 09 -12 -31 -12 -26 10 LEGS 01 -13 -» -03 -01 36 13 -07 05 -17 -08 23 -16 -04 -04 -50 -06 TO:T -2? 01 -57 07 01 -05 OS -38 -13 -06 26 10 15 09 06 -18 -03 02 -20 -74 -06 -03 -07 13 -04 -11 03 -00 30 -01 -21 05 -16 04 SSTSAT 13 -15 -78 -02 -03 10 -03 -06 02 08 -20 -17 -03 -18 -20 12 03
CP1C3 08 21 -01 79 -05 11 01 16 01 -16 20 -02 01 09 01 01 04 CPISP -07 29 05 75 06 07 -03 07 09 04 -20 07 12 04 15 -01 15
1SDFI.EX -30 -02 -38 22 -43 07 -06 -17 05 -04 07 -20 18 -13 07 -09 18 UK:O 13 -09 -07 -20 -61 06 -07 -16 10 -04 -09 34 15 07 17 -?3 00 FUSIOSO -07 -32 -03 03 -73 13 04 -16 -10 07 -07 -06 -17 -02 -07 00 -14 0PKUT5 -02 -35 02 05 -79 -01 16 -12 -11 -03 -08 03 -20. -07 05 01 -01
-21 -00 ' 00 11 -09 80- 01 -04 -02 05 02 04 03 -11 -11 01 -03 BaCKS • 05 -26 -07 05 01 76 03 -13 -01 01 -03 -10 -21 05 -06 -10 -03 OBI?CH -00 -13 -07 -04 -09 02 55 -18 -01 -07 -OJ 03 -03 -11 -03 04 -10 Cm ^Pft 01 -33 -02 -06 01 05 74 -20 -05 04 -04 08 -09 -26 01 -:e 02
HTP2I3CT -19 -37' -01 -12 -11 13 17 -42 -12 16 02 27 -10 -21 -38 03 11 ABDPO'./A . -io . 19 -03 -18 -07 -18 28 -45 21 07 17 15 -42 13 -25 00 -13 LOK3CT . 10 -24 -25 -15 -16 28 -03 -47 -13 -27 -24 04 23 -08 -03 22 -11 05 07 -22 -22 -32 29 13 -49 -25 -21 -01 13 09 -09 08 11 17 SLR -32. -02 -23 -19 -11 -05 16 -51 -04 -08 -29 20 -11 -06 -02 -13 04 oBjarr -17 -32 -28 06 -27 12 15 -54 -06 -03 -09 18 -23 -18 -04 -04 07 SPASM 11 -15 20 00 -11 29 28 -57 -03 -03 -04 -01 -12 -03 -19 02 04 ABBPOVB -15 -08 -05 -02 -03 16 19 -58 -07 -10 28 17 -19 -3« -14 02 05 CASSIS!! 06 -23 15 02 04 ->3 17 -60 -22 04 -04 20 08 03 -28 -26 -15 BACEPOK -21 -31 -16 -04 -05 04 -12 -69 -12 -02 11' ' 11 -12 -17 -05 -08 -15 flBtTWO -05 -14. -09 -13 -21 -02 . 06 -76 14 -06 -09 -06 -06 -18 04 -03 16
CATIQ 10- 04 02 16 16 -19 -06 15 73 09 05 -04 -17 08 19 • io. -02 HZA3ACHZ ' -03 -42 -01 -08 -10 40 05 -10 5? -09 09 '09 08 -10 12 00 -10 BP -02 -18 -14 03 -00 -08 02 -09 -69 02 -06 08 -34 -04 28 10 -11
PAtrara 03 -20 -00 09 -13 22 -12 -36 -15 47 02 22 16 -23 -25 -14 -18 STA.-1CE -06 -16 -00 11 -08 04 "3 -19 -07 -82 03 07 05 -11 -13 -16 -07
BET0R5 -36 -28 01 -09 -28 02 22 -08 -24 -01 36 04 -02 -21 -15 02 30 -04 80V -19 T12 -09 -05 -17 02 15 -07 -15 01 -76 01 08 -05 -06 -17
IHSPOV -06 -02 -07 08 -02 -05 03 -21 -05 -05 01 78 -10 -18 -08 Of 01 WALnra; -11 -17 -13 -28 -28 17 12 -05 -04 46 06 49 13 05 11 -07 -22
icnw 13 47 -02 02 10 -16 -07 13 07 09 05 -11 61 10. -01 -03 03 fCPCT -00 23 -03 18 19 -21 -04 19 06 -06 -17 -05 59 12 07 27 07
CAR -27 -18 -20 -14 -07 02 25 -36 -11 ' 06 11 -11 -28 -40 -16 01 08 LiPTiiro 17 -06 -12 -02 03 -01 09 -44 -06. 17 -19 11 09 -58 04 -23 -02 L0'.3ACK -15 -12 -oe -15 06 06 08 -23 -00 -13 06 -06 02 -60 -11 -32 15 BES3INC -06 -03 -23 03 -13 05 23 -09 -06 -10 -05 24 -13 -6) -02 03 .-18
RECTAL -03 -09 02 -20 -43 -07 -37 -15 05 -06 -01 14 01 -15 -49 10 -04 IHT23CAP -07 -17 -14 -07 18 24 08 -17 -03 -13 -04 01 -07 -03 -75 -08 -03 BCTTOCE -09 -17 -10 03 -08 03 03 -07 -02 -06 -14 -08 -05 -18 -02 -70 02
TALCALVA •111 -10 -11 -07 -08 00 13 -33 04 14 -16 39 -25 -02 -26 05 46 SIBS -08 -08 05 -32 -16 11 22 00 -01 04 -12 09 -21 -07 -13 06 -59
8BCCS33 28 34 21 14 25 -15 -U 49 07 06 02 -22 22 40 14 10 01 187.
TABLE 15
INSCRIPTION OF THE 17 "SUCCESS''-RELATFiJ FACTORS, THEIR CORRELATION WITH "SUCCESS" AND THE VARIANCE OF "SUCCESS" ACOQUNTED FOR (SEE TABLE 14 FOR FACTOR LOADINGS)
Factor Description Correlation P= 1 variance Number coefficient of "success1
8 Normal back orthopaedically + 0.4851 .0000 23.53 14 Mobility of self + 0.3973 .0001 15.78 2 Non-neuroticism + 0.3352 .0008 12.39 1 Pain tolerance + 0.2821 .0045 7.96 5 Single operation (vs. multiple)* 0.-2502 .0116 6.26 12 Root deficit - 0.2189 .0271 4.79
13 Optimism for self + 0.2187 .0273 4.78 3 Health-fitness + 0.2115 .0327 4.47
% variance accounted for by factors showing significant success-
correlation (p < .05) 79.96
6 Generalised disc disease - 0.1484 .1364 2.20
4 Social competence + 0.1438 .1494 2.07 15 + 0.1362 .1731 1.86 7 Orthopaedic psychology - 0.1060 .2940 1.12 16 1 + 0.1004 .3217 1.01 9 1 + 0.0657 .5232 0.43 10 Postural + 0.0642 .5333 0.41 11 1 + 0.0174 .8402 0.03 17 1 + 0.0149 .8552 0.02
Overall % variance of "success" accounted for by the 17 factors 89.11
? signifies unidentifiable factor. 188. TABLE 16 LOADINGS OF THE i^ASHOLD MJ.HRUBEC DISABILITY -INDEX
1 Atrophy of legs 22 2 Weakness of legs 48 3 Decreased sensation 44
4 Decreased reflexes 21
5 Loss of lordosis 42 6 Restricted motion 39 7 SLR test 42
8 Changes in occupation history 15 9 Limitation - back pain 65 10 Limitation - back weakness 30
11 Limited use of legs 68 12 Handicap in employment 76
13 Functional evaluation 76 14 Complaint of back pain 51 15 Complaint of leg pain 50 16 Change in employment 47 17 O.A. compensation 45 18 Subsequent surgery for herniated nucleus pulposus 21 189.
TABLE W,
PSYCHOLOGICAL SCORES ON 4 PARAMETERS BY QUARTILE GROUPING
Upper Middle (2) Lower
"Success" 1.16 0.10 -1.36
I.Q. 87.88 83.32 78.20
Beck 4.29 7.44 13.00
Taylor 13.76 18.22 24.09 190.
saraswr K? * ......
ACS - - J
FUSI05D ii 28 22 7? t TABLE 18
CATM 28 22 42 - - J
BSCS i2 37 37 - - 22 *
!!KPinS iO - 1+7 - - 12 60 S
TAYLOR W> - - 27 2?' - 70 JO t
TILT ...... t Correlation matrix of certain orthopedic
L0KFL2I .-33— — $
examination methods with the "success" FLEXTOO 52 i2 - 3* 27 - 32 36 28 35 - t
LUKOT 46 W 25 26 32-22 32 36 32 - -' 51 8 _ lndeX' CCTtai" P"*"*010^1 acd radiological
PAISEXT i2 53 - - 41 22 35 36 - .- - - 35 S variables. All coefficients shown reach
STPESHT 80 62 l 3? 38 22 58 42 42 54 22-54 36 74 S ' signif ioance ( p < .05 ). RIFLE* i2 32 39 31 31 41 27 22 - 35 22 53 61 - 41 J . .
X » correlation, p < .1
HEITSI_3t <8 64 - . 33 2§ 51 44 28 51 - 61 58 83 73 47 J
TECTSR ^2 55 - T - Jl 38 26 22 - - 56 43 65 71 41 91 J
PVTOhG Jl 58 - 56 48 - 63 63 36 - - -50 5 9 5 « 50 70 74 71 8
M3TCR3 X J
IBDPO'JB 72 58 - 24 - 28 34 34 - 52 33 68 44 49 69 51 58 78.50 -'S .
3ACZP0V 80 70 - 30 37 26 54 50 38 '- - 81 57.61 67 52 78 81 56 - 80 S '
SLR 68 47 - 34 29 28 31 24 30 - - 66 44 36 51 42 61 58 58 52 4J 59 3
'inSTE ......
L35PCV 46 - - - - - 29 ------48 43 34 5} 49 56 - 48 39 41 -' f»
rjTRXlSE ...3*33...... X----J3S
' 3SBAOC- 25 • X 33 27 - 28 31 29 ------30 - - - -•------0":t
L0SSR1 26 - -. - - - 34 - 42 . . - 45 46 3'- - -•- - - 44 - - X - - «
CTT 34-i4r - 2J 22------22- - -.41- - 24 - - - . - $
" LYSIS - J
POROSIS - -X. ------I ...... t
DYE X- - 25 ------36 - - 64 . - - 33 22 *3 ------$
LEVSLA 26 28 - 41 38 - 29 32 25 - -- 44- 35 ---67 ------57 - 8
SOLID .--20------..-.--.------12 36 8
SCR5W3 - -- -.------.------.--.--I
3EGSH. ------2J------.------I
SPURS -- 30 - -24 ...... 53 - -X--44-- ...... 28 -S
OSTi-DPltY - - 56 - - 35 25 - '27 - - - 43 - - 38 - - .------•- 37 39 ------48 ft'
3AASTKUP 24 - 32 ... 25 28 26 ------31 X 42 8 DISCH3AH - - 35- 3JZ- - 26---$
. RETROAVG ------»l-...-...----.jJ...... 27 24. 3 LUXKEAH ..30 - - 22 - -- 39 - - 29 -- 27 ------31 - -- -- 32 - -- 34 36 27 - 32 8
DISCMEXT ------X------22------32 -4011---.-77--$
S2TH0X2X ------X------43 X------X------58 -.-3
LUXH-XT _-- 32 -.X--- 29 --X------22---- 26 ----26-- 34 74 . 25 l 191 .
TABLE B S3V:-SI7Y •
ACE ' Correlation matrix of the radiological variables B3C!T •52 37 37 J
T.1YL09 a - - 70 I with the " success " index, certain psychological
FAT7ACT s and mechanical variables.. All cqefficients shown
...... ft; I reach significance•( p K .05 ). STA'CE ii 37 30 28 - X - » a - si * X » correlation, p < .1 TUT ----- 60*. - - •*'
1IDK23! X---I LTTS:3 su x" - . - - »
'------X.----S
P0F.C3IS - - X - - 60
PTUCTTBS ..X..X..-S ore X----X------J - ... 36 I
28 28 - 29 25 - - *1 - - X - - 57 - - - t
SOLID 12 - .... 36 I
-•--X---3* j.
SCB3MK) ----- T 77!
SCEHOBL M .. n x » - - i
KOTTSSCN '--- 53 80 -
DECE! ----- 59 63 ------S
S;t'!S -'- 30 ------28 -'--•'. J
OST-CPKY - - 56 25 27 ...... ------1.8 »
LICCiK - - - - 69 »
BAAS7RUF 2j» - 32 25 26 - 31 X 42 -' J
20 22 24 20 - 26 -- - X -- 55 -----.---!•> - - --X- I
3ISC2AH X 22 35 35 --- 32 26 ..... J
WJOSATJ .- 30 - --- 32 - 39 --32-.---_3H36-27.-l
HETP.CAYC 585_Z------3£il-- 27 35 2 IPSU3AJI --20---W1---X.X-----31-----.X--.---I SACISW 22 -- 27 22-X----.---X ...55$ ...... 32 - . X X.. ------21 26 I DIECSiXT ------32--. J40 21 ------1 --X 77 -----I LOTS-XT .-]2-.-.X-2»-.-..--26...--..2<....7f>3»--..| HSTSKieX ---X-28 --12- 33 M - •- ...... 37--- - ja-- - -- Ml b !2 M ? u, *• £ G- H 1 192. BIBLIOGRAPHY 1. AHLGREN, E.W., STEPHEN, CR., LLOYD, A.C. and MCCOLLUM, D.E.: Diagnosis of Pain using a Graduated Spinal Block Technic. JAMA. 195: 813-816, 1966. 2. AITKEN, A.P. : Rupture of the Intervertebral Disc in Industry: Further observations on the end-results. Amer. J. Surg. 84: 261-267, 1952. 3. ALLBROOK, D : Movements of the Lumbar Spinal Column. J. Bone Joint Surg. 39B: 339-345, 1957. 4. AMATO, V.P., BOMBELLI, R.: The Normal Vascular Supply of the Vertebral Column in the Growing Rabbit. J. Bone Joint Surg. 41B: 782-795, 1959. 5. AMELAR, R.D., and DUBIN, L.: Impotence in the Low-back Syndrome. JAMA. 216: 520, 1971. 6. 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SISSONS, H.A. : Osteoporosis and Backache. Neckache and Backache (eds. GURDJIAN, E.S. and THOMAS, L.M.). Spring• field, Illinois. Charles C. Thomas. 1970. 246. SOUTER, W.A. and TAYLOR, T.K.F.: Sulphated Acid Mucopolysaccharide Metabolism in the Rabbit Intervertebral Disc. J. Bone Joint Surg. 52B: 371-383, 1970. 213. 247. SPLITHOFF, CA.: Lumbosacral Function: Roentgenographic Comparison of Patients With and Without Backaches. JAMA. 152: 1160-1163, 1953. 247a. SPURLING, R.G.: Lesions of the Intervertebral Disc. Springfield, Illinois. 1953. 248. STARK, W.A. : Spina Bifida Occulta and Engagement of the Fifth Lumbar Spinous Process. Clinical Orthopedics and Related Research. 81: 71-72, 1971. 249. STAUFFER, R.N., and COVENTRY, M.B.: A Rational Approach to Failures of Lumbar Disc Surgery: the Orthopedist's Approach. Orthopedics Clinics of North America. 2: 533-542, 1971. 250. STEINER, S.D. : Incidence of Neck Pain and Back Pain in an In• dustrial Group. Neckache and Backache (eds. GURQgiM, E.S. and THOMAS, L.M;). Springfield, Illinois. Charles C. Thomas. 1970. 251. STEWART, H. : The Relationship of Physical Illness to the IPAT 16 Personality Factors Test. Psychol. Rep. 18: 264-266, 1966. 252. STINCHFIELD, F.E., and SINTON, W.A.: Criteria for Spine Fusion with Use of "H" Bone Graft Following Disc Removal. Archives of Surgery. 65: 542-550, 1952. 253. SULLIVAN, J.D., FARFAN, H.F., and KAHN, D.S.: Pathologic Changes with Intervertebral Joint Rotational Instability in the Rabbit. Canadian Journal of Surgery. 14: 71-79, 1971. 254. SUSSMAN, B.J. : Experimental Intervertebral Discolysis. Clinical Orthopedics and Related Research. 80: 181-190, 1971. 255. TAYLOR, T.K.F., and AKESON, W.H.: Intervertebral Disc Prolapse: A Review of Morphologic and Biochemic Knowledge Concerning the Nature of Prolapse. Clinical Ortho• pedics and Related Research. 76: 54-79, 1971. 256. THATCHER, D.S. : One Hundred Cases of Low Back Pain. American Journal of Surgery. 97: 383-387, 1959. 214. 257. THOMAS, G., and RAU, E.: Ueber die Funktion der RUckenstreck Musculatur. Z. Orthop. 106: 737-745, 1969. 258. THOMPSON, W.A.L., and RALSTON, E.L.: Pseudarthrosis Following Spine Fusion. J. Bone Joint Surg. 31A: 403-405, 1949. 259. THURLOW, H.J. : General Susceptibility to Illness: A Selective Review. Canadian Medical Association Journal. 92: 1397-1404, 1967. 260. TKACZUK, H. : Tensile Properties of Human Lumbar Longitudinal Ligaments. Acta Orthopedica Scandinavica. Supp. 15, 1968. 261. TROUP, J.D.G. : Relation of Lumbar Spine Disorders to Heavy Manual Work and Lifting. Lancet. 1: 857-861, 1965. 262. TROUP, J.D.G. : Research into the Causes, Prevention and Treat• ment of Low Back Pain and Sciatica: its Relevance to Occupational Medicine. Paper read to the So• ciety of Occupational Medicine at the Institute of Orthopedics, London. 1971. 263. TROUP, J.D.G., HOOD, C.A., and CHAPMAN, A.E.: Measurements of the Sagittal Mobility of the Lumbar Spine and Hips. Annals of Physical Medicine. 9: 308-321, 1968. 264. TROUP, J.D.G., ROANTREE, W.B., and ARCHIBALD, R.: Industry and the Low-Back Problem. New Scientist. 45: 65-67, 1970. 265. TROUP, J.D.G., ROANTREE, W.G., and ARCHIBALD, R. McL.: Survey of Lumbar Spinal Disability: A Methodological Study. Private Circulation. 1972. 266. VERBIEST, H. : Further Experiences on the Pathological Influence of a Developmental Narrowness of the Bony Lumbar Vertebral Canal. J. Bone Joint Surg. 37B: 576- 583, 1955. 267. WALTERS, A. : Emotion and Low Back Pain. Applied Therapeutics. 8: 868-871, 1966. 268. WALTERS, R.L., and MORRIS, J.M.: Effect of Spinal Supports on the Electrical Activity of Muscles of the Trunk. J. Bone Joint Surg. 52A: 51-60, 1970. 215. 269. WATKINS, M.B. Posterolateral Fusion in Pseudoarthrosis and Posterior Element Defects of the Lumbosacral Spine. Clinical Orthopedics and Related Research. 35: 80-85, 1964. 270. WAUGH, O.S., CAMERON, H.F., SCARROW, H.G., and HOWARTH, J.C: Followup on Lumbar Disc Lesions. Canadian Medical Association Journal- 61: 607-611, 1949. (cited in SPURLING, R.G. /a) 271. WEINSTEIN, M.R.: The Illness Process - Psychosocial Hazards of Disability Programs. JAMA. 204: 117-213, 1968. 272. WESTRIN, C C, HIRSCH, C, and LINDEGARD, B.: The Personality of the Back Patient. Clinical Orthopedics and Re• lated Research. 87: 209-216, 1972. 273. WHITE, A.A., and HIRSCH, C: Significance of the Vertebral Pos• terior Elements in the Mechanics of the Spine. Clinical Orthopedics and Related Research. 81: 2-14, 1971. 274. WHITE, A.W.M . The Compensation Back. Applied Therapeutics. 8: 871-874, 1966. 275. WHITE, A.W.M . Low Back Pain in Men Receiving Workmen's Com• pensation - a Followup Study. Canadian Medical Association Journal.. 101: 61-67, 1969. 276. WHITE, J.C. Results in Surgical Treatment of Herniated Lumbar Intervertebral Discs: Investigation of the Late Results in Subjects with and without Spinal Fusion - A Preliminary Report. Clinical Neuro• surgery. 13: 42-54, 1966. 277. WILEY, J.J., MACNAB, I., and WORTZMAN, G.: Lumbar Discography and its Clinical Application. Canadian Journal of Surgery. 11: 280-289, 1968. 278. WILEY, A.M. and TRUETA, J.: The Vascular Anatomy of the Spine and its Relationship to Pyogenic Vertebral Osteo• myelitis. J. Bone Joint Surg. 41B: 796-809, 1959. 279. WILFLING, F.J. : A Psychological Follow-up of 100 Post-fusion Patients. Thesis in Preparation. Vancouver. 1972. 216. 279a. WILFLING, F.J., and WING, P.C.: The Pathogenesis of Low Back Pain: Experimental Research Proposal. Vancouver. Ortho• pedic and Trauma Research Unit, University of British Columbia. 1972. 280. WILLIAMS, P.C. : The Lumbosacral Spine. New York. McGraw-Hill Book Company. 1965. 281. WILLIS, T.A. : Backward Displacement of the Fifth Lumbar Vertebra: an Optical Illusion. J. Bone Joint Surg. 17: 347- 352, 1935. 282. WILLIS, T.A. : The Phylogeny of the Intervertebral Disc: a Pictorial Review. Clinical Orthopedics and Re• lated Research. 54: 215-233, 1967. 283. WILSON, J.C. : Low Back Pain and Sciatica: a Plea for Better Care of the Patient. JAMA. 200: 705-712, 1967. 284. WILSON, P.D. : Low Back Pain, a Problem for Industry. Archives of Environmental Health. 4: 505-510, 1962. 285. WILTBERGER,. B.R.: Surgical Treatment of Degenerative Disease of the Back. J. Bone Joint Surg. 45A: 1509-1516, 1963. 286. WILTSE, L.L. : Spondylolisthesis in Children. Clinical Ortho• pedics and Related Research. 21: 156-163, 1961. 287. WILTSE, L.L. : Spondylolisthesis: Classification and Etiology. American Academy of Orthopedic Surgeons Symposium on the Spine. St. Louis. The C.V. Mosby Company. 1969. 288. WILTSE, L.L. : The Effect of the Common Anomalies of the Lumbar Spine upon Disc Degeneration and Low Back Pain. Orthopedic Clinics of North America. 2: 569-582, 1971. 289. WILTSE, L.L., and HUTCHINSON, R.H.: Surgical Treatment of Spondylo• listhesis. Clinical Orthopedics and Related Re• search. 35: 116-135, 1964. 290. WING, P.C, and KOKAN, P.J.: A Proposal for a Prospective Etiolog• ical Investigation of Low Back Pain in an In• dustrial Setting. Vancouver. Orthopedic and Trauma Research Unit, University of British Columbia. 1972. 217. 291. WOLFE, H.J., PUTSCHAR, W.G.J., and VICKERY, A.L.: Role of the Notochord in the Human Intervertebral Disc. Clinical Orthopedics and Related Research. 39: 205-212, 1965. 292. YAMAJI, K., and MISU, A.: Kinesiologic Study with Electromyography of Low Back Pain. Electromyography. 8: 187, 1968. 293. ZBOROWSKI, M. : People in Pain. San Fransisco. Jossey-Bass. 1969. 218. APPENDIX 1. This appendix shows the orthopedic data collection forms in the style used during the study. The figures at the left margin indicate the anticipated column or columns the data would occupy on the punched cards initially used as input for the computer pro• cessing. The name in block letters is that used in data analysis and as shown in certain of the tables described in the text (these were required as the name on the computer printout must usually be limited to eight characters). An asterisk against this name indi• cates when recombination of the groups was required for a partic• ular variable to facilitate its statistical manipulation by making it more quantitative: for example, the variable recording smoking habit was rearranged by such recombination to reflect the degree of the smoking by the individual. A second code name in parentheses indicates the name assigned to a recombined variable if the recom• bination was not done at the beginning of the analysis. Not all variables were used for purposes of correlation in the light of initial responses to each of them. 219. Low Back Pain - Patient Self evaluation. ' Patient code number Instructions: In all cases, place a ring round the number opposite the one answer that seems most appropriate to you. The column on the left refers to the way you were approximately one month before your fusion operation, the column on the right to the way'you are now. If you have difficulty, please ask for help. Try and answer all the different parts. Nature of Pain One month before fusion Now Severity of pain 9-10 0 0 No pain 1 1 Mild pain, not a problem 2 2 Pain annoying, but forgotten during activity SEVERITY 3 3 Pain present even during activities 4 4 Moderate pain, interferes with activities or sleep 5 5 Pain prevents activity or sleep 6 6 Severe pain, is immobilising Location - low back 11-12 0 0 Ho pain in low back 1 1 Low back, in the centre 2 2 Low back, on the left mostly 3 3 Low back, on the right mostly LOWBACK* 4 4 Low back generally Pain between shoulder blades - do you have it? 13-14 0 0 No 1 1 Occasionally 2 2 Often INTESCAP 3 3 Most of the time Fain in the neck - do you have it? 15-16 0 0 No 1 1 Occasionally 2 2 Often NECK(S) 3 3 Most of the time / 220. One month before fusion Now Location of pain in buttocks or thighs 17-18 0 0 No pain in these places 1 1 Left buttock 2 2 Right buttock 3 3 Both buttocks BUTTOCK* 4 4 Left thigh 5 5 Right thigh 6 6 Both thighs 7 7 Left buttock and thigh 8 8 Right buttock and thigh 9 9 Both buttocks and thighs Do you feel pain in the tip of your tailbone? 19-20 0 0 No 1 1 Occasionally 2 Often COCCYX* 3 Most of the time Do you get, migraine or headaches? 21-22 0 0 Seldom or never 1 1 Occasionally 2 2 Frequently HEADACHE Location of pain in leg's and feet. 23-24 0 0 No pain hero 1 1 Left calf 2 2 Right calf LEGS* 3 3 Both calves 4 4 Left calf and foot 5 5 Right calf and foot 6 6 Both calves and feet 7 7 Left heel and/or foot 8 8 Right heel and/or foot 9 9 Both heels and/or feet Factors Affecting The Pain Coughing, sneezing or straining at stool 25-26 0 0 No particular effect on pain 1 1 Improves or lessens pain 2 2 Makes pain worse 3 3 Have not tried it VALSALVA* 4 4 Cannot tell Sitting in an upright or firm chair 27-28 0 0 No particular effect on pain 1 1 Improves or lessens pain 2 2 Makes pain worse 3 Have not tried it SITTING* 3 4 4 Cannot tell 221 . One month before fusion Now Sitting in a comfortable or reclining chair 29-30 0 0 No particular effect on pain 1 1 Improves or lessens pain 2 2 Makes pain worse 3 3 RECLINE* Have not tried it 4 4 Cannot tell Lying flat 31-32 0 0 No particular effect on pain 1 1. Improves or lessens pain 2 2 Makes pain worse LYING* 3 3 Have not tried it 4 4 Cannot tell Walking 33-34; 0 0 No particular effect on pain 1 1 Improves or lessens pain WALKING* 2 2 Makes pain worse 3 3 Have not tried it 4 4 Cannot tell Bending forward or sideways 35-36 0 0 No particular effect on pain 1 1 Improves or lessens pain 2 2 Makes pain worse BENDING* 3 3 Have not tried it 4 4 Cannot tell Lifting 37-38 0 0 No particular effect on pain 1 1 Improves or lessens pain 2 2 Makes pain worse LIFTING* 3 3 Have not tried it 4 4 Cannot tell Lying curled up 39-40 0 0 No particular effect on pain 1 1 Improves or lessens pain 2 2 Makes pain worse CURLED* 3 3 Have not tried it 4 4 Cannot tell neat or warm-on 43-44 0 0 No particular effect on pain 1 1 Improves or lessens pain 2 2 Makes pain worse 3 HEAT* 3 Have not tried it 4 4 Cannot tell 222. One month Now before fusion Cold 45-46 0 0 No particular effect on pain 1 1 Improves or lessens pain COLD* 2 2 Makes pain worse . 3 3 Have not tried it 4 4 Cannot tell Manipulation by chiropractor or friend 47-48 0 0 No particular effect on pain 1 1 Improves or lessens pain 2 2 Makes pain worse MANIP* 3 3 ' Have not tried it 4 4 Cannot tell Simple pain pills (such as aspirin) 49-50 0 0 No particular effect on pain 1 1 Improves or lessens pain 2 Makes pain worse ANALGES* 2 3 3 Have not tried it 4 4 Cannot tell Corset or orthopedic type belt 5.1-52 0 0 No particular effect on pain 1 1 Improves or lessens pain 2 2 Makes pain worse 3 Have not tried it CORSET* 3 4 4 Cannot tell The time of day the pain is worst 53-54 0 0 No pain 1 TIME* 1 The pain has no relation to the time of day 2 2 Morning 3 3 Middle of day 4 4 Evening 5 5 Evening and night 6 6 Morning and evening 7 7 Night 8 8 All day 9 9 Day and night Stiffness 55-56 0 0 No stiffness or very little 1 1 Stiffness mostly in the back 2 2 Stiffness mostly in the left leg STIFF* 3 3 Stiffness mostly in the right leg 4 4 Stiffness mostly in both legs 5 5 Stiffness in the back and left leg 6 6 Stiffness in the back and right leg 7 7 Stiffness in the back and both legs Weakness in the legs 57-58 0 0 No leg weakness 1 1 Weakness in. both legs 2 2 Weakness in left leg Weakness in right leg WEAKNESS* 3 3 223. One month Now beforo fusion Changes in feeling in legs 59-60 0 0 No changes 1 1 Change in feeling in right leg 2 Change in feeling in left leg SENSAT* 2 3 3 Change in feeling in both legs 4 4 Change in feeling in other parts Ability to manage Daily Life Household chores. Mark the one that indicates the most difficult of those listed that you manage. 61-62 0 0 Cannot manage anything 1 1 Washing up 2 2 Cooking CHORES* 3 3 Cleaning kitchen (inverted) 4 4 Cleaning and tidying house 5 5 Making beds 6 6 Washing or polishing floors 7 7 Carrying a heavy object such as a suitcase 8 8 Moving heavy furniture 9 9 Doing heavy digging in the garden or similar 63-64 0 0 Walking. 1 1 No limit to walking I have to stop after about a half mile because of MOBILE 2 2 discomfort I can only walfe 2-3 blocks before I must rest 3 3 I can only walk very short distances, but can 4 4 manage stairs and get around the house. 5 5 I cannot manage stairs 6 6 I need help to move even in the house I have to use a wheelchair Caring for yourself - mark the most you can do. 65-66 0 0 Unable to look after myself 1 1 I can feed and wash myself but need help dressing 2 2 I am able to do the above; I can cut my own toenails I can dress myself completely but need help with 3 3 IHDEPEND* some things. (inverted)4 I am totally independent 67-68 Sitting, getting up 0 0 Neither of these gives me any discomfort 1 1 I can sit down but getting up from the sitting CHAIR* position may hurt. Getting up does not hurt but actually sitting may hurt 3 3 Both sitting down and getting up may hurt 4 4 Because of difficulty I need help wit-h sitting down and rising from a chair 69-70 Picking things up off the floor 0 0 I can pick things up off the floor without difficulty FLOOR* 1 1 Bending hurts, but I can straighten up without difficulty 2 2 I can get down to pick something up but straightening hurts 3 3 Both bending and straightening up hurt 4 4 Because of discomfort I just can't pick things up off the floor 224. One month Now before fusion Marital status 71-72 0 0 Single 1 1 Married (one marriage only) 2 2 Married(l have been married more than once) MARITAL* 3 3 Separated 4 4 Divorced 5 5 Widowed 6 6 Engaged to be married 7 7 'Common-law' (living together, not married) Marital relationship (includes common-law partnerships) 73-74 0 0 Single at present 1 1 Happy and fairly secure in my present relationship 2 2 Fairly happy, but quite obvious ups and downs BLISS 3 3 Our relationship is not very good 4 4 We are likely to split up soon 75-76 Sexual life-general - Mark the one that most applies to you 0 0 Normal - no problem at all SEX* i i Back pain necessitates the use of certain positions 2 2 Frequency is greatly limited by back pain 3 3 Both of the above are true (1 and 2) 4 4 Intercourse is not possible because of some other illness or difficulty in either partner Social activities - going out with friends; to parties or dances etc. 77-78 0 0 No limitation for any reason 1 1 No change in the type of activities, but less often because of pain 2 2 I have had to change to easier activities because SOCIAL* of back pain 3 3 I can do very little' because of pain 4 4 I have had to change activities for some other reason Financial 79-80 o 0 I am comfortably off financially 1 1 I have no debts, but would like to have more money in reserve. 2 2 I have some small debts MONEY 3 -j I am in a fairly serious financial position 81-82 o 0 Work 1 1 I am not working, but this is not because of illness I do not work because of illness, but not because WORK* 2 2 of back trouble. I am able to continue my usual work without 3 3 difficulty. I find my work quite difficult and uncomfortable 4 4 because of my back trouble 5 5 I can only work part time because of my back trouble I have had to change to an easier job because of 6 6 this back trouble. I have had to change to an easier job for some other reason. 225. One month before fusion Now 83-84 Car driving - mark the answer most appropriate to you 0 0 I do not drive (have not learned to) 1 II cannot at the moment drive, but this is not CAR* connected with my back 2 2 1 have no difficulty driving a car 3 3 A long car journey causes unreasonable discomfort, but shorter trips are not particularly uncomfortable 4 4 1 cannot take long car journeys, and should stop every |-1 hour for a rest, even shorter trips are unpleasant. 5 5 1 can only drive locally because of discomfort 6 6 I cannot drive at all because of discomfort 85-86 Riding in a car or bus 0 0 1 have no difficulty 1 II have difficulty getting in or riding but not due TRANSPOR* to my back trouble 2 2 1 find it hard to get in or out of a car or bus, but riding is fairly comfortable 3 3 1 find getting in and out fairly easy, but travelling is uncomfortable 4 4 1 find both getting in and out difficult and riding uncomfortable 5 5.1 avoid travelling in a car or bus whenever possible because of difficulty Children or grandchildren at home - mark that most 0 appropriate 87-88 1 0 No children under fifteen at home 1 I am able to work and play with them and to help care for them CHILDREN* 2 2 I have to be careful they're not too rough; I 3 cannot lift them 3 I can do little with them - only talk or read or 4 play very easy games 4 I cannot share activities with them at all. Sleep 0 0 I sleep normally most nights 89-90 1 1 I often have difficulty in getting to sleep because of discomfort SLEEP* 2 2 I often have difficulty in getting to sleep but don't know why 3 3 I wake up early because of discomfort and cannot get enough sleep 4 4 I wake up early and cannot get enough sleep but don't know why 5 5 Another illness of mine interferes with my sleep 6 6 I cannot sleep because of illness or upset of another person in the family 226. One month Now before fusion In General 91-92 o o I enjoy life 1 1 I enjoy life, but quite a bit less than I did before this back trouble arose LIFE* 2 2 This back problem is enough to spoil things for me most of the time 3 3 Life is only just tolerable because of this back (or leg) discomfort 4 4 I have even thought of suicide because of this problem 5 5 My enjoyment of life is more affected fay other problems Some other questions 93-94 Any major abdominal surgery 0 None 1 Surgery for ulcer in stomach or duodenum ABDOMEN* 2 Gall bladder operation 3 Kidney or bladder or male organs 4 Female organs 5 Because of injury -6 Bowel surgery 7 Two of the above 8 Three of the above 9 Four of the above •95-96 Stomach trouble (mark only one) 0 No trouble 1 Occasional indigestion or heartburn - no medication . DYSPEP needed 2 Fairly frequent indigestion or heartburn - I take stomach medicines. 3 Quite bad indigestion or heartburn - I've had to have treatment from a doctor 4 Diagnosis of ulcer made by the doctor, and treatment given '5 I've had treatment in hospital for an ulcer once (but not surgery) 6 I've had treatment in hospital more than once (but not surgery) 7 I've had a bleeding ulcer 8 I've had a perforated ulcer 9 I've had surgery for my ulcer 97-93 Skin diseases Seldom or never 1 Psoriasis 2 Frequent rashes or itching now I've had problems with my skin since childhood. SKIN* o 227. FSTIi.lATICW OF RESULTS RESULT Rate- on the line below with a single stroke of VOUT pen the success of your last fusion operation. Extremely poor. Extremely good 228. Back Surgery Form Dr. Kokan - Dr. V/ing Date, of examination \2 Hospital 3-8 Patient's chart number .*. DVA, Pension or WC3 number 9-10 Age in years at examination AGE a-12 Age in years at last fusion. AFUSION 13-14 Age. in years at onset of symptons.... ASYMPTOM Time lapse onset/fusion in months LAPSE 15 Sex 1 Male GENDER 2 Female 16 Place of birth 0 B.C. BIRTHPL* 1 Canada other than B.C. 2 United Kingdom 3 Northern or Western Europe 4 South,Central or Eastern Europe 5 Middle. East (eg.Israel, Lebanan, India) 6 Far East (eg.Chinese, Japanese) 7 British Commonwealth 8 America (U.S.) 9 Other 17 Cultural background (of parents, grandparents or of childhood surroundings) 0 North American 1 French or French Canadian ETHNIC 2 British (would include Commonwealth) 3 Mediterranean (Italian, Spanish etc. include S.America) 4 Indian, Pakistani or similar 5 Chinese, Japanese or similar 6 Northern or Western European 7 Central or Eastern European 8 African 9 Other 18. Education 0 Illiterate 1 Incomplete primary EDUCAT 2 Complete primary 3 Incomplete secondary 4 Complete secondary 5 Trade or business training 6 Professional training not included in 5 7 University - bachelor's degree or similar 8 University - further training beyond bachelor's degree 9 Other 229. Occupation 19-20 Professional or equivalent Time of fusion Now 0 0 Not in this category- OCCUPA 1 1 Medical, dental, veterinary, osteopathic 2 2 Legal (include jurists) 3 3 Architect 4 4 . Engineering (at consultant or design level) 5 5 Teaching 6 6 Government (senior position, department head etc.) 7 7 Major executive in commerce 8 8 High rank in military field, police or transport fields 9 9 Other professional or equivalent 21-22 Technical, skilled, clerical 0 0 Not in this category 1 Paramedical - nurses, technicians, OCCUPB 1 2 2 Banking (management or supervising) 3 3 Creative writers (authors, journalists etc) and performing artists'. 4 4 Photographers, artists, sculptors, commercial artists. 5 5 Salesmen (excluding major executives and sales clerks) 6 6 Clerical 7 7 Skilled workers, servicing (e.g.electrician,plumber) 8 8 Agricultural (farmers, forestry, fishing,. hunting) 9 9 Police & military personnel except highest ranks 23-24 Others 0 0 Not in this category 1 Sales clerks OCCUPC 1 2 2 Production workers (manufacture or assembly) 3 3 Transport or vehicle operators and ancillary personnel 4 4 Construction workers 5 5 Catering and ancillary personnel 6 6 Housewife 7 7 Unskilled labour 8 8 Student 9 9 Other not categorised - please specify. •25—26 Occupation changes most recently Before fusion After fusion 0 0 None (no change) CHANGOC 1 1 Promotion in a similar job 2 2 Change, to a different job, as advancement 3 3 Change to a different job for reasons other than illness 4 4 Change to a different job because of back disability 5 5 Change to a different job because of other illness 6 6 Cessation of employment for age retirement 7 7 Cessation of employment because of back disability 8 8 Cessation of employment because of other reasons. 230. -28' . Number of job changes 29. Time loss in last 2 years Before fusion After fusion 0 - None 0 0 None. 1 Less than 1 week JOBNO 1 1 1 2 Less than 1 month LOSS 2 2 2 3 Less than 2 months 3 3 3 4 Less than 4 months 4 4 4 5 Less than 6 months 5 5 5 6 Less than 1 year 6 6 6 7 Less than 18 months 7 7 7 8 Less than 2 years 8 8 8 9 Unemployed 9 9 More than 8 30 Time off work prior to last fusion 31. Time of return to work after last (or operation if no fusion) Fusion (or operation if no fusion) 0 N> operation 0 No operation PRIOR 1 Less than 1 month 1 Less than 1 month RETURN 2 Less than 2 months 2 Less than 2 months 3 Less than 4 months 3 Less than 4 months 4 Less than 6 months 4 Less than 6 months 5 Less than 1 year 5 Less than 1 year 6 Less than 2 years 6 Less than 2 years. 7 Less than 4 years 7 Less than 4 years 8 Less than 10 years 8 Less than 10 years 9 More than 10 years 9 More than 10 years 32 Religion 0 No definite views 1 Atheist FAITH* 2 Jewish 3 Roman Catholic 4 Buddhist 5 Hindu 6 Mohammedan 7 Other Oriental 8 Specific protestant seat or denomination 9 Other 'protestant' (include here Church of England etc.) -33 Activity in religious life 0 Never „ 1 Once-twice yearly ACTIYE 2 'Occasional' 3 Regular attender at a place of religion (twice monthly or more) 4 'Deeply religious' 5 Active in organisation of particular church 6 Minister of particular church 7 Considered a religious person, but does not take part in an organised church 231. 34-35 Avocation One month before fusion Now 0 0 None HOBBY* 1 1 'Athletics, competitive 2 2 Athletics, non competitive 3 3 Major sports (running, skiing, cycling, swimming) 4 4 Minor sports (walking, jogging, hunting, golf,fishing) 5 5 Creative (indoor, lighter work) 6 6 Domestic maintenance, gardening, house care, etc. Family History 36 Number of siblings of father 37. Father and siblings of father with back troub.V 0 None 0 None Father UNCLE 1 1 EXUNCLE 1 2 2 2 1 sibling of father 3 3 3 2 siblings of father 4 4 4 3 siblings of father 5 5 5 4 siblings of father 6 6 6 1*2 7 7 7 1*3 8 8 8 1 + 4 9 More than 8 9 .1+5 38 Number of siblings of mother 39. •Mother and siblings of mother 0 None 0 None 1 1 1 Mother AUNT 2 2 EX AUNT 2 1 sibling of mother 3 3 3 2 siblings of mother 4 4 4 3 siblings of mother 5 5 5 4 siblings, of mother 6 6 6 1 + 2 7 7 7 • 1+ 3 8 8 8 1 + 4 9 More than 8 9 1 + * SIBS Number of patient's siblings Number with back trouble.... SIBBACK 40-41 Number of children 42. Number of children with back trouble At time of OR PAIN (now) fusion Nov; 0 None OFF(F)(N) 0 0 None 1 1 1 1 1 2 2 OFFBACK 2 2 2 3 3 3 3 3 4 4 • 4 . 4 4 5 5 5 5 5 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 More than 8 9 More than 8 232. 43. Nu-ubcr of children with leg pain, «rheu,matism& or 'growing pains'i (now) 0 None QFFRHEU 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 More than 8 44 Smoking habit 0 Non smoker 1 Mainly cigarettes less than 10 daily SMOKE* 2 Mainly cigarettes less than 20 daily 3 Mainly cigarettes less than 40 daily 4 Mainly cigarettes more than 40 daily 5 Mainly pipe - moderate smoker 6 Mainly pipe - heavy smoker 7 Mainly cigar - moderate smoker 8 Mainly cigar - heavy smoker 9 Combination • fairly heavy 45 Alcohol usage 0 Teetotaller (abstainer) 1 Occasional drink - special occasions only BOOZE* 2 Occasional drink at home or social occasions 3 Drinks once or twice most weeks, in moderation 4 Drinks every week at least once as a major part of the evening's entertainment Has an alcohol drink of some sort daily, may or may not drink more at times 6 Probably relies on alcohol beyond normal social use 7 Early alcoholic 8 Unequivocally alcoholic 9 Ex-alcoholic, or member of AA 46 Drug use mark highest grade 0 None Occasional soft drug user DRUG* 1 2 Frequent or habitual soft drug user 3 Has had a conviction related to soft drugs 4 Occasional non-medical user of stimulants or tranquillisers 5 Frequent non-medical user of stimulants or tranquillisers 6 Occasional opiate or similar user 7 Addict to opiate or similar drug 8 Ex-addict of opiate or dimilar drug 9 Other - specify 233. 47 Other disease states (requiring major in or outpatient treatment) 0 None 1 C.N.S. (excluding psychiatric care) DISEASE* 2- Respiratory 3 Cardiovascular 4 Gastrointestinal excluding peptic ulcer disease 5 Genitourinary. 6 Musculoskeletal 7 . Two of above 8 Three of above 9 Four of above 48 Psychiatric care or personality disorder 0 Normal 1 Moderate or freauent tranquilliser use i.",\Y."~ 2 Had psychiatric attention prior to fusion 3 Has had psychiatric attention since fusion 4 1 + 2 5 1 + 3 6 2 + 3 7 1+2+3 8 Currently in psychiatric ward 9 Other 49 History of trauma related to onset of back trouble 0 None 1 Minor (lifting, a twist) RTRAUMA* 2 Fall from a low height 3 Fall from a greater height 4 Major injury - fracture 5 Repeated stress or minor trauma 6 War injury or similar (blast, G.S.W. etc) 7 Auto accident 50 History of other trauma prior to onset of symptoms but unrelated 0 None OTRAUMA* 1 Lower limb fracture in sports or similar accident 2 Auto accident without fracture or major injury 3 Auto accident with fracture or major injury "4Bast, GSW, or similar 5 Fall from a low height 6 Major fall 7 Two of above •8 Three of above 51 Residual disability from other trauma (50) 0 No residual DISABIL 1 Mild residual discomfort or disability 2 Moderate residual discomfort or disability - unperisioned 3 Severe residual discomfort or disability - unpensioned 4 Moderate residual discomfort or disability - pensioned 5 Severe residual discomfort or disability - pensioned 234. 52 Total number of hospital admissions 53. Total number of operations on back for back 0 None 0 None ADMISS 1 1 1 1 OPERATE 2 #o» 2 2 3 3 3 3 4 4 4 4 5 5 5 5 6 6 6 6 7 7 7 7 8 8 8 8 9 More than 8 9 More than 8 54 Total number of fusion operations 55. Total number of laminectomies 0 None 0 None FUSIONO 1 1 1 1 2 2 2 2 LAMINECT 3 3 3 3 4 4 4 4 5 5 5 5 6 6 6 6 7 7 7 7 8 8 8 8 9 More than 8 9 More than 8 57 56 --Nuraber-ef .refusions of any level Complications of any and all back operations 0 None 0 None 1 1 1 Wound infection (deep) COMPLICA* REFUSION 2 2 2 Wound infection (superficial) 3 3 3 Hematoma 4 4 4 Root damage or irritation 5 5 5 Pseudarthrosis 6 6 6 Shock 7 7 7 Chest or abdominal problems 8 8 8 More than 1 of the above (specify) 9 More than 8 9 Other 58 Complications of last fusion operation 0 None 1 Wound infection (deep) COMPLICB* 2 Wound infection (superficial) 3 Hematoma 4 Root damage, or irritation 5 Pseudarthrosis 6 Shock 7, Chest or abdominal problems 8 More than 1 of the above (specify) 9 Other 235. 59 General appearance - most predominant feature 0 Normal, healthy 1 Very muscular, not overweight GENERAL* 2 Overweight for height 3 Appears very thin 4 Pale, unhealthy looking 9 Other 60 Blood Pressure 61. Weight in kilos WEIGHT 0 Normal 1 Less than 40 (under 88 lbs) 1 Low (systolic less than 100 mm) 2 41-50 (89-110 lbs BP*. 2 High (diastolic over 90 mm) 3 51-60 (111-132 lbs) 3 Very high (diastolic over 120 mm) 4 61-70 (133-154 lbs) 5 71-80 . (155-176 lbs) 6 81-90 (177-198 lbs) 7 91-100 (199-220 lbs) 8 101-110 (221-242 lbs) 9 More than 110(more than 293 lbs) -2 Height in centimetres 1 less than 120 (under 4' ) 2 121 - 130 (4'0» - 4'3") HEIGHT WEIGHT CODE 3 131- 140 (4'3^" - 4'7") FATFACT* = 4 141- 150 (4'7|" - 4'11") HEIGHT CODE 5 151 - 160 (4'11|" - 5'3") 6 161 - 170 (5'3i" - 5'7") 7 171 - 180 (5'7l" - 5'11") 8 181 - 190 .(-5-sii^--.6-«3*) 9 More than 190 (more than 6'3") 63 ENT ENT* 64 Chest 65 Heart 0 normal 0 normal 0 normal 1 abnormal (specify) 1 abnormal (specify) 1 abnormal (specify) 2 not done 2 not done 2 not done CHEST* = 64+65 (i.e. abnormality of either). 66' Abdomen 0 Normal 1 Obese TUMMY* 2 2 or more scars 3 Hernia of any type 4 1 + 2 5 1 + 3 6 2 + 3 7 1 + 2 + 3 8 Other more serious abnormality requiring referral 9 not done 236. 67 Rectal 0 Normal 1 Fissure and/or hemorrhoids RECTAL* 2 Coccygeal tenderness . 3 Abnormality of prostate, sacrotuberoua ligament or other deep structure(specify) 4 1 + 2 5 1 + 3 6 2 + 3 7 1 + 2 + 3 8 Other more serious abnormality requiring referral 9 Not done (this should not be marked1.) 69 Normal 1 Limping R.leg GAIT* 2 Limping L. leg 3 Difficulty in both legs 4 Unable to walk £ Unable to stand i Other - specify 70 Stance 71 Pelvic Tilt 0 Normal 0 Normal' STANCE* 1 List to right 1 Right side up TILT* List to left 2 2 Left side up 3 List forward 4 List backward 9 Other (specify) 72 Lumbar curve 73 Paravertebral muscle tone 0 Normal lordosis 0 "Normal PVTONE*' 1 Exaggerated lordosis .1 Right paravertebral muscle spasm CURVE* Flattened lordosis 2 2 " Left paravertebral muscle spasm 3 Kyphosis 3 1 + 2 4 Scoliosis convex to right 9 Other - specify 5 Scoliosis convex to left 6 1 + 4 7 1 + 5 8 2 + 4 9 2 + 5 74 Abdominal muscle tone 0 Normal 86 fair ne ABDTONE* J J*? ' . *? + 2 Not obese, but poor tone 3 Obese, poor tone 237. 75 Cervical soine ranp,e of motion 0 Normal for age CERVICA* i Limited flexion 2 Limited extension 3 Limited tilt and/or rotation to right 4 Limited tilt and/or rotation to left •51 + 3 6 1 + 4 7 2 + 3 8 2 + 4 9 Virtually or completely ankylosed 76 Cervical spine -other CERVICA and CERVICB 0 Normal combined as 'NECK(O)1 r „ 1 Posterior muscle abnormal tone 2 Tenderness on axial compression (over vortex) 3 Localised tenderness over cervical spine 4 1 + 2, 5 1 + 3 6 2 + 3 7 1+2+3 9 Other (specify) 77 Upper Limbs (either) 0 Normal ARMS* 1 Limitation of shoulder movement 2 Crepitus in shoulder region on motion 3 Neurological impairment of some type in limb i|f. J^. T. £r\. 5-1+3 6 2 + 3 71+2+3 9 Other (specify) 78 Thoracic spine 79 Lumber spins'. ROM flexion Measure C7 tc 0 iformai- Sj. difference in £5ls. THORACIC* 1 Abnormal curve (specify type) LUMFLEX 0 More than 8 cms 2 Limited rotation 1 7-1 - 8 C313 3 Marked tenderness (specify where) 2 6-1 - 7 cms 4 1 + 2 3 5-1 - 6 cms 5 1 + 3 4 4-1 - 5 cms 6 2 + 3 5 3-1 ' - 4 cms 7 1+2+3 6 2-1 - 3 cms 9 Other - specify 7 1-1 ~ 2 cms 8 Less than 1 cm 80 Flexion expressed differently '81 Spasm on Flexion (of paravertebral 0 Touch toes muscles) FLBXTWQ 1 Belw SPASM None mid tibia 1 Moderate 2 Mid tibia • 2 Marked 3 Touches knees 4 Mid thigh 5 0° 238. 82 Lumbar r.nj.ro PCM ox to union 83 Pain on extension PAINEXT LDMEXT 0 Normal 0 No 1 20 - 30° 1 Yea 2 10 - 20° 3 Lees than 10° 84 ROM Rj^ht Flexion 85 ROM left flexion I.FLEX* O Normal 0 Normal RFLEX* 1 30 - 45° - Knee joint 1 30 - 45° Knee joint 2 15 - 30° - Lower thigh 2 15 - 30° Lov/er thigh 3 Less than 15° - Uid thigh 3 Loss than 15° - Mid thigh 0° U 0° RLFLEX .is. the .recombination, .of. RFLEJC+. LFLEX. 87 Passive .Hyperextension test 88 Leg length 0 Full passive hyperextension pain Equal LENGTH* HYPEREXT freo 1 Gives slight pain at normal 1 Right shorter by 1-5 cms. - limit 2 Right shorter by 5-19 cms. 2 Mild pain on hyperextension' 3 Right shorter by over 10 cms 3 Moderate pain 4 Loft shortsr by 1-5 cms. 4. Severe pain - relieved by flexion 5 Left shorter by 5-19 cms. 5 Gives pain not eased on flexion • 6 Left shorter by over 10 cms. Indicate cause. 89 Peripheral ionises •» lov.er limbs 90 Hipj HIPS* 0 Normal O Normal PULSES* 1 Mild decrease) right 1 Right abnormal ( specify ) .2 . Marked decrease' right , 2 Left abnormal ( specify ) 3 Mild docreaso left 3 14 2 , ( specify ) 4. Marked decrease left 5 Mild bilateral decrease 6 More marked bilateral decrease 91 Knees 92 Ankles 0 KNEES* Normal 0 Normal ANKLES'* 1 Right abnormal ( specify) 1 Right abnormal ( specify) 2 Loft abnormal ( specify) 2 Left abnormal ( specify) 3 IH" 2 ( specify ) 3 1+2 ( specify ) LIMB is' the recombination of HIPS + KNEES + ANKLES (normal limb versus abnormal), ' + RFOOT + LFOOT (over) 239. 93 Right foot 94 Loft foot 0 Normal 0 Normal .*FOOT* 1 Abnonnality of arch LFOOT* 1 Abnormality of arch 2 Hallux valgus 2 Hallux valgus 3 Claw or hammer toes ± calluses 3 Claw or hammer toes 1 calluses 4 1 + 2 4 1 + 2 5 1 + 3 5 1 + 3 6 2 + 3 6 2 + 3 7 1+2+3 7 1+2+3 9 Other (specify) 9 Other (specify) 95 Sacroiliac strcs3 (Gaenslen's test) 96 Straight leg raising pain 0 Normal 0 None(normal) GAENSLEN* 1 Right positive SLR* 1 Right 0-30 degrees 2 Left Positive 2 Right 30 - 60 3 1 + 2 3 Right 60-90 4 Left 0-30 5 Left 30 - 60 6 Left 60 - 90 7 Both legs 0-30 8 Both legs 30 - 60 9 Both legs. 60 - 90 97 Bowstring sign (pressure over taut 98 Muscle wasting more than 2 cms popliteal nerve) 0 None BOW* 0 Negative bilaterally 1 Right thigh WASTA* V 1 Positive left o T.~ft t ""*> .2 Positive .i'ighi j 3 bilaterally positive 4 Left calf 5 1 + 3 6 2 + 3 7 1 + 4 8 2 + 4 9 Other - specify 99 Mu a cle wastin g-cont inued 100 Abdominal - able to lift straight legs 0 None in this group 10 era off table? WASTB* i Right extensor digitorum brevis 0 Yes 2 Left » " " 1 No ABDPOWA 3 Right anterior calf muscles 4 Left anterior calf muscles 5 1 + 3 .62 + 3 7 1 + 4 8 2 + 4' 9 Other - specify WASTAB is total number of positive entries in WASTA and WASTB. 101 Ability to life upper body off tabic - leg3 secured 0 ABDPOWB Normal - fairly caoily 1 With difficulty - all the way 2 Moderate difficulty - only part way 3 Marked difficulty - only just able to move 4 Unable to rise off table 240. 102 Back able to lift buttocks off tablo when supino BACKPOW 0 Yes - normally and easily 1 With some difficulty remains extended 2 Moderate difficulty - cannot sustain it 3 Marked difficulty - unable to raiue buttocks froa table 103 Mn Flexors 104 Hip extens ors 105 Hip a bductors L R L R L R 0 0 Grade 5 0 0 Grade 5 0 • 0 Grade 5 1 1 Grade 4 - 1 1 Grade 4 1 1 Grade 4 2 2 Grade 3 2 2 Grado 3 2 2 Grade 3 3 3 Grade 2 3 3 Grade 2 3 3 Grade 2 4 Grade 1 4 4 Grade 1 4 4' Grade 1 5 5 No function 5 5 Ho function 5 . 5 No function 106 Hip Adductors 107 Knee Ex ten sors 108 Knee flexors L R L R L R 0 0 Grade 5 0 0 Grade 5 0 0 Grado 5 1 1 Grade 4 1 1 Grado 4 1 . 1 Grade- 4 2 2 Grade 3 2 2 Grade 3 2 2 Grade 3 J 3 Grado 2 3 3 Grade 2 3 3 Grade 2 4 Grade 1 4 4 Grado 1 4 4 Grade 1 5 5 Ho function 5 5 Ho function 5 5 Ho function .10.9 .Foot dcrsi 110 . Foot f]. ant •nrflBTOTfl 111 Foot Evertors T> JLI R L R L 1. 0 0 Grade 5 0 0 Grado 5 0 0 Grade 5 1 ' 1 Grade 4 1 1 Grade 4 1 1 Grade 4 2 2 Grado 3 2 2 Grade 3 2 2 Grade 3 3 3 Grade 2 3 3 Grado 2 3 3 Grade 2 % Grade 1 4 4 Grade 1 4 4 Grade 1 5 5 Ko'function 5 5 Ko function 5 5 No function 112 Great toe extension 113 Great toe flexion L R L R 0 0 Grade 5 0 0 Grade 5 1 1 Grade 4 1 1 Grade 4 2 2 Grado 3 2 2 Grade 3 3 3 Grade 2 3 3 Grade 2 Grade 1 ft 4 Grade 1 5 5 Ho function 5 5 Ko function. LEGPOW is total score of all limb weakness measures. 114 Deep tendon reflex - knee 115 Deep tendon reflex - a' 0 Normal O Normal DTRKHES* 1 Right increased DTRANK* n . Right increased 2 Right decreased 2 Right decreased 3 Right absent 3 Right absent 4 Left increased 4 Loft increased 5 Left decreased 5 Left decreased 6 Left absent 6 Left absent 7 Both increased 7 Both increased 8 Both decreased 8 Both decreased 9 Both absent 9 Both absent 241 . 116 Plantar reflex 117 Abdominal reflex 0 Normal 0 Normal PLANTAR* j_ Rirht ABDFLEX* 1 Absent right upgoing 2 Absent left 2 Left upgoing 3 Absent both sides 3' Both upgoing 4 Abnormal because of local disease 118 Cremaster reflex 119 Sensation right-level of impairment 6 Normal 0 None CREMAST* 1 Absent right SENSR* 1 L3 2 Absent left 2 14 3 Absent both side.s 3 L5 4 Abnormal because of local disease 4 SI 5 S2 •6 More than 1 root (specify) 7 Peripheral nerve loss - specify 120 Type of loss (right) 121 Sensation left-level of. Impairment 0 No loss 0 None LOSSR* 1 Conforms well to dermatome indicated 1 L3 SENSL* 2 Does not conform to expected dermatome 2 L4 L5 3 Hyperesthesia 3 SI 4 Hypo or anesthesia 4 S2 5 1 + 3 5 6 1 + 4' 6 More than 1 root (specify) 7 2 + 3 7 Peripheral nerve loss •• spc :ify .82 + 4 9 Other (specify) 122 Type of. Ioss _(left| 0 No loss LOSSL* 1 Conforms well to dermatome indicated LOSSRL is combination of 2 Does not conform to expected dermatome two sides. 3 Hyperesthesia 4 Hypo or anesthesia 5 1 + 3 6 1 + 4 7 2 + 3 8 2 + 4 9 Other (specify) 123 Most prominent site of tenderness -TENDERONr * 0 None - 1 Spinous process 2 S.l. joint right 3 S.l. joint left 4 Right buttock 5 Left buttock 6 Right paravertebral muscles (specify level) 7 Left paravertebral muscles (specify level) 8 Greater trochanter (specify sido) 242. 124 Secondary site of tenderness 0 None TENDRTWO* i Spinous process TENDER is a combination: normal/ 2 S.l. joint right one place tender/two sites tender. . 3 S.l. joint left 4 Right buttock 5 Left buttock 6 Right paravertebral muscles (specify level) 7 Left paravertebral muscles (specify level) 8. Greater trochanter (specify side) 9 Other, specify • 125 Spinous process tenderness level (if not localised, give central level) 0"" No spinous process tenderness TENDLOC i B 2 L2 3 L3 4 L4 5 L5 6 SI 7 Over a spinous process but obviously more superficial in scar 9 Other - specify 126 Motivation for surgery 0 No surgery MOTIV* 1 Patient demanded it 2 Patient initially refused it "3 Surgeon'suggested it, after "failure of considerable conservative therapy 4 Surgeon strongly suggested it, after little conservative therapy 9 Other - specify 127 Patient's opinion of surgery (last operation only) 0 No surgery OPINION* i Permanent definite improvement 2 Permanent partial improvement 3 No improvement 4 Temporary improvement for less than 2 years 5 Temporary improvement for a longer period of time 6 Some worsening 7 Definitely worse 9 Other - specify 128 Under the same circumstances, the patient would now; AGAIN* . ? J° SUfSery ' ,< — 1 Accept surgery again 2 Refuse surgery again 3 Undecided 243. 129 Patient's understanding of main reasons for surgery 0 No surgery 1 Does not know - purely on surgeons recommendation 2 To relieve pain 3 To prevent further trouble 4 To improve weakness ' - 5 To improve back function ^ 9 Other - specify • 130 Examiner's_ opinion 0 Mo surgery OBJECT* Patient definitely improved ;- ' 2 Patient partially improved $ 3 Worsening as a result of surgery 4 Worsening as a result of progressive disc disease 5 Worsening as a result of emotional disease 6 Worsening as a result of some other disease 7. Temporary improvement, now worsening 9 Other - specify Surgeons preoperative diagnosis? 131 Pathology found at surgery (last .operation) 0 No operation PATH* 1 No abnormality seen . " 2 ' Bulging disc 3 HSnisted disc • : 4 Pseudarthrosis 5 Fibrosis and scarring in canal 6 Congenital ''an 132 Kigitjjlft. .vs**tg;brae or instability 133 Pathological examination 0 Neither -0 No surgery MICRO* KISS* " 1 Kissing spines (specify level) 1 Normal disc tissue 2 Vertebral instability 2 Degenerative disc 3 Both'of above 3 Not available 4 No discectomy 5 No tissue examined 9 Other - specify Orthopaedists' Rating of Psychological factors? All ratings are done on a 7-point continuum from least to most. 134 In your relationship Introvert 12 3 4 5 6 7 Extravert • ' OVERT Introvert = shy,• withdrawing, socially uncomfortable 135 Dependent 12 3 4 5 6 7 Independent Dependent = subject- seems to get some sort of emotional OPEND gratification and clings to you like a child might. 244. 136 Passive - Aggressive not at all 12 3 4 5 6 7 very much so P.A. «= (very much so) - po.ti.ent complies with your requests OPA that apparently displease him, but you get the impression he's "getting back at you" by not complying fully. 137 Submissive 1 2 3 4 5 6 7 Dominant OPOWER Submissive = patient acceptingly goes along with all your requests, allows you to initiate topics Dominant = patient tri.es to ' steer' parts of the discussion i examination 138 Eagerness in recounting his troubles OBITCH little 12 3 4 5 6 7 very. 139 Emotionality in recounting troubles (is he like a bleeding-heart) little 12 3 4 5 6 7 very OBLEED 1/iD Anxiety in approaching you as as authority or father figure little 12 3 4 5 6 7 very much OANXIETY 141 Anxiety in the stage or course of his pathology little 12 3 4 5 6 7 very rauch SANXIETY little - indifference 142 Estimate of verbal ability low 1 2 3 4 5 6 7 high OWORD 143 Estimate of I.Q. IQ has a mean of 100, standard deviation of 15. low (70) 1 2 3 t 5 6 7 high 130 OTRUTH tnomal average1 Cold toloranoa time ...... soconds. CT1* State right or left hand HANDED Comment on patient's reaction 245. Back Surgery Study - Xray Assessment. Dr. Peter Wing. Patient l.D. Column. Card 1 2 Hospital 3-8 Record Number D.V.A., W.C.B. or other number •••• 9-13 Xray number • H Number of vertebrae NUMBER* 1- 4 distinct lumbar vertebrae 2- 5 * • • 3 - 6 • • 8 4. - incomplete transition of a sixth lumbar vertebra. 5 - hemivertebra Describe anomalies: 15 Sacral anomalies SACRAL* o - none 1 - congenital Describe: 2 - acquired 16 Separate facet epiphyses FACETS* o _ none A - U 1 - Ll 5 - 15 2 - L2 6 - SI 3 - W 7 - a combination - specify. State side, whether superior or inferior facet: 246. Column 17 Scoliosis SCOLIOS* 0 - none Describe and measures 1 - 10-20° 2 - over 20° 18 Spondylolysis - specify aide LYSIS* 0 - none 4 - L4 1 - Ll 5 - L5 2 - L2 6 - SI 3 - L3 7 - other 19 Spondylolisthesis - specify type by cause if possible. LISTHES-" 0 - none seen 1 - grade 1 2 - grade 2 3 - grade 3 4 - grade 4 20 Osteoporosis PROSIS 0 - none seen 4 - grade 4 1 - grade 1 5 - grade 5 2 - grade 2 6 - localised osteopenia - specify. 3 - grade 3 21 Fracture FRACTURE* 0 - none Describe type and level. 1 - probably old. 2 - probably new 247. Column 22 Myelogram dye DYE 0 - none seen 1 - few drops 2 - moderate amount 23 Evidence of laminectomy ( posterior with bone removal - describe), LAMINEGT* 0 - none seen 4 - U 1 - Ll 5 - L5 2 - 12 6 - SI 3 - L3 7 - Combination - specify. 24 Evidence of fusion FUSION* 0 - none seen 5 - anterior interbody 1 - posterior bone block 6-1+2 2 - Boucher's type 7 - 1 +• 4 3 - posterolateral 8 - other combinations - specify 4 - apophyseal screws 9 - other types - specify Also separated into different types of fusion (FUSI0N1, FUSI0N2, FUSI0N3, etc.) 25 Level of fusion LEVEL* 0 - no fusion 5 - L4 5 1 - L5S1 6 - L3 5 2 - L4S1 7 - L3 4 3 - L3S1 9 - other specify. LEVELA Number of segments fused. 4 - L2S1 LEVELB No recombination. 26 Solidity of fusion SOLID (0 - no fusion - n°t used) 1 - solid fusion 2 - pseudarthrosis. (at either level, if two are fused) Specify level (s) and criteria. 248. Column 27 Screws number present SCREWS 0 - none U 1- 1 5 5 2- 2 6 6 3- 3 7 more than 6 28 Screws abnormalities. SCREWED* 0 - none 1 - normal 2 - bent 3 - broken 29 Schmorl's nodes 0 - none Specify level and describe SCHMORL 1 - one site 2 - more than one site 30 Knutsson's sign 0 - not seen KHUTSSON 1 - L5S1 only 2 - other sites - specify 31 Posterior .joint degeneration 0 - none Specify site(s) and side. DEOEN 1- 1 level, 1 side 2- 1 level, bilateral 3 - more than 1 level. 249. Column 32 Traction spurs of anterior longitudinal ligament SPURS 0 - none 1 - present at 1 site 2 - present at more than 1 site Specify levels and position. 33 Osteophytes OSTEOPHY 0 - none 1 - localised 1 site 2 - more than 1 site Detail sites. 34 Ligamentous calcification. LIOCALC 0 - none 1 - localised 1 level 2 - more than 1 level Specify position and site. 35 Kissing vertebral spines ( Baastrup's phenomenon ) BAASTRUP 0 - none Specify levels. 1- 1 level 2- 2 levels 3- 3 levels U - U levels 36 Other skeletal pathology e.g. Paget's, Ca. SKELEX 0 - absent 1 - present 250. Column LANGLE 37-39 Lumbosacral angle - degrees. front back Disc height P B 40-43 DISCI L12 44-47 DISC2 L23 48-51 DISC3 L34 52-55 DISC** U5 56-59 DISC 5 L5S1 DISCMEAN mean of all paired measurements (i.e. both front and back recorded). Posterior joint subluxation in mm. above .joint-body line. 60-61 LUXl L12 62-63 LUX2 123 64-65 LUX3 L34 66-67 LUXlf U5 LUXMEAN mean of Retrospondylolisthesis ( in mm, measured posteriorly). 68 RETR01 L12 69 RETR02 123 70 RETR03 71 RETROD L45 72 L5S1 RETROAVC mean of all levels. Interpedicular distance in mm. 73-74 IPED1 Ll 75-76 IPED2 L2 77-78 IPED3 L3 79-80 IPED4 U 9-10 IPED5 L5 IPEDAVO mean of all levels. 251 . Column Sagittal diameter of canal In mm. 11-12 SAG1 Ll 13-14 SAG2 L2 15-16 SAC3 L3 17-18 SAGft U 19-20 SAG5 L5 21-22 SAG6 SI SAGMEAN mean of all levels Body Height Front Back F B BODYl L 1 B0DY2 L 2 B0DY3 L 3 BODYlt L U B0DY5 L 5; BODYMEAH mean of all paired measurements (both front and back measurable). 252. APPENDIX 2. PSYCHOLOGICAL DATA COLLECTION FORM For details of the psychological data analysis and variable refer to WILFLING279. 253. BACK STUDY FORMAT ** PSYCHOLOGY ** WILFLING Spaces Code Datum Name Date of Exam. (3) Subject # (1) Sex Male 1 Female 2 Date of Birth / I (2) Blank (2) Age in years (2) -.Position in birth order, from oldest. (1) Position in birth order, if: 1 oldest 2 intermediate 3 youngest 4 • only child (2) • Province of birth 0 not Canada 6 Quebec 1 B. C. 7 KB 2 Alberta 8 NS 3 Sask. 9 PEI It Manitoba TIO Nfld 5 Ontario 11 NOT , (1) Size of conmunityS grew up in ( use estimate of size if several moves - most important between 10 and leaving home): 1<500 6 10,000 - 25,000 2 500 - 1,000 7 25,000 -100,000 3 1,000 - 2,500 8 > 100,000 k 2,500 - 5,000 9 can't estimate, many moves '5 5,000 - 10,000 (2) _____ Occupation of father: 0 no father 1 farmer ( owner ) 2 own small business ( like corner store) 3 own large business k professional ( lawyer, Doctor, engineer, etc) 5 semi-professional ( teacher, accountant ) 6 clergy 7 salesman • 8 blue-collar ( clerk, agent, etc.) 9 minor supervisor ( working ) 10 Bervice employee 11 laborer 12 unemployed 13 other lk major supervisor / 254. Spaces Code Datum (1) Parents religious? 0 Ho 1 very 2 moderately 3 a little k one parent no, other 1 or 2 5 very moral, but not religious (only if given spontaneously. (2) How did parents get along? 1-70 scale (2) How happy was childhood? 1-70 scale Any member of family "sickly"? Indicate in separate columns up 8) to 3 of : (1) 0 none 5 grandparent 1 father 6 uncle, aunt 2 mother 7 cousin 3 same sexed sib 8 unrelated member of household k opp. sexed sib (2) • At what age did S leave home permanently? ( years ) (2) _____ Number of years of grade school completed (1) ______1 Number of years University (2) _____ 2 months of vocational school (l) 3 years of apprenticeship (l) _____ In the three above, indicate completeness: 0 didn't do any of 1-3 1 completed 2 incomplete, withdrew ( quit with little roason) 3 incomplete, was ejected k moved down in order above and completed 5 " ". " " " " didn't complete 6 moved up in order above and completed 7 " " " " " " didn't complete . 8 withdrew due war, lack of funds 9 withdrew due health, emotional reasons (l) _____ What was favorite subject in school ? ( code below ) (l) ______What was most disliked subject in school ? 0 can't answer 1 math 2a science 3 English or a language k history/geography. 5 clerical 6 shop work, agriculture, home economics 7 eports 8 art -painting, music, drama 9 other 255. XXj Datum Religiousness 0 never have been religious 1 I- always have been religious 2 . have changed to more religious 3 have changed to less religious k remained religious, but changed faiths Service 0 none 1 WV/2 didn't see battle 2 VW2 did see battle 3 Korea didn't see battle 4 Korea did see battle 5 -both, didn't see battle 6 both, did see battle 7 peacetime forces only Present martial status: ^ , 0 single 3 separated 1 ' married 4 divorced 2 widowed 5 common-law Past marital record ( excluding the above); 0 nothing to add 6 three or more separations 1 one divorce 7 one past comnon-law wife 2 two divorces 8 two or more past common-law 3 widowed once- or more wives 4 . one separation 9 refuses to talk 5 two separations Status of present marital relationship: 0 there isn't one 1 ready to break up 2 would break up if not for children 3• stormy but will remain intact 4 • indifferent 5 about average 6 above average 7 superb 9 refuses to discuss Sex life . 0 not exposed to one 1 little interest, mutual 2 little interest, spouse frigid or impotent 3 little - spouse has other difficulty 4 little - S not interested ( frigid or impotent) 5 little - because of S's back 6 little - because of S's other.troubles 7 moderate - mutual 8 moderate - spouse's lack of interest 9 moderate -.spouse's other troubles 10 . moderate - S's lack of interest 11- moderate - S's back ... 12 moderate - S's other troubles 13 All's well 14 refuses to discuss. 256. Spaces Code Datum (l) Number of children at home now 0-9 9=9 or more (l) _____ Does S support anyone else ? (1) 0 no (l) 1 parent or grandparent 2 " " " of spouse 3 sib k sib of spouse 5 removed relative 6 " "of spouse 7 child of relative 8 child of spouse's relative 9 unrelated child or adult (l) • Does S own home or apartment ? 0 no 1 yes, large mortgage > $ 10,000. 2 yes, moderate mortgage 5-10,000 3 yes, small mortgage < 5»0C0 4 yes, clear title (1) _ . Has S ever owned a home ? ~~ 0 no 1 yes - had to give it up for financial reasons 2 yes - gave it up because of other difficulties 3 yes - gave it up for sake of. convenience (2) _____ Income to S's family per month in $ 100's ( Gross ) (l) ______Source of income (l) 0 no income ( for sources 2,3,) (l) ______1 business ownership 2 investments 3 S works 4 spouse works 5 pension 6 parents 7 • children 8 welfare 9 S, won't say (l) _____ Does £> think that personality or psychological status can have a bearing on the existence of or the experience of a back problem ? 0 no yes,,a little yes, a moderate amount self reference J 3 yes» quite a bit not now, but used to have a bit not now, but used to have a moderate amount not now, but used to have a lot to do with it 7 not for self, but for others a bit 8 not for self, but for others a lot 9 _ will not give a direct answer Elaborate on back if j3 thinks psych, status effects him 257. Code Datum Has S ever hsd psychiatric attention ? 0 no 1-8 9° 9 or more times DSM-2 codes for major disorders ( let 000 = no disorder ) When first psych, attention ? ( years ago ) When last psych, attention ? ( years ago; 0= K. 1 yr. or none) Has anyone in S's family had psychiatric attention ? 0 no 1 grandparent 2 parent 3 sib lr- spouse 5 offspring 6 removed blood relative 7 in-law 8 unrelated " family" member ______ DSM-2 codes for the immediately above, in order given. How does S feel about taking part in this study? 0 no response 1 "• great dislike 2 minor dislike 3 indifferent k glad to help 258. APPENDIX 3. COLD TOLERANCE TEST PROCEDURE In a bowl of suitable size, in this case, a two-gallon plastic bucket, enough water is placed to three-quarter fill the vessel. A standard tray of ice is added and the whole thing covered with a cloth and allowed to equilibrate for perhaps twenty or thirty minutes. It should really be standardized with a thermometer. Instructions to the Patient It should be kept standardized to keep the motivational aspect of the instructions constant. The patient's dominant hand should be used for the study and he should not be encouraged to talk while the study is in progress. Instructions should be standardized and might be as follows: "Different people feel different amounts of pain and I would like you to try a simple test of this. I would like you to immerse your dominant hand up to the wrist in this bowl of ice water. Keep your hand palm down and with the fingers open. Keep your hand in the water as long as you can reasonably bear it but not to the point of suffering unreasonable pain. While your hand is in the water think about sensations in your hand and after you have taken it out you can tell me about these. 259. Okay, go ahead, and remember to keep your hand in the water as long as you can." The time should be recorded in seconds. No patient should be allowed to keep his hand in the water for more than three minutes as after this time he may develop an anesthetic-type of response and the time will not be reliable while the patient himself may suffer harm. It may be of interest to record the patient's response on the left hand and right hand but the dominant hand should be noted and should probably be done first otherwise a learning synonym will be incorporated. 260. APPENDIX 4. PSYCHOLOGICAL SCALES CALIFORNIA PERSONALITY INVENTORY SCALES - NAMES AND IMPLICATIONS96 The California Personality Inventory is designed to assess "normal" functioning, especially social functioning, rather than to screen out the "abnormal" personality. 1. Do (dominance). 2. Cs (capacity for status). Drive, ability to communicate. 3. Sy (sociability). Social activity, popularity. 4. Sp (social presence) 5. Sa (self-acceptance) 6. Wb (sense of wellbeing). Health and vitality, feeling of physical fitness. 7. Re (responsibility). Responsibility, positive character integration. 8. So (socialisation). "Good citizens" vs. "bad citizens". 9. Sc (self-control). Lack of impulsiveness. 10. To (tolerance). Fairmindedness and humanitarianism vs. fascism, authoritarianism. 11. Gi (good impression). Creation of a good impression, strong correlation with K scale of M.M.P.I. 261 . 12. Cm (communality). Dependable, practical, has common sense vs. is at odds with himself 13. Ac (achievement via conformance). High school grades, effi• ciency . 14. Ai (achievement via independence). Self-reliant, independent in judgement, able to think for himself. 15. Ie (intellectual efficiency). High correlation with intellectual assessments. 16. Py (psychological-mindedness). 17. Fx (flexibility). Flexibility vs. rigidity. 18. Fe (feminity). Correlates well with MMPI MF scale. MINNESOTA MULTIPHASIC PERSONALITY INVENTORY SCALES - NAMES AND IMPLICATIONS93 THE VALIDITY SCALES "L" scale - lie scale. The subject wishes to 'appear good' by answering in the negative when questioned regarding (for example) a socially undesirable mannerism common to all. Must be considered with clinical scales. "F" scale - indicates carelessness or lack of understanding or cooperation. Item always answered in a particular direction. Known as 'Fake' scale as subjects wishing to put themselves in a bad light 262. will show a high score here. "K" scale - represents defensiveness as a test-taking attitude is incorporated as a correction in some of the clinical scales. K is correlated with socioeconomic status and amount of education. It may be useful clinically in that a lower K score indicates willingness to accept treatment situations. THE CLINICAL SCALES 1. (Hs). Known as hypochondriasis formerly, but better thought of as index of the importance of bodily functions and symptoms to the particular person. May show undue concern about health, or complain about pain and disorders which are hard to find and for which no clear organic basis can be found. Elevated in those with demonstrable physical disorder, a score over 65 suggests ex• aggeration. 2. (D). Reflects the characteristics of depression, may be ele• vated in those with severe organic illness or with insight into a mental illness. Combination with elevated score on F suggests suicidal risk. 3. (Hy). Hysteria. Those with high 3 scores are more immature psychologically than any other group. Under stress they are likely to develop physical symptoms. The neurotic triad (scales 1, 2 and 3) from the most 263. notable feature of the profile in the patient with illness of a dominantly hysterical pattern. The "conversion V" refers to ele• vation of 1 and 3 with 2 lower. Operative and other radical phys• ical treatment of patients whose profiles show a conversion V as a feature of an elevated neurotic triad should only be undertaken after careful evaluation of all possible psychological factors and functional components. Scale 3 may be low in the occasional patient when his conversion symptom is "working" or manifest. (Pd). Psychopathic deviate. These people are marked by the absence of deep emotional response, inability to form warm per• sonal attachments and disregard of social mores. Likely to be higher in adolescents and young adults and low in the strictly religious. (Mf). This is a measure of masculine or feminine interest patterns, a high score indicating a tendency towards interests usually associated with the opposite sex. Initially derived from a group of homosexuals (not necessary practicing), the scores for college men, for example, are somewhat higher than other groups, with seminary students and those in artistic and literary fields scoring highest. (Pa). Paranoia. Extreme elevations on this scale are most likdy to be observed in paranoid schizophrenia; . persons with an ex• cessive amount of paranoid suspiciousness are common and in many 264. situations not especially handicapped. However, persons receiving high scores on this scale have to be handled with special care. False negatives may result if a paranoid person wishes to conceal his disability: an abnormally low score may result. (Pt). Psychasthenia. A high score on this scale reflects com• pulsive or phobic traits. This correlates highly with scale 8. (Sc). Schizophrenia. This scale measures the similarity of the subject's responses to those of patients who are characterised by bizarre and unusual thoughts or behaviour. It distinguishes about 60% of observed cases diagnosed as schizophrenia, but does not identify some paranoid types of schizophrenia (which usually score high on 6) and some with a pure schizoid type of behaviour. Simple schizophrenics are more likely to obtain a generally ele• vated profile with scale 1 high. A high score on scale 8 in a clinically normal individual is consistent with a 'withdrawn' person, who does not come into severe adverse contrast with his environment. High 8 scores should be evaluated in the light of the other scales. (Ma). Mania. The scale measuring the personality factor char• acteristic of persons over-productive in thought and action. The borderline between normal and abnormal is wide, and other scale elevations must be taken into consideration in its interpretation. A high 9 scale may be an asset to a person who wishes to be ex- trovertive and active. 265. THE RESEARCH SCALES In this study three scales not included in the clinical scales have been used. Si. (Social introversion-extroversion). A popular scale, high scores being indicative of introversion or avoidance of social contacts with others. Es. (Ego-strength). Of use in and developed as a predictor of favorable response to psychotherapy, this scale includes items concerning physical functioning, stability, personal adequacy, phobias. Lb. (Low back pain). Constructed on the basis of 25 MMPI items which differentiated between patients with low back pain diag• nosed to be due to a protruding intervertebral disc (the "organics") and those whose low back pain had not been diagnosed as resulting from an organic disease (the "functionals"). The "functionals" had a conversion V pattern (see scale 3) with a secondary peak as scale F; the mean "organic" profile showed nearly equal scales 1, 2 and 3 slightly higher than the rest of the profile. A high score on the Lb scale is suggestive of "functional" low back pain. A "cutting point" of 70 (T score) is used clinically to 106 place the individual patient into the appropriate group; HANVIK found a high degree of reliability in the scale. 266. APPENDIX 5. THE BECK INVENTORY OF DEPRESSION 267. HAMEJ D.I.t si A. 0 I do not feel sad 1 I feel blue or sad 2a I am blue or sad all the time and I can't snap out of it 2b I am so sad or unhappy that it is very painful 3 I am so sad or unhappy that.I can't stand it B. 0 I am not particularly pessimistic or discouraged about the future 1 I feel discouraged about the future 2a I feel I have nothing to look forward to 2b I feel that I won't ever get over my troubles 3 I feel that the future is hopeless and that things cannot improve C 0 I do not feel like a failure 1 . I feel like I have failed more than the average person 2a I feel I have accomplished very little that is worthwhile or that means anything' 2b As I look back on my life all I can see is a lot of failures 3 I feel I am a complete failure as a person ( parent, husband, wife) D. 0 I am not particularly dissatisfied la I feel bored most of the time lb I don't enjoy things the way I used to 2 . I don't get satisfaction out of anything anymore 3 1 am dissatisfied with everything E. 0 I don't feel particularly guilty 1 I feel bad or unworthy a good part of the time 2a I feel quite guilty 2b I feel bad or unworthy practically all the time now 3 I feel as though I am very bad or worthless F. 0 I don't feel I am being punished 1 I have a feeling that something bad may happen to me 2 I feel I am being punished or will be punished 3a I feel I deserve to be punished 3b • I want to be punished G 0 I don't feel disappointed in myself la I am disappointed in myself lb 1 don't like myself 2 I am disgusted with myself 3 I hate myself H 0 I don't feel I am any worse than anybody else 1 I am very critical of myself for my weaknesses or mistakes 2a I blame myself for everything that goes wrong -2b I feel I have many bad fault3 268. I. 0 I don't have any thowhts of harming myself 1 I have thoughts of harming myself but I would not carry them out 2a I feel I would bo better off dead 2b 1 have definite plans about committing suicide 2c I feel my family would be better off if I were dead 3 I would kill myself if I could J, 0 1 don't cry any more than usual 1 I cry more now than I used to 2 I cry all the time now„ I can't stop it 3 I used to be able to cry but now I can't cry at all even though I want to E. 0 I am no more irritated now than I ever am 1 I get annoyed or irritated more easily than I used to 2 I feel irritated all the time 3 I don't get irritated at all at the things that used to irritate me L. 0 I have not lost interest in other people 1 I am less interested in other people now than I used to be 2 • I have lost most of my interest in other people and have little feeling fx>r them 3 I have lost all my interest in other people and don't care about them at all M» 0 I make decisions about as well as ever 1 I am less sure of myself now and try to put off making decisions 2 I can!t make decisions anymore without help 3 I can't make any decisions at all any more H. 0 I don't feel I look any worse than I used to 1 I am worried that I am looking old or unattractive 2 . I feel that there are permanent changes in my appearance and they make me look unattractive 3 1 feel that I am ugly or repulsive looking 0, 0 I can work about as well as before la It takes extra effort to get started at doing something lb I don't work as well as I used to 2 I have to push myself vary hard to do anything 3 I can't do any work at all P» 0 I can sleep as well as usual 1 I wake up more tired in the morning than I used to 2 I wake up 1-2 hours earlier than usual and find it hard to get back to sleep 3 I wake up early every day and can't get more than 5 hours sleep Q. 0 I don't get any more tired than usual 1 I get tired more easily than I used to 2 I get tired from doing anything 3 I get too tired to do anything 269. R. 0 My appetite is no worse than usual 1 My appetite is not as good as it used to be 2 My appetite is much.worse now 3 I have no appetite at all anymore S. 0 I haven't lost much weight, if any, lately 1 I have lost more than 5 pounds 2 I have lost more than 10 pounds 3 I have lost more than 15 pounds T, 0 I am no more concerned about my health than usual 1 I am concerned about aches and pains or upset stomach or constipation or •other unpleasant feelinrs in my body 2 I am so concerned with how I feel or what I feel that it's hard to think of much else 3 I am completely absorbed in what I feel XSa 0 I have not noticed any recent change in my interest in sex 1 I am less interested in sex than I used to be 2 I am much less interested in sex now 3 I-have lost interest in sex completely 270. APPENDIX 6. THE KILPATRICK-CANTRIL SELF-ANCHORING SCALE (modified appropriately) 271 . Put the K-C sheet in front of the subject and give the following instructions verbatimt This is a self-perception scale. What I would like you to do is to think for a moment what for you would be an ideal life situation. Tfaat I mean by this is» what are your goals, aspirations - what would you like to attain in life that would make you happy? After you've thought it over for a minute, would you please give me a brief description over here? ( indicating with pencil). After that I would like you to stop and think of what for you would be the very worst life situation. By this I mean a set of circumstances that you could• imagine yourself being-in, but that you-most, certainly wouldn't, want to be a part of. After you've thought.-it over .for a minute, would you please give a brief description of those circumstances in these spaces? ( indicating with pencil). After you've done that, we'll come over here ( indicating with pencil) and look at this ten-step ladder figuratively as the ladder of life., with the ideal life situation at the top and the worst life situation at the bottom. I'll ask you to show me where on the ladder you are now, where on the ladder you were just before your back problem started, and finally where on the ladder you think you'll be in 5 years from now. Right now, though, I'd just like you to thick about and describe the ideal life situation and the worst life situation for you ( indicating with pencil), and then we'll do the rest together.n It is a good practice to absent oneself from the room for about 5 minutes at this time, because most subjects try to talk during the task. Before leaving make certain the subject understands the task and as .non-directively as possible ansvver specific questions or overcome objections. 272. Returning after about 5 minutes' absence ( the time taken to smoke a cigarette), wait unobtrusively if necessary, for the subject to complete the task and then continue : "Okay. Now, if we come over here to the ladder ( indicating with pencil) and regard it as the ladder of life with this ( indicating written description), the ideal life situation at the top, and this ( indicating written description) the-worst life situation,•at the bottom, could you show me with an arrow on the (subject'I left of the ladder ( making a sweeping motion with the pointer pencil so a point is not suggested)where you are now." After the arrow is placed by the subject, ask him to write 1972 ( the present year) beside, it. Then continue t "With another arrow, could you show me where on the ladder you were just • before your back problem started." After the arrow is placed, ask the subj ect to label it with the year his back problem started. And finally, ask: "And finally, could you show me with another arrow where you think you'll be on the ladder in 5 years from now." Label the final arrow with the year 5 years hence ( i.e. in 1972, label 1977).