Osteophytes in the Osteoarthritic Hand: Their Incidence, Size, Distribution, and Progression

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Annals ofthe Rheumatic Disases 1991; 50: 627-630 627 Ann Rheum Dis: first published as 10.1136/ard.50.9.627 on 1 September 1991. Downloaded from Osteophytes in the osteoarthritic hand: their incidence, size, distribution, and progression

J C Buckland-Wright, D G Macfarlane, J A Lynch

Abstract osteophytes at the marginal and capsular sites of Quantitative microfocal radiographic assess- each joint in wrists and hands. Progression in ment of osteophytes in osteoarthritic hands the number and area of osteophytes was showed that their number and area were assessed and their distribution in the wrist and greatest at joint margins, in the dominant hand with time was studied. hand, in the second and third compared with fourth and fifth phalanges, in the third phalanx, and in the second distal inter- Patients and methods phalangeal joint respectively. These sites cor- Forty five patients were recruited, of whom 32 respond with those for the largest forces (three male, 29 female; mean age at first visit 62 exerted in the hand: the dominant side, the (SD 10) years; mean disease duration 11-6 (SD finger tripod used in the precision grip, power 10) years) completed the full 18 months of the grip, and pulp-pinch respectively. The greater study. All had evidence of two of the three osteophytosis on the trapezium of the non- following features in the hands on conventional dominant first carpometacarpal joint was radiography: subchondral sclerosis, joint space probably related to forces exerted during narrowing, and osteophytes. Sixteen patients power grip. Osteophytes increased signifi- had interphalangeal nodes on entry, defined as canty in number and area during the 18 one visible swelling on one joint plus three or month study period. more palpable swellings on other hand joints. By the end of the study 25 of the 32 patients had nodal osteoarthritis of the hands. All were Osteophytes are the classic radiographic and carefully examined to exclude other forms of pathological hallmark ofoste6arthritis, but their arthritis and all were seronegative for rheuma- role as the sole diagnostic marker of osteo- toid factor and had a normal erythrocyte sedi- arthritis is questioned' as they also correlate mentation rate. They were allowed to continue with age.2' The presence of osteophytes in taking their normal drugs. Patients were x rayed most experimentally induced models of osteo- on entry and every six months for 18 months. http://ard.bmj.com/ arthritis, in many species of animals, however, Stereopair macroradiographs (x5) were supports the contention that osteophyte for- prepared of the right and left wrists and hands mation is a component of the osteoarthritic of each patient. The hand was placed in a degenerative process.5 In patients with osteo- stereotactic unit positioned close to the source arthritis osteophyte size has been reported to and displaced by 6 mm between each x ray increase with progressive structural disorganisa- exposure.'3 The details of this procedure and its on September 28, 2021 by guest. Protected copyright. tion of their joints.4 6 In osteoarthritis of the accuracy are described elsewhere. 1417 The hand osteophytes are characteristically seen in stereopair macroradiographs thus obtained were the distal and proximnl interphalangeal (DIP, examined under a large format stereoscope PIP) joints. The incidence of osteophytes in (Ross Instruments, Salisbury, UK) for three these joints has been explained in terms ofpinch dimensional evaluation of the joint struc- v grasp actions of the hand.7 Investigations have tures.'3 'S The right hand, back illuminated found that textile workers employed for at least carriage of the stereoscope comprised a digitiser Department of Anatomy, 20 years in pinch operations were more prone to tablet linked to an MOP-videoplan (Carl Zeiss, United Medical and DIP joint degeneration than winders, whose Hertfordshire, UK). A cross wire cursor was Dental Schools of Guy's to the in the macro- and St Thomas's actions and osteophyte formation affected the used outline osteophytes Hospitals, wrist.8 9 It was suggested that the mechanical radiograph overyling the digitiser. A detailed Guy's Campus, hypothesis is not always consistent as the first description of the method of measurement and London SEI 9RT carpometacarpal (CMC) joints of the non- its accuracy in recording x ray features is J C Buckland-Wright dominant were more J A Lynch hand affected than those in reported elsewhere.'4 Department of the dominant hand.9" In the wrist the sites of osteophyte develop- Rheulmatology, This study undertook a detailed assessment ment occurred adjacent to the insertion of the United Medical and of the distribution of osteophyte formation capsule and interosseous ligaments. In the Dental Schools of Guy's were and DIP and St Thomnas's using microfocal radiography. The results metacarpophalangeal (MCP), PIP, Hospitals, compared with reports on the pattern of force joints the bones were subdivided on the basis of Guy's Campus, distribution in the hand. The advantages of osteophytes occurring at the juxta-articular London SEI 9RT margin insertion on both the D G Macfarlane high magnification and resolution offered by or pericapsular microfocal radiography'2 13 provide not only medial and lateral surfaces of the bones in digits Correspondence to: Dr Buckland-Wright. detail of x ray features approximating to his- 2-5 (fig 1). From the macroradiographs data on Accepted for publication tology'3 but also accurate quantitative evalu- the number and area in square millimetres of I August 1990 ation'4 of the incidence, size, and distribution of osteophytes at each of the sites in both the right 628 Buckland-Wrigh, Mafarlane, Lynch

the hand and wrist of all 32 patients. In general, Ann Rheum Dis: first published as 10.1136/ard.50.9.627 on 1 September 1991. Downloaded from few osteophytes were present in the wrist apart from the first carpometacarpal (CMC) joint where osteophytes were present in 27 (84%) patients. Their mean area was much larger than at any other joint in the wrist or hand, though the mean number of osteophytes was similar to that of individual PIP joints (table 1, fig 2). The mean number and area of osteophytes in the hand and wrist was greater on the dominant than the non-dominant side (table 1). In particular, their area was significantly greater in the DIP and PIP joints of the dominant hand. In the wrist there was no difference between the extremities apart from those on the bones of the first CMC joint. Here, the mean osteophyte area was but not Figure I Diagram ofthe bones ofthe wrist, larger, statistically significant, in metacarpophalangeal, andproximal interphalangealjoints, the non-dominant hand (table 1). Only at the illustrating the sites at which measurements ofosteophyte trapezium of the non-dominant hand was the number and area were carried out. For clarity the arrows osteophyte area twice as large (14-4 (SD 27-2) indicating the marginal sites in the wrist have been omitted. mm2) and significantly different (p<0048) from that on the dominant hand. and left hands of all patients were recorded Comparison of the extent of osteophyte for- separately for the radiographs obtained on the mation in the separate horizontal groups of four visits. The data initially recorded on the joints showed that their greater mean number MOP-videoplan were transferred to an IBM and area occurred in the DIP joints, followed by PC/AT microcomputer. A standard format was the PIP and then MCP joints in a ratio for used in this file for each patient/hand/visit osteophyte area of about 3:2: 1 respectively. The record, enabling comparison ofdata both within difference between the three groups was signifi- and between patients. The analysis was carried cant (p<0-05) for both number and area, apart out with the SPSS/PC+ statistics package'8 and from osteophyte number between the DIP and some specially written Fortran programs. PIP joints of the dominant hand. The Wilcoxon test was used to compare the Between the separate phalangeal rays the difference in number and area of osteophytes in the hand between the groups of joints (DIP, PIP, and MCP), between the separate phalangeal rays, and between individual joints. Within

each joint the same test was applied to deter- http://ard.bmj.com/ mine the difference in the number and area of osteophytes between those at the margin and capsular attachment, between the ulnar and radial sides, and between the proximal and distal sides of the joint. Osteophyte progression during the study was calculated from the change

in mean osteophyte number and area at the on September 28, 2021 by guest. Protected copyright. separate regions as well as for the wrist and hand. The significance of any differences was calculated using the Wilcoxon matched pairs test.

Results The first radiograph taken at the start of the study showed that osteophytes were present in

Table I Mean (standard deviation) of osteoptyte number and area in dominant and non-donant hands and wrists ofpatients at start ofstudy. The signiftcance ofany difference between the twvo extremities is indicated by an asterisk Joint affected Number of osteophtes Area of osteophytes (mm2) Dominant Non-dominant Dominant Non-dominant Wrist and hand 28-7 (11-8) 26-0 (11-6) 62-0 (46-8) 59-4 (40 9) Hand only 24-5 (11-2) 21-9 (11 1)* 452 (446) 33-2 (309)** DIPt 11-2 (4-5) 10-8 (4-7) 21-8 (27-3) 16-6 (17-9)* PEPt 9-4 (5-8) 7-2 (5.4)*** 16-2 (19-0) 11-0 (14-9)** MCPt 3-9 (4-2) 3-9 (4-0) 7-2 (9-8) 5-6 (7-5) First CMCt 1-5 (1-6) 1-8 (1-5) 10-6 (18-7) 20-1 (31-7) Wrist 1-8 (1-7) 2-3 (2-1) 6-2 (9-1) 6-1 (8-5) Test used: Wilcoxon matched pairs. Significance level set at p=005. *p<0o03; **p<0-02; Figure 2 Diagram ofthe bones ofthe wrist and hand ***p

Table 2 Mean (standard deviation) ofosteophyte number and area in phalangeal rays and mean osteophyte number and area in the joints Ann Rheum Dis: first published as 10.1136/ard.50.9.627 on 1 September 1991. Downloaded from the significance of differences between the rays of the second and third rays was about twice as Osteophyte Significance of differences (p value) large as those in the fourth and fifth rays (table 2). The joints of the third ray had the greatest Ray Number Area (mm2) Rays Number Area number and area of osteophytes. Among 2nd 6-4 (3-3) 12-2 (13-1) 2nd-3rd <0-02 NS individual joints, the second DIP joint was the 3rd 7-6 (4-1) 14-2 (14-8) 2nd-4th <0 0003 <0 0001 4th 4-6 (2-8) 6-1 (8-9) 2nd-Sth <01001 <01001 single most affected hand joint (fig 2). Within 5th 4-6 (3-3) 5-7 (7-9) 3rd-4th <010001 <010001 the joints ofthe fourth and fifth rays osteophytes 3rd-5th <010001 <010001 4th-Sth NS NS occurring at the fifth DIP joint tended to be more numerous and larger. Statistical test: Wilcoxon matched pairs. Significance level set at p=OO5. Comparison between capsular and marginal osteophytes showed that the latter were significantly more prevalent and larger at all of the Table 3 Mean (standard deviation) ofthe number and area ofosteophytes atjuxta-articular joints other than the third and fourth MCP margins (7-A) and capsular (CAP) attachment in the hand joints. The signifcance of the joints (table 3). The extent of osteophyte difference in osteophyte number and area between those at the two sites are indicated in the space between the tw colunns formation on the medial (ulnar) and lateral (radial) sides of the joint showed a more variable Joints Index Middle Ring Liutle pattern. In general, the number and area of J-A CAP 7-A CAP J-A CAP J-A CAP osteophytes tended to be greater on the medial side of the joints, and was significantly so at Number the DIPt 2.5** 0-7 2.5** 0-7 2-0** 0-3 1-9 0-6 second DIP joint, at all the PIP and the second (1-3) (0-9) (1-4) (0-9) (1-4) (0-5) (1-5) (1-0) and third MCP joints, and in area alone at the PIPt 1-8** 0-3 2-3** 0-5 1-6** 0-3 1-4** 0-1 (1-5) (0-7) (1-6) (0-9) (1-4) (0-7) (1-2) (0-4) fourth MCP joint. The exception was the third MCPt 0.9* 0-3 0-8 0-5 0-4t 0-2 0-5tt 0-2 DIP joint in which osteophyte area was signifi- (1-2) (0-6) (1-2) (1-04) (1-0) (0-4) (0-9) (0-5) cantly larger on the lateral (radial) side (table 4). Area (mm2) There was no significant difference between the DIP 5.9** 2-0 4-3tt 2-1 1-8** 0-5 2-3** 1-0 (8-9) (3-5) (7-5) (4-1) (3-3) (1-0) (3-3) (2-1) proximal and distal parts of each joint. Osteo- PIP 2-3** 0-6 3.9** 0-9 1-8* 1-3 1-7** 0-3 phyte area, however, tended to be larger on the (3-5) (2-4) (5-7) (2-1) (3-4) (5-7) (3-2) (1-2) MCP 1-2tt 0-5 1-3 1-3 0-6 0-5 0-4t 0-3 proximal side but only significantly so (p<0025) (2-2) (1-5) (2-7) (3:04) (1-6) (1-5) ([-0) (1[8) in a few joints of the hand-namely, the third Statistical test: Wilcoxon matched pairs. Significance level set at p=005. tP<005; ffp<0-025; and fourth DIP, fourth PIP, and all MCP *p<0.005; **p<0.0002. joints. tDIP=distal interphalangeal; PIP=proximal interphalangeal; MCP=metacarpophalangeal. Over the 18 month period of the study the number and area of osteophytes in the whole wrist and hand increased significantly (table 5). The first CMC joint and the wrist separately Table 4 Mean (standard deviation) of the number and area of osteophytes on the medial (MED) and lateral (LAT) sides ofjoints of the hand. The significance of the difference in showed no significant change. Significant osteophyte number and area between those at the two sides of the joint are indicated in the increases in number were found in the DIP and http://ard.bmj.com/ space between the two colunns PIP joints of dominant and non-dominant joints Index Middle Ring Little hands and the MCP joints of the non-dominant hand. The changes in area were even more LAT MED LAT MED LAT MED LAT MED significant in all the joint groups (DIP, PIP, and Number MCP) for both dominant and non-dominant DIPt 1-2** 2-1 1-6 1-6 1-1 1-2 1-3 1-2 ([-0) (0-9) (1-1) (0-9) (1-0) (0-8) (1-3) (0-9) hands. There was no significant difference in PIPt 0-6** 1-4 2112- 1-7 0-6* 1-2 0 5** 1[1 the pattern ofosteophyte formation between the on September 28, 2021 by guest. Protected copyright. (0-9) (1[2) (1-2) (1-3) (0-9) (1-1) (0-7) (0-9) MCPt 0.4* 0-8 0-5- 0-8 0-2 0-4 0-3 0-4 start and end of the study. (0-6) (1 0) (1-1) (0-9) (0-6) (0-7) (0-7) (0-6) Area (mm2) DIP 3-5t 4-3 3-9tt 2-6 1-2 1-1 1-7 1-5 Discussion (5-3) (5-5) (6-3) (3-5) (2-0) (1-9) (2-3) (2-5) PIP 0-8** 2-8 1-5* 3-2 1-0** 2-1 0-6** 1-9 The correspondence between osteophyte form- (1-9) (5-0) (2-3) (4-9) (2-6) (4-5) (1-7) (3-4) ation and the pattern of force distribution is MCP 0-6* 1-1 0.9tt 1-7 0-3tt 0-8 0-4 0-3 (1-4) (2-1) (2-6) (3-2) (0-9) (1-7) (1-4) (1-0) seen here by the greater number and area of osteophytes in the dominant hand,W9" and on Statistical test: Wilcoxon matched pairs. Significance level set at p=005. 1-p<0-05; ffp<01025; *p<0.005; **P<0-0002. the lateral (radial) side of the hand.9 " Our tDIP=distal interphalangeal; PIP=proximal interphalangeal; MCP=metacarpophalangeal. findings showed that the number and area of osteophytes in the second and third phalangeal rays were twice that present in the fourth and Table S Mean (standard deviation) of osteophyte number and area in dominant and fifth rays. This pattern was consistent with the non-dominant hands and wrists at the end of the study. The significance ofany difference in forces associated with the tripod of finger action osteophyte number and area between the start and end ofthe study is indicated by an asterisk required in precision grip.192' Further, the Jomt affected Number of osteophytes Area of osteophytes (mm2) greatest osteophyte formation occurred within the third phalangeal ray and at the second DIP Dominant Non-dominant Dominant Non-dominant joint, corresponding to the largest forces exerted Wrist and hand 31-4 (11-7)* 29-0(11-8)* 73-2 (50.7)** 67-9(41-1)* across these joints during the actions of power Hand only 27-8 (10.9)* 24-8 (11 1)** 54.7 (47.3)** 41-7 (35-0)** DIP 12-6 (4-2)-tt 12-6 (4.8)* 25-4 (27.2)* 20-2 (17-8)** and pulp pinch grip respectively.22 At the fifth PIPt 10-8 (6.5)* 7.9 (5-5)ft 9.4 (21-4)* 13-7 (19.5)* DIP joint osteophyte number and area were MCPt 4-4 (4-0) 4-4 (3-9)ff 10 0 (I15-1)tt 7-9 (9-6)** 1st CMCt 1-5 (1-6) 1-8 (1-7) 11-9 (23-9) 18-5 (25 9) greater, though not significantly, than at other Wrist 2-1 (1-7) 2-4 (1-9) 6-6 (11-5) 7-7 (14-0) joints in the fourth and fifth rays. This difference Test used: Wilcoxon matched pairs. Significance level set at p=0-05. Itp<0-05; jtp<002; was probably associated with increased load *p<0.005; **p<0-0002; tFor abbreviations see table 1. applied to the fifth terminal phalanx in provid- 630 Buckland-Wright, Macfarlane, Lynch

ing support and balance to the hand during activity, which has led to the particular pattern Ann Rheum Dis: first published as 10.1136/ard.50.9.627 on 1 September 1991. Downloaded from precision movements." The larger number and of osteophyte formation described here. Thus area of osteophytes at the medial borders of the osteophyte formation is not due to abnormal second DIP, all the PIP, and second, third, and forces in joints' but to existing forces exerting a fourth MCP joints was present because these greater load on the subchondral bone owing to joints tend to show an ulnar deviation related to altered mechanical properties of the articular the muscular contraction within the extensor cartilage. expansion.22 This produces an increased mechanical load at the medial joint margin, resulting in increased formation. from This study was supported by a grant trom Ciba teigy rrnarma- osteophyte Apart ceuticals. The authors would like to thank the members of the the second the remaining DIP joints showed a international (Ciba Geigy) for their support and cartilage project M K radial deviation and this was found to be encouragement and in particular Drs B Levis and Jasani. We would also like to thank Mrs B Clark, Mr I Carmichael, and associated with significantly larger osteophytes Mrs H Rees for their assistance. at the lateral margin of the third DIP joint and a tendency for osteophytes to be larger on that side in the fourth and fifth DIP joints. In the wrist the greatest formation 1 Danielsson L G, Hernborg J. Clinical and roentgenologic osteophyte study of knee joints with osteophytes. Clin Orthop 1970; 69: was at the base of the thumb in the non- 302-12. 2 Jacqueline F, Arlet J, Laporte C. La coxite densifiante a dominant hand, confirming earlier obser- evolution benigne. Rev Rhun Mal Osteoartic 1950; 17: vations.9-' 23 In particular, the trapezium had 114-20. an osteophyte area twice that of the dominant 3 Veraguth P C. La tete femorale du veillard; etudes de ses transformations senileset de leurs rapport avec la coxathrose. hand located at the site of the capsular and Rev ChirOrthop 1955; 41 (suppl 1): 39-111. 4 Hernborg J, Nilson B E. The relationship between osteo- lateral colateral ligament insertions. This, we phytes in the knee joint, osteoarthritis and aging. Acta suggest, is probably due to larger forces pro- Orthop Scand 1973; 44: 69-74. duced in these structures in the non-dominant 5 Moskowitz R W. Experimental models of osteoarthritis. In: Moskowitz R W, Howell D S, Goldberg V M, Mankin H J, hand during power grip, such as that used in the eds. Osteoarthritis, diagnosis and management. Philadelphia: wringing action. In the dominant hand the Saunders, 1984: 109-28. 6 Altman R D, Fries J F, Bloch D A, et al. Radiographic intensity of the forces produced in the same assessment of progression in osteoarthritis. Arthritis Rheun region may be less owing to the relatively 1987; 30: 1214-25. 7 Radin E L, Parker H G, Paul I L. Pattern of degenerative greater strength of the fingers in grasping arthritis. Preferental involvement of distal finger joints. objects as in a power grip.22 Lancet 1971; i: 377-9. 8 Hadler N M, Gillings D B, Imbus H R, et al. Hand structure Active bone growth at the joint margins has and function in an industrial setting. Influence of three been noted in osteoarthritis of the hand and patterns of stereotyped, repetitive usage. Arthritis Rhewn 1978; 21: 210-20. knee.4 6 11 Over the 18 months of this study 9 Acheson R M, Chan Y-K, Clementt A R. New Haven survey osteophytes increased significantly in number of joint diseases. XII: Distribution and symptoms of osteoarthrosis in the hands with reference to handedness. and particularly in area, indicating that these Ann Rhewn Dis 1970; 29: 275-86. features are of an active disease process and 10 Sokoloff L. Loading and motion in relation to aging and part of for and

degeneration joints: implications prevention http://ard.bmj.com/ quite distinct from those associated with the treatment of osteoarthritis. In: Helminen H J, Kivaranta I, aging process, which alter in size more slowly. 1- Saamanen A-M, Tammi M, Paukkonen K, Jurvelin J, eds. Joint loading. Biology and health of aidular structures. These findings agree with those of Altman et Bristol: Wright, 1987: 412-24. al,6 who found that osteophytes were the most 11 Dickson R A, Morrison J D. The pattern of joint involvement in hands with arthritis at the base of the thumb. Hand 1979; important feature in identifying and assessing 11: 249-55. the progression of osteoarthritis in the hands. 12 Buckland-Wright J C. A new high-definition microfocal x-ray unit. Br3J Radiol 1989; 62: 201-7. Recently, in a study of this same group of 13 Buckland-Wright J C, Bradshaw CR. Clinical applications of patients with osteoarthritis, we found that high microfocal radiography. BrJ Radiol 1989; on September 28, 2021 by guest. Protected copyright. 62: 208-17.defliition osteophytes and subchondral sclerosis occur in 14 Buckland-WrightJ C, Carmichael I, Walker SR. Quantitative the hands before the radiographic detection of microfocal radiography accurately detects joint changes in rheumatoid arthritis. Ann Rheum Dis 1986; 45: 379-83. joint space narrowing.24 The indications are 15 Buckland-Wright J C. X-ray assessment of activity in that the early response of bone was conse- rheumatoid arthritis. Brj Rhewnatol 1983; 22: 3-10. 16 Buckland-Wright J C. Advances in the radiological assess- quential to the subtle changes in the biochemical ment of rheumatoid arthritis. Br J Rhewnatol 1983; 22 composition and stiffness characteristics of (suppl): 34-43. 17 Buckland-Wright J C. Microfocal radiographic examination articular cartilage; changes that we believe of erosions in the wrist and hands of patients with precede the occurrence of cartilage fibrillation rheumatoid arthritis. Ann Rheum Dis 1984; 43: 160-71. 18 Norusis M J. SPSS/PC+ for the IBM PC/XTIAT. Chicago: followed by loss and narrowing of joint space.24 SPSS Inc, 1986. This supports the earlier suggestion that osteo- 19 Napier J R. The form and function of the carpo-metacarpal joint of the thumb. J Anat 1955; 89: 362-9. phytes are part of the response of bone to 20 Backhouse K M, Hutchings R T. A colour atlas of surface increased mechanical load associated with anatomy clinicat and applied. Netherlands: Wolfe Medical, 1986: 144-69. cartilage degeneration.7 25 Evidence for this was 21 Tubiana R, Thomine J-M, Mackin E. Examination of hand seen here as osteophytes were significantly and upper limb. Philadelphia: Saunders, 1984. 22 Jones A R, Unsworth A, Haslock I. A microcomputer greater in number and area at the joint margins controlled hand assessment system used for clinical than at the and, addition- measurement. Engineer Med 1985; 14: 191-8. capsular attachments, 23 Aune S. Osteo-arthritis in the first carpo-metacarpal joint. ally, there was no real difference between the Acta Chir Scand 1955; 109: 449-56. proximal and distal articular elements of each 24 Buckland-Wright J C, Macfarlane D G, Lynch J A, Clark B. Quantitative microfocal radiographic assessment of pro- joint. In addition to the increased load imposed gression in osteoarthritis of the hand. Arthritis Rheum 1990; on the subchondral bone, by changes in the 33: 57-65. 25 Moskowitz R W, Goldberg V M. Osteophyte evolution: articular cartilage, are the effects of forces studies in an experimental partial menisectomy model. exerted across the hand and wrist during normal J Rheumatol 1987; 14 (suppl 14): 116-9.