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Home , Lumbar spinal stenosis, Neurogenic claudication, Spinal stenosis

CONTINUOUS LEARNING LIBRARY Degenerative Pathology Lumbar Spinal Author: Dr. Marcelo Gruenberg Editor In Chief: Dr Néstor Fiore Senior Editor: Dr Peter Vajkoczy OBJECTIVES

CONTINUOUS LEARNING LIBRARY

Degenerative Pathology Lumbar

■■ To understand basic anatomical and functional considerations in the setting of stenosis of the lumbar canall.

■■ Describe the clinical and radiographic findings, during patient evaluation.

■■ Consider the differential diagnoses that should be taken into account when addressing patients with symptomatic stenosis of the lumbar canal.

■■ Outline treatment options for a given pathology

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 2 CONTENTS

1. Introduction...... 04 5.

Peripheral neuropathies...... 16 2. Anatomy and pathophysiology Intermittent vascular ...... 16 Overview...... 05 Disc herniation...... 16 Summary...... 07 Other pathologies...... 16

3. Clinical evaluation Summary...... 16

Forms of presentation...... 08 6. Treatment Physical examination...... 09 Medical treatment...... 17 Summary...... 09 Surgical treatment...... 19

4. Complementary studies Summary...... 25

X-ray...... 10 References...... 26 Computed tomography...... 11

Magnetic resonance (MRI)...... 12

Sacral radiculography...... 13

Electromyography...... 15

Summary...... 15

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 3 1. INTRODUCTION

Stenosis of the lumbar spine is becoming increasingly prominent as the average Advances in the knowledge of the pathophysiology of spinal degenerative age of our population increases. This is increasingly important due to the increased disease, and in non-invasive imaging studies, such as magnetic resonance (MRI), 1 functional demand of older patients. have contributed significantly to the understanding of lumbar spinal stenosis. Furthermore, advances achieved in surgical and anesthetic techniques have The first well documented descriptions of lumbar stenosis date back to 1893, greatly improved treatment outcomes and reduced complications when Lane (Wiltse, There are currently t is only in the last decade that the first prospective and randomized studies 1991) reported a case of treated surgically. Throughout countless surgical have been published with postoperative follow-up to confirm or disregard some the subsequent 60 years further descriptions were made to this syndrome and its’ alternatives, from selective concepts. related intra-operative findings. In 1954, Verbiest a Dutch neurosurgeon, described microdecom-pressions the symptoms of intermittent and demonstrated its to radiographic relationship to spinal stenosis. plus arthrodesis and instrumentation. Kirkaldy-Willis, Paine, Cauchoix and McIvor (1974) performed an extensive review of publications and discussed the more controversial aspects of a study that is still used as reference on the subject. Some controversy regarding this pathology still persists, as for example, what is the ultimate cause of the symptoms or the need for supplementing decompression with an arthrodesis. These authors proposed a classification that is still valid, which differentiates stenosis from degenerative disease versus from a developmental cause. Reduced anteroposterior and lateral diameter of the lumbar spine is due to developmental alterations and is typically found throughout the lumbar spine. On the other hand, degenerative stenosis occurs at levels with arthritic changes and the canal diameter can be normal between the affected levels. The authors mention mixed stenoses, where both situations are combined, and also mention other less frequent reasons such as post-traumatic or post-arthrodesis stenosis.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 4 2. ANATOMY AND PATHOPHYSIOLOGY

Overview It is important to identify the alteration in the structures leading to spinal stenosis: From a functional viewpoint, lumbar degenerative spinal stenosis can be ■■ 2 understood as a situation of imbalance in the content-container ratio of the The central aspect of the is roofed by the laminae and the vertebral canal. In other words, between the volume taken up by neurovascular ligamentum flavum spans the interlaminar space and attaches on the tissue and the potential area that bone and tissue structures provide to host anterior 2/3rds of the cephalad and the posterior 1/3 of the caudal them. vertebrae. ■■ Laterally, the ligamentum flavum attaches to the lateral aspect of the laminae From a clinical viewpoint, such patients exhibit a syndrome characterized by the at the root of the facet joints (medial pedicle) which marks the lateral aspect onset of the following symptoms: of the spinal canal. ■■ ■■ The lateral wall of the canal spans each level, between the adjacent pedicles, ■■ radiculalgias with an outlet that could be compared to an infundibuliform canal where the larger and medial aperture would be the lateral recess, and the smaller and ■■ neurogenic claudication of the lower extremities lateral extreme defines the foramen. The lumbar spine provides a central canal or spinal canal and another two lateral ■■ The anatomical alterations of the facets frequently occur in two locations: spaces: the lateral recess and the foramen to house the neural elements the superior facet of the caudal vertebra specifically affects the lateral sector of the recess and foramen, while the inferior facet of the cephalad vertebra affects the medial sector or recess, which may also impact the central canal. The narrowing of the spine due to the degenerative processes of ■■ Lastly, the anterior surface of the canal is made up of the following structures: one or more of these sectors may cause compression of the neural elements. This can affect one or several levels simultaneously. ■■ posterior wall of the vertebral bodies Stenosis can, be localized in the central and/or lateral regions ■■ ■■ posterior longitudinal

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 5 In the spine, disc degeneration is the preceding process which is responsible The capacity of the lumbar spine to contain and protect the sacral nerve roots for triggering the anatomical alterations that lead to stenosis. The disc loses can therefore be affected by structural or dynamic anatomical changes (such as the ability to adequately transfer and distribute load, and subsequently pseudospondyliolisthesis, degenerative , laterolisthesis, etc.), all of which compensatory changes occur due to overload of the posterior complex. This depend on the degenerative process described above. overload leads to thickening of the ligamentum flavum and to degenerative The sagittal diameter of the lumbar spinal canal normally ranges between changes in the cartilage and bone between the facet joints. This condition is 16 mm and 18 mm. The reduction to less than 11-12 mm is considered as accompanied by synovitis and, finally, subchondral bone alterations. 2 substantial narrowing. These measurements, however, present large individual variations and a correlation between anatomy and clinical findings should not always be expected. Deterioration of the Mobile Segment The bone structures that cause narrowness are presented below: ■■ hypertrophy of joint processes ■■ posterior of vertebral bodies ■■ aminae thickening ■■ soft tissues ■■ thickening of the ligamentum flavum ■■ joint synovitis ■■ disc protrusion that may intensify a condition of chronic neurogenic Facets Disc claudication

Synovial reaction Circumferential tear Dysfunction Cartilage damage Radial disruption

The physiopathology Capsular laxity Internal disruption of claudication is Anteroposterior due to the conflict of Subluxation Narrowing space in the content- container ratio. Osteophytes Osteophytes Stabilization

Cascade phenomenon described by Kirdaldy-Willis et al. (1974)

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 6 This means that the central narrowing of the spinal canal, primarily associated to hypertrophy of the laminae, ligamentun flavum, and medialization of joint processes, generally manifests as This means that the central narrowing of the spinal canal, primarily associated to hypertrophy of the laminae, ligamentun flavum, and medialization of joint processes, generally manifests as intermittent claudication on walking. On the other hand, stenosis of the lateral or foraminal 2 recesses are related to the superior joint processes and can cause . Direct compression Disc degeneration and alterations in mechanics may lead to of nerve structures or segmental instability and degenerative that causes chronic and compression of perineural relapsing back pain and central or foraminal stenosis. Other causes of segmental vessels leads to vascular instability include scoliosis and . alteration which can cause the symptoms of stenosis and back pain..

Summary: ANATOMY AND PATHOPHYSIOLOGY Lumbar degenerative spinal stenosis can be understood as a situation of content-container ratio imbalance. It is important to identify the structures that border the neural canal. Changes in these structures may lead to spinal stenosis ■■ hypertrophy of joint processes ■■ posterior osteophytes of vertebral bodies ■■ laminae thickening ■■ ligamentum flavum thickening ■■ joint synovitis ■■ superimposed disc protrusion worsening chronic neurogenic claudication

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 7 3. CLINICAL EVALUATION

Forms of Presentation Neurogenic Claudication

Lumbar stenosis presents as a clinical syndrome with some more typical features : Neurogenic claudication is characterized by pain or numbness during activity 3 involving the lower limbs. The spinal canal widens with flexion of the lumbar spine and this is why patients may reporincreased capacity for ambulation while maintaining trunk flexion. Increased ambulation may be helped with the use of a back pain cane or simply by adopting sagittal imbalance typically referred to as “old man’s gait”. Lumbar stenosis Radicular symptoms can be quantified according to walking capacity or distance traveled until onset of claudication. Neurogenic claudication Several scales that attempt to quantify symptoms can be found in medical literature: Japanese Orthopaedics Association (JOA) scale, Oswestry Disability Back Pain Index (ODI), Swiss Spinal Stenosis Questionnaire (SSSQ), Shuttle Walking Test (SWT), etc During the early stages of spinal stenosis, the back pain in the lumbar spine may be mild and intermittent with a mechanical type pattern. During this phase, as with other arthritic joints, pain usually responds to anti-inflammatory . Lumbalgia is the most As the condition progresses, pain increases and response to and other therapies decreases. frequent symptom Symptoms of neurogenic claudication recorded during history A relationship between the lumbar pain and the symptoms of lower extremities appear in lower extremities upon walking taking, but is non-specific is present although very variable in nature. While some patients have equal parts or during prolonged standing. and is not ruled out as lumbar pain and lower extremity pain, in others, the pain is secondary because It improves when sitting. a manifestation of other upon getting up, the lower limb symptoms become most prominent. spinal or extra-spinal pathologies. Radicular Pain Radicular symptoms include pain, numbness, mild and paresis, which are initially asymmetric and exacerbated upon lumbar extension. Dermatomal distribution of symptoms helps identify affected levels, though not always accurately

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Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 8 Physical Examination Summary: Patients may present with bilateral or unilateral symptoms. They can generally flex the trunk without much difficulty. Extension, on the other hand, is problematic and, CLINICAL EVALUATION if sustained, may trigger radicular symptoms for the above reasons. Nerve stretch Clinical presentation of lumbar stenosis can include: back pain, , and tests, reflexes and sensitivity are generally normal or slightly altered, except in claudication. severe cases or when associated to disc herniation or arthrosynovial cyst, in which 3 Degenerative-type back pain with stenosis does not present with specific case radicular may be evident. characteristics. It generally is associated with symptoms in the lower Physiological lumbar is usually reduced; spinal alignment in the standing extremities which may include radiculopathy or claudication. Radicular position is prone to flexion, and extension will be limited. If the patient is made symptoms subside during trunk flexion and patients may report and greater to walk continuously, then the symptoms of neurogenic claudiation may become walking capacity in the flexion position apparent. Physical examination with the patient at rest might not provide too many specific signs; however, in some cases this is essential to rule out an extra- spinal pathology.

A simple physical examination when done correctly will, in some cases, permit ruling out an extra-spinal pathology.

For this, sufficient time should be given to the following actions:

■■ When there are no palpation of abdomen and arterial other other associated ■■ mobilization of and knees pathologies with similar ■■ visualization of muscle masses symptoms, history taking ■■ perform a complete can be more help than physical examination, therefore a point should be made of having a detailed interview with the patient.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 9 4. COMPLEMENTARY STUDIES

X-Rays 4 X-ray images are the first test performed to assess patients with potential lumbar stenosis. It is accessible, inexpensive, and although only bone and calcified tissues can be seen, it provides a global view of the following structures: ■■ bone status ■■ spinal alignment ■■ degree of arthritic involvement

Specifically, the anteroposterior radiograph with patient in a standing position permits the following actions: ■■ assess frontal alignment ■■ detect and quantify scoliosis and/or laterolisthesis ■■ indirectly visualize degenerative changes via reduction of interlaminar spaces and facet hypertrophy

Lateral radiographs allow visualization of the following features: ■■ assess lordosis ■■ detect lysis ■■ identify fractures caused by ■■ establish the association with pseudospondilolisthesis ■■ get get an approximate idea on spinal mobility, due to the degree of disc impingement and presence of osteophytes

Both radiographic views are required to obtain a topographical interpretation of the information provided by more sophisticated tests when in the presence of sacralization or another anatomical variant. Lastly, dynamic X-rays in flexion, extension, and lateralization help detect and measure the existence of instability in both planes. In certain cases, these functional tests are supplemented by MRI, which contributes to the interpretation of the clinical condition. Orthogonal radiographs of a patient with mechanical back painand neurogenic claudication when walking 100 meters are presented on the following page.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 10 4

Asymmetric impingement of several discs (particularly L3‑L4 and L4- L5) can be seen, which determine degenerative scoliosis with lateral osteophytes and laterolisthesis. Marked spondyiloarthropathy can be seen.

Anterior X-ray of the lumbosacral column Lateral X-ray of the lumbosacral column

Frontal plane alignment and laterolisthesis are assessed from the frontal view. The lateral view is important for determining lordosis, visualizing severe facet joint The capacity of computed tomography to accurately define bone tissue deterioration and assessing disc impingement and anterior osteophytosis. These can also be used to assess and measure the vertebral canal; however, it degenerative changes, added to the presence of “short” pedicles at L4 and L5, should be noted that in low resolution tests, other structures such as the permit diagnosing narrowing of the lumbar spinal canal ligamentum flavum, synovial capsule or disc, could be undervalued and be read as a normal vertebral canal even in the presence of significant Computed Tomography compression. This test provides an accurate visualization of bone structures, especially facet involvement. The following observations can be made in thin and correctly orientated sections: The limitations of computed tomography are related to poor discrimination of soft ■■ joint space evaluation tissues inside the canal and to the patient being in the recumbent position that attenuates the changes which occur in a standing position. ■■ identification of subchondral involvement ■■ determination of joint line orientation in the axial plane

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 11 The disadvantage of MRI is that, as with computed tomography, it provides a static image, and sagittal sections are difficult to interpret in patients with scoliosis. The new MRI machines, not yet available in all areas, can assess patients in a standing position and with different degrees of flexion and extension. Preliminary results of this new technology are very encouraging and perhaps the use of intrathecal 4 contrast may be avoided in the future. MRI images of a patient with canal stenosis are presented below.

Laminae with increased thickness, facet joint hypertrophy with stenosis in recesses and foramina can be seen.

Computed tomography at the lumbar level

Magnetic Resonance Imaging (MRI) MRI is the technique of choice to confirm and evaluate stenosis when the interview, clinical examination and the X-rays point towards this diagnosis. MRI shows the dural sac, roots and structures The root can be followed through the recess and foramen using the combination that cause stenosis, of axial and sagittal sections. Compression at L3-L4 and L4-L5 can be seen Also, particularly synovial or degenerative listhesis at L4-L5. ligamentous thickening MRI is indicated for all patients undergoing surgical intervention. and disc alterations. It MRI, T2, sagittal is also useful to reveal When MRI is contraindicated, as in the presence of a pacemaker or neurovascular pathologies such as clip, intrathecal contrast should be used to assess the compression and rule out tumors, infections, etc.. the presence of an intradural tumor.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 12 Sacral Radiculography This test should only be performed in very selected cases and perhaps will not be required in the future; however, most patients with degenerative compressive lumbar pathology report that their symptoms decrease in decubitus and slight 4 lumbar flexion. MRI and computed tomography are done precisely in this position. This position, which reduces lordosis and lack of axial load, increases canal and foramina diameters. These changes, documented in in-vivo and in-vitro studies, could underestimate the degree of lumbar stenosis in some cases.

When the interview and physical examination of some patients point the diagnosis towards stenosis, but MRI and/or CT used in the conventional position do not reveal correlation between clinical assessment and images, then radiculography is indicated.

Laminae with increased thickness, facet joint hypertrophy with stenosis in recesses and foramina can be seen.

Computed tomography at the lumbar level

MRI shows the dural sac, roots and structures that cause stenosis, particularly synovial or ligamentous thickening and disc alterations. It is also useful to reveal pathologies such as tumors, infections, etc..

Severe compression of the dural sac can be observed centrally and in the lateral recesses. The fluid present within the posterior joints should be noted, which are the result of overload in the region.

MRI, T2, axial section

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 13 CLINICAL CASE MRI findings for a patient with right lumbosciatica do not match the severity of symptoms, which included pain in the L5 radicular region and weakness on 4 extension of the right hallux

Compression of right L5 root justifying patient symptomatology is not apparent.

MRI, T1: Left parasagittal and axial sections

The anteroposterior and oblique images of the myelogram clearly showed amputation of left L5 root at recess entry level.

Right L5 root amputation is observed, justifying patient symptomatology.

Sacral radiculography of the lumbosacral region

Response to conservative treatment was negative in this case, and surgical treatment was performed. In spite of all of this, the test is not considered a routine approach. Possible complications and limitations restrict its use to a well selected group of patients previously assessed by CT and/or MRI, without an accurate diagnosis and who are considered candidates for surgical treatment

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 14 Electromyogram

Electromyograms can point towards compromised roots; however, they are not useful for defining the topography of compression or its cause. 4 They are mainly prescribed to rule out peripheral neuropathies and myopathies.

Summary: COMPLEMENTARY STUDIES A simple radiological assessment is accessible, inexpensive, and although only bone and calcified tissues can be seen, it provides a global view of the following items: ■■ bone status ■■ spinal alignment ■■ degree of arthritic involvement

Computed tomography provides accurate visualization of bone structures. The following observations can be made in thin and correctly orientated sections: ■■ joint space evaluation ■■ identification of subchondral involvement ■■ determination of joint line orientation in the axial plane MRI is the technique of choice to confirm and evaluate stenosis when the interview, clinical examination and the X-rays point towards this diagnosis.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 15 5. DIFFERENTIAL DIAGNOSIS

Peripheral Neuropathies Disc Herniation Peripheral neuropathies appear with non-radicular pain. They are generally Radicular pain is generally the predominant symptom in disc herniation. 5 persistent at rest, and do not vary with movements of the lumbar spine. They are Disc herniations occur more frequently in young individuals, the onset is acute accompanied by the following symptoms: and related to effort, movement or posture. Pain irradiation has a defined ■■ areflexia metameric route. It is intensified with the following actions: ■■ hyperesthesia of the skin ■■ Lasegue maneuver ■■ deep sensory disturbance ■■ Valsalva maneuver ■■ trunk flexion A history of diabetes, alcohol abuse, virus disease, etc. helps define the clinical condition, and neurophysiological tests confirm the diagnosis. Findings upon examination are more defined than in the setting of lumbar stenosis .The diagnosis can be confirmed by MRI.

Intermittent Vascular Claudication Other Pathologies In intermittent vascular claudication syndrome, painful symptomatology is more The following less frequent pathologies should be taken into consideration distal than proximal, it does not manifest a defined radicular topography, and during differential diagnosis: pain varies depending on the activity level of the lower extremities rather than ■■ infections movement or position of the lumbar column. ■■ tumors in the pelvic region Physical examination is useful as it may reveal the following findings: ■■ osteoarticular disorders ■■ diminished distal arterial pulses ■■ cold extremities ■■ skin and muscle atrophy Summary: A history of vascular disease, diabetes and smoking, and are generally associated, DIFFERENTIAL DIAGNOSIS and a vascular Doppler ultrasound and assessment by a heart specialist or heart Several processes can generate radicular involvement and simulate surgeon confirm the condition . stenosis. A correct differential diagnosis is possible with appropriate physical examination and guided history taking.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 16 6. TREATMENT

Medical Treatment Kinesiology This is the first therapeutic option that should be considered for all patients Passive forms (short wave, laser, magnet therapy, etc.) may be of use during 6 without motor compromise. the first stages to manage symptoms, but will not change the natural evolution of the disease.

The goal of medical treatment (not surgical) should be to relieve the symptoms and recover functional capacity. Active kinesiology includes the following exercises: ■■ cardiovascular exercises, indicated to improve patient’s aerobic capacity ■■ spinespecific exercises, indicated to achieve the following This is the first therapeutic option that should be considered for all ■■ improve the range of spinal mobility patients without motor compromise. ■■ strengthen paravertebral and abdominal muscles ■■ modify lordosis with muscle exercising and postural advice Medication Non-steroidal anti-inflammatory drugs (NSAID) are first line treatment for lumbar pain and reduced functional capacity of patients. Drug therapy is determined based on the primary symptoms and patient-specific factors which include the following alternatives: ■■ limitations due to digestive intolerance The chronicity of ■■ interaction with other drugs the clinical picture ■■ allergies limits the use of both systemic and opiate derivatives. Consideration should be given to some elderly patients who will need the administration of these drugs to be adjusted to lower doses with the purpose of avoiding adverse effects.Patients may be resistant to multiple therapeutic methods, and this may require varied drug combinations.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 17 In this group of patients, it is important to recognize how physical activity is Computed tomography-guided foraminal injections are usually preferred for limited by age and poor physical condition. unilateral or bilateral foraminal stenosis, and of unilateral or bilateral application, depending on the symptoms. On the other hand, classic is preferred when several levels are affected by stenosis and the segment originating the symptoms cannot be established. To avoid abandonment of treatment, exercising should be done The most frequent of epidural injection is accidental puncture progressively and always under the strict supervision of a qualified 6 of the dura mater which may result in a spinal headache. Bedrest is usually professional. sufficient to control the symptoms in these cases.

Braces The use of a lumbar belt or brace is indicated for the management of pain secondary to facet arthritic processes, or to control stenosis-related instability

Patients with stenosis and scoliosis may also benefit with the use of an orthosis.

When prescribing any of these restraint methods, it is important to know their negative effects and to limit their use over time: ■■ osteoporosis ■■ muscle atrophy ■■ respiratory constraint ■■ digestive disturbances

Epidural or Selective Injectionsns Direct administration of slow release steroids has been used for decades to control symptoms and achieve functional improvement. Although there are no scientifically sound studies in medical literature that clearly establish the effectiveness of this approach, it can be useful in the practice.

The choice of epidural or selective nerve root injections by periradicular route, guided by computed tomography, is established according to the patient’s symptoms.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 18 Surgical Treatment The ideal situation for applying simple decompression would be a patient Surgical treatment is usually indicated for the following situations: without back pain with neurogenic claudication caused by unilateral and monoradicular pain of one lumbar segment that preserves physiological ■■ onset of motor disorders lordosis with normal or reduced mobility due to disc impingement and ■■ invalidating claudication osteophytosis. 6 ■■ radicular pain that does not respond to conservative therapy When indication for surgery is right, the outcome will depend on the correct interpretation of symptoms, on the choice of the most appropriate technique When indicated and executed correctly, simple decompression achieves good and its competent execution results and, in turn, is associated with a low complication rate, particularly The best candidate for Onset of motor deficit disorders or the presence of interacting diseases are not a complications related to surgical duration and bleeding. surgical treatment is contraindication for surgery, but have a negative effect on the final outcome. one in whom radicular, but not yet deficit, symptomatology predominates over Simple Decompression lumbalgia. Several decompression techniques have been described for the central canal and foramina. All of them require appropriate release of neurovascular elements by resection of , synovial, laminae, and hypertrophic sectors of the facets.

The limits of simple decompression should respect the structures required for stability, bearing in mind that the goal of surgery is to achieve effective decompression of the neural elements.

In order to sustain a balance between decompression and stability, only cases without preoperative instability can undergo simple decompression Simple decompression has been performed effectively for over 100 years. The technical aspects of this surgery that have evolved over the years include: ■■ addition of specific surgical instruments ■■ ocular magnification ■■ improved lighting ■■ improved hemostasis ■■ safer anesthetic management The presence of scoliosis, spondylolisthesis or laterolisthesis are relative contraindications for simple decompression. Most important contraindication of decompression alone is hypermobility of sectors that are to be intervened

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 19 CLINICAL CASE 6 Patient with bilateral sciatica and intermittent neurogenic claudication. 200 m walking perimeter. BILATERAL SINGLE FOCAL

The best candidate for Trajectory of surgical treatment is osteotomies one in whom radicular, for releasing but not yet deficit, lateral receses. symptomatology predominates over lumbalgia.

Computed tomography, L4-L5 axial section Stenosis at the level of both lateral recesses between L4 and L5 can be seen.

Frontal sacral radiculography

Articular block was not effective in patient management. Given failure of medical therapies and blocks, selective release surgery of the compressed area is indicated.

Selective decompression at bilateral L4-L5 level (recalibration) can be observed.

Frontal post-operative X-ray (five years following surgery).

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 20 Decompression and Arthrodesis The need for adding arthrodesis is established if preexisting instability it apparent or if decompression has a significant effect on the stabilizing structures. Several studies can be found in the literature such as Abumi et al. (1990) that try to establish, based on cadaver models, what structures and at what percentage 6 they should be preserved during resection. Although useful as general guidance, these studies do not include muscle activity or biological processes of healing wounds. In elderly patients who Therefore, no defined parameter exists that is applicable to all patients, and it is present intercurrent the surgeon who must establish the need for performing arthrodesis either via diseases, the decision during patient examination and review of images or intraoperatively. of adding morbidity Following are some situations that lead to consideration for arthrodesis: by performing ■■ decompression that includes several levels bilaterally arthrodesis can be as decisive as the surgical ■■ listhesis in the frontal or sagittal planes (spondylolisthesis, laterolisthesis, scoliosis) indication itself. It is In elderly patients who therefore the surgeon’s ■■ severe pre-operative lumbalgia that responds to use of a brace present intercurrent responsibility to assess diseases, the decision the advantages and A few of the disadvantages of arthrodesis are presented below: of adding morbidity disadvantages of adding by performing ■■ longer surgery time arthrodesis to the arthrodesis can be as decompression. ■■ higher exposure and bleeding decisive as the surgical ■■ longer hospital stay indication itself. It is ■■ delay in walking therefore the surgeon’s responsibility to assess ■■ greater post-operative pain the advantages and disadvantages of adding arthrodesis to the decompression.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 21 CLINICAL CASE 6 Patient with neurogenic claudication when walking. Difficulty with prolonged standing.

Solid graft is observed between L4 and L5. Frontal and lateral post-operative X-ray (three years)

Total block of the contrast medium is observed at L4- L5 level upon extension.

Sacral radiculography of the lumbosacral region

Surgery is decided for demcompressive of L4-L5 and posterolateral arthrodesis of L4-L5 without instrumentation.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 22 Decompression, Arthrodesis, and Instrumentation CLINICAL CASE Seventy year old female patient, with neurogenic claudication, very limited Instrumentation to obtain arthrodesis is a well-established practice walking endurance, significant lumbar pain, and degenerative scoliosis in the frontal plane. The advantage of implants are related to the immediate 6 stabilization afford across the treated segments. This would aid in the rate of arthrodesis and provide the patient with further comfort and less pain during the immediate post-operative period.

Several authors have confirmed in prospective studies that instrumentation significantly improves the rate of arthrodesis; however, in the absence of instability, this is not reflected by better clinical results. The advantages should then outweigh the following problems: Lumbar scoliosis of 20° is evidenced. ■■ increased rate of infection Radiographc ■■ high cost of implants ■■ risk for neurovascular complications

Pedicle screws are currently the most frequently used implants. Given their biomechanical characteristics, pedicle screws are the implants that best adapt to lumbar degenerative pathology: ■■ they help maintenance of lumbar lordosis ■■ they can be used in laminectomized vertebrae ■■ in some cases, they allow shorter arthrodesis Specific indications for ■■ mechanically, they are better than hooks instrumentation include theneed for correcting a deformity, controlling severe instability, and the potential for Listhesis at L4-L5 and stenosis at increasing arthrodesis L2‑L3 and L3-L4 can be seen. rates in cases of biological or mechanical MRI, T2, sagittal section predisposition to pseudoarthrosis (decompression of several levels, patients who smoke, endocrine disorders, etc.). .

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 23 6

Listhesis at L4-L5 and marked compression at L2-L3 can be seen.

Sacral radiculography, lateral, on extension

Post-operative spinal alignment can be observed.

Deompression and arthrodesis with instrumentation from L2 to L5 is preformed. Post-operative spinography: frontal and lateral

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 24 Decompression and Dynamic Fixation

Although this option has been used for years, there is no supporting evidence in the literature for the theorectical advantages over arthrodesis alone including: 6 avoiding adjacent segment disease and to obtain better functional results. Interspinal Spacers

The limitations of dynamic fixation also applies to the interspinous process : they are used very frequently even without evidence based support or specific indication. They produce segmental and therefore increase canal and foramina diameters. This is the effect that is wanted for indirect decompression. In vitro studies show that this is possible; however, in vivo reproducibility, the duration of this change, and the effect of kyphotization on other levels have not been adequately evaluated.

Summary: TREATMENT The treatment goal should be to relieve symptoms and to improve functional capacity. Conservative treatment is the first therapeutic option which should be discussed with all patients without motor compromise. The administration and choice of medication is established based on the main symptoms. Chronicity of the clinical picture limits the use of both systemic steroids and opiate derivatives. is often used for conservative management. Passive forms may be useful during the first phases for managing the symptoms.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 25 REFERENCES

Abumi, K., Panjabi, M. M., Kramer, K. M., Duranceau, J., Oxland, T. Verbiest, H. (1954) and Crisco, J. J. (1990 A radicular syndromefrom developmental narrowing of the lumbar Biomechanical evaluation of lumbar spinal stability after graded vertebral canal. J Bone Joint Surg Br, 36-B(2), 230-237. facetectomies. Spine (Phila Pa 1976), 15(11), 1142-1147. Wiltse, L. L. (1991) Amundsen, T., Weber, H., Lilleas, F., Nordal, H. J., Adelnoor, M. and History of spinal disorders. In Frymoyer J. W. (Ed), Adult spine. New Magnaes, B. (1995) York: Raven Press, 33-35. Lumbar spinal stenosis. Clinical and radiologic features. Spine, 20(10), 1178-1186.

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Rush, J. A., Polatin, P. y Gatchel, R. J. (2000) and chronic . Spine, 25(20), 2566-2571.

Rydevik, B., Cohen, D. y Kostuik, J. P. (1997) Spine epidural steroids for patients with lumbar spinal stenosis. Spine, 22(19), 2313-2317.

Satomi, K., Hirabayashi, K. y Toyama, Y. (1992) A clinical study of degenerative spondilolisthesis. Radiographic analysis and choice of treatment. Spine, 17, 1329-1336.

Lumbar Spinal Stenosis. Author: Dr. Marcelo Gruenberg 26 Advancing spine care worldwide

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