The imaging features of spondylolisthesis : what the clinician needs to know

Transcription

1 The imaging features of spondylolisthesis : what the clinician needs to know Poster No.: C-1018 Congress: ECR 2011 Type: Authors: Educational Exhibit D. Shah 1, C. J. Burke 1, A. C. andi 2, R. Houghton 1 ; 1 London/UK, 2 london/uk Keywords: DOI: Musculoskeletal system, Musculoskeletal spine /ecr2011/C-1018 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 28

2 Learning objectives - to recognise there are 6 different types of spondylolisthesis - to compare the imaging features of these - to recall different methods for measuring the severity of spondylolisthesis - to appreciate the differences in management between the different types - to know which types need prompt review and correction Background There is a relatively poor understanding of lumbar spondylolisthesis amongst radiologists and other clinicians, with a commonly held misconception that all cases are due to pars defects. In reality, spondylolisthesis has multiple causes with differing clinical implications. A basic knowledge of this is essential for all reporting radiologists due to the ready availability of multiplanar imaging, necessitating thorough spinal review even on nonmusculoskeletal examinations. Definition: Spondylolisthesis= The displacement of one vertebra on another Greek: (spondylos - vertebra) (olisthesis - slippage) Page 2 of 28

3 Classification Spondylolisthesis can be classified into six different categories based on aetiology. Knowledge of the underlying pathology enables the radiologist to offer a comprehensive and useful report for the clinician. 1. Dysplastic (congenital) 2. Isthmic(spondylolyis/pars defects) 3. Degenerative 4. Traumatic 5. Pathologic 6. Iatrogenic (post-surgical) Imaging findings OR Procedure details 1.Dysplastic Congenital dysplasia of L5/S1 facet joint - Horizontal malorientation of superior articular facet on inferior facet (type A) or sagittal malorientation (type B) results in slip -Neural arch intact, therefore high incidence of neural compromise (25-35%) Management 4-6 monthly plain X-rays until skeletal maturity If stable - conservative If progression of slip or symptomatic, decompression and arthrodesis of involved motion segment 2. Isthmic Dysplasia of pars interarticularis in conjunction with repetitive microfractures Page 3 of 28

4 -Constant axial downward force caused by upright posture (not found in quadripeds) produces stress fracture through an abnormal pars - By definition, bilateral pars defects are required to produce a slip -Occurs before skeletal maturity -Strong genetic component -Abnormal pars (fibrous bands) have abundant nerve endings therefore often painful Management -Grade 1: conservative (periodic observation) -Grade 2: conservative, restriction of activity, bracing -Grade 3 and 4 : consider surgery to correct deformity, prevent slip progression, symptomatic relief Eg Pars defect repair, (laminectomy), posterolateral fusion +/- decompression 3. Degenerative -Common over the age of 40 -Occurs mostly at L4/5 level -Intact pars interarticularis -Associated with degenerative disk disease, facet joint hypertrophy and arthritis -Sagittal malorientation of facet joints as a result of degenerative changes -5-6x more common in women -Low back pain radiating to buttocks is common -Slip rarely greater than grade 1-50% have radicular symptoms related to L5 root -Important differential of intermittent claudication Page 4 of 28

5 Management -Exclude cauda equina syndrome (rare) -Conservative : bedrest, NSAIDS, exercise/physiotherapy -Interventional : facet joint injections, epidural steroids -Surgical : for persistent or recurrent pain/ spinal stenosis with progressive neurological deficit ie. fusion or posterolateral decompression and fusion +/- reduction 4. Traumatic -Spondylolisthesis secondary to pure trauma is extremely rare - Large forces required to cause traumatic fracture/dislocation at facet joint or lamina - even in the setting of trauma, far more likely to have incidental spondylolyisis than traumatic spondylolisthesis - if present, associated with other spinal injuries therefore comprehensive whole spine imaging necessary - management as for isthmic 5. Pathologic - Secondary to bony disease eg osteoporosis, osteomalacia, (where microfactures and remodelling result in segmental instability) Paget's disease, osteogenesis imperfecta (due to elongation of the pedicle) - Commonly due to infection eg TB/pyogenic spondylodiscitis (severe destruction of bony architecture) -Primary/secondary neoplasm -Management is of underlying disease process and complications 6. Iatrogenic -Due to surgical disruption of bone/ligaments/intervertebral disc Page 5 of 28

6 -Previously common due to higher use of posterior decompression without fusion of involved segment eg in treatment of symptomatic disc disease -Discectomy also associated with some instability -Now posterior decompression increasingly performed with fusion so rarely occurs Management -Instrumented posterolateral fusion +/- interbody fusion depending on the degree of instability (but stability at expense of lack of movement) -Risk of kyphosis at superior extent of instrumentation which often necessitates further fusion Images for this section: Page 6 of 28

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8 Fig. 1: GRADE 1 ISTHMIC SPONDYLOLISTHESIS - note associated lumbarised S1 vertebra (common association) Page 8 of 28

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10 Fig. 2: PATHOLOGIC RETROLISTHESIS at L4/5 secondary to pyogenic spondylodiscitis Page 10 of 28

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12 Fig. 3: grade 2 (25-50% SLIP) DEGENERATIVE SPONDYLOLISTHESIS at L3/4 with spinal canal stenosis Fig. 4: Axial MRI of L3/4 DEGENERATIVE SPONDYLOLISTHESIS showing sagittal malorientation of facet joints ( Page 12 of 28

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14 Fig. 5: TRAUMATIC SPONDYLOLISTHESIS in polytrauma: multi-level posterior element fracture-dislocations (extremely rare) Page 14 of 28

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16 Fig. 6: TRAUMATIC SPONDYLOLISTHESIS in polytrauma: multi-level posterior element fracture-dislocations (extremely rare) Page 16 of 28

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18 Fig. 7: IATROGENIC RETROLISTHESIS AT L2/3 - secondary to previous decompression without fusion Page 18 of 28

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20 Fig. 8: IATROGENIC RETROLISTHESIS -secondary to previous decompression without fusion Page 20 of 28

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22 Fig. 9: Grade 1 (0-25%) ISTHMIC SPONDYLOLISTHESIS of L5/S1 Page 22 of 28

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24 Fig. 10: DYSPLASTIC SPONDYLOLISTHESIS - note horizontal orientation of facet joint Page 24 of 28

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26 Fig. 11: Grade V ISTHMIC SPONDYLOLISTHESIS secondary to pars defects - Grade V (>100% slip) is also termed spondyloptosis Page 26 of 28

27 Conclusion There are 6 types of spondylolisthesis: DYSPLASTIC ISTHMIC DEGENERATIVE PATHOLOGIC TRAUMATIC IATROGENIC The most common are ISTHMIC DEGENERATIVE DYSPLASTIC Dysplastic/degenerative have a higher incidence of neural compromise. Undiagnosed dyplastic and high-grade isthmic spondylolisthesis needs referral and follow up until skeletal maturity. Dynamic flexion/extension views or axial-loaded MRI required before a slip can be considered 'stable'. Personal Information References 1) Wiltse L, Winter RB. Terminology and measurement of spondylolisthesis. J Bone Joint Surg Am Jul; 65(6): ) Butt S, Saifuddin A. The imaging of lumbar spondylolisthesis. Clin Radiol May; 60(5): ) Boxall D, Bradford DS, Winter RB, Moe JH. Management of severe spondylolisthesis in children and adults. J Bone Joint Surg 1979;61(4): Page 27 of 28

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