Spondylolisthesis



Spondylolisthesis


Jeffrey S. Ross, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Pediatric Pseudosubluxation


  • Dysplastic


  • Degenerative Disc Disease


  • Spondylolysis


  • Post-Treatment Instability


  • Posterior Column Injury, Cervical


Less Common



  • Osteomyelitis, Pyogenic


  • Tuberculous Infection


  • Tumor



    • Metastasis


    • Lymphoma


    • Multiple Myeloma


    • Primary Bone Tumor



      • Osteosarcoma


      • Osteoblastoma


      • Chondrosarcoma


  • Rheumatoid Arthritis, Adult


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Spondylolisthesis ⇒ displacement of one vertebral body relative to another



    • Dysplastic (congenital abnormality of arch)


    • Isthmic (fatigue or stress fractures of pars)


    • Degenerative (osteoarthritic segmental instability of facets)


    • Traumatic


    • Pathologic (local bone disease)


  • Most common is isthmic and degenerative


  • Spondylolisthesis can occur with or without spondylolysis


  • Spondylolisthesis graded by amount of anterior displacement of superior body by 25% stages



    • < 25% ⇒ grade 1, < 50 ⇒ grade 2, < 75% grade 3, < 100% ⇒ grade 4, > 100% ⇒ spondyloptosis


  • Anterior displacement of vertebral body ⇒ “uncovering” of the posterior disc margin with pseudobulge deformity


  • Look for focal herniations in addition to the pseudobulge at the level of spondylolisthesis and at adjacent levels where stress is increased


  • Spondylolysis ⇒ break in pars interarticularis of vertebrae leaving two parts



    • Anterior component of vertebral body, pedicle, superior facet


    • Posterior component of inferior facet, lamina, spinous process


Helpful Clues for Common Diagnoses



  • Pediatric Pseudosubluxation



    • Normal mobility C2 on C3 in flexion


    • Seen in 40% of children at C2-3, 14% of children at C3-4 level


    • Only seen with flexion


    • May be mistaken for ligamentous injury, since 70% of cervical spine fractures in children occur from C1 to C3


    • C2 displaced up to 3-4 mm


    • Age < 14 years


    • Swischuk line: Drawn from anterior aspect of C1-C3 spinous processes ⇒ normal within 1 mm of anterior C2 spinous process


    • If in doubt on plain film or CT, then MR to exclude ligamentous injury


  • Degenerative Disc Disease



    • Most common at L4-5


    • Wide canal sign not present since no defects in pars


    • Usually grade 1 without lysis


    • Look for severely degenerated facets + disc degeneration


    • Lose of height of neural foramen with stenosis as superior body slips forward


    • Posterior retrolisthesis ⇒ disc degeneration with disc height loss, rostrocaudal subluxation of facets


  • Spondylolysis



    • 90% at L5-S1, bulk of remainder at L4-5



      • L3 and above unusual ⇒ question gymnastics


    • 20% may have unilateral defect in pars


    • May show contralateral compensatory bone hypertrophy and sclerosis



      • Not to be mistaken for osteoid osteoma!


    • Wide canal sign present (increase in AP diameter of bony canal at lysis level relative to normal levels) with bilateral lysis


  • Post-Treatment Instability



    • Deformity that increases with motion and increases over time


    • Dynamic slip > 3 mm in flexion/extension



    • Static slip of 4.5 mm or greater


    • Angulation > 10-15° suggests need for surgical intervention


    • Stabilizing anatomic structures



      • Anterior longitudinal ligament (resists hyperextension)


      • Posterior longitudinal ligament


      • Intertransverse ligaments (connect neighboring transverse processes)


      • Interspinous ligaments (resists hyperflexion)


      • Facet capsule


      • Ligamentum flavum


      • Intervertebral disc: Main stabilizer of lumbar and thoracic spine


      • Muscular attachments


  • Posterior Column Injury, Cervical



    • Fractures of laminae, facets, or spinous processes


    • Disruption of ligaments bridging spinous processes + laminae


    • If capsular ligaments torn, facets, &/or laminae both fractured, rotational instability may exist


    • Flexion extension films or fluoroscopy to assess degree of instability


Helpful Clues for Less Common Diagnoses

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Spondylolisthesis

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