British Medical Books Health Issues Computerized Tomography
  • Articles & Publications
  • Related Sites
  • Second Opinions
  • Medico Legal Reports

Spondylolisthesis

Definition

  • an anterior or posterior slipping or displacement of one vertebra on another
  • a unilateral or bilateral defect of the pars inter-articularis w/out displacement of the vertebra known as spondylolysis or spondyloschisis.
  • from the Greek "spondylo" meaning vertebra and "olisthesis" meaning slip

Incidence

  • ~4% at age of 6 yr
  • 6% in adults
    • 6% of these becomes symptomatic

Classification

  • Wiltse
  • based on the cause of the defect
  • Dysplastic(congenital)
    • congenital abnormalities of the upper sacrum or the arch of L5 cause slipping
    • abN or insufficient facet joint & disc complex
    • rare
    • more common in girls
    • high familial tendency
    • high incidence of neurology even w/ minor slips - intact lamina of L5 pulling on dura
  • Isthmic
    • hereditary dysplasia of the pars + stresses from upright posture → bilateral defect in pars interarticularis
    • most common form
    • 2:1 male - female ratio, more common in whites
    • not present at birth
    • 5% at age 6-8 yr, 7-6% by the age of 18 yr
    • especially important in repetitive hyperextension sports ( fast bowlers, gymnasts )
    • three types can be recognised.
      • Lytic
        • fatigue fracture of the pars interarticularis
        • strong hereditary tendency
      • Elongated pars
        • micro fractures that heal w/ elongated pars
      • Acute fracture of the pars interarticularis
        • from significant trauma
        • most frequently with spondylolysis, slippage is rare
  • Degenerative
    • due to disc & facet joint degeneration & segmental instability
    • 5x more in females, 3x more in black women
    • usually at L4-L5 level
    • transitional vertebra - sacralised L5 common
    • older than 40 yr
  • Traumatic
    • results from fractures in areas of facet
  • Pathologic
    • generalised or localised bone disease present
    • in Albers-Schonberg dx(osteopetrosis), arthrogryposis, Paget's disease & syphilitic bone dx.
    • extremely rare
  • Post surgical(iatrogenic)
    • surgical disruption of ligamentous, discal or bony structures

Symptoms

Pain

    • most common
    • it typically begins with the adolescent growth spurt
    • two types:
      • back ache - dull, aching pain in the back, buttocks & posterior thigh (pars non-union, ligamentous stretch may be source)
      • nerve root irritation usually at L5-S1(sciatica) - radiating pain into the lower extremities
  • Neurologic signs
    • paraesthesias, weakness & incontinence
    • claudication symptoms

Examination

    • gait abnormalities
    • waddle w/ limited hip flexion, shortened stride length & a wide base of support
    • results from hamstring tightness, vertical tilting of the pelvis (lumbosacral kyphosis), compensatory lumbar hyperlordosis & FFD of the hips and knees
    • change in normal posture
    • lumbosacral kyphosis & compensatory lumbar hyperlordosis
    • palpable step-off & trunk shortening with significant slip (Gr III-IV)
    • local tenderness, muscle spasm
    • hamstring tightness → limited trunk flexion, decreased straight leg raising

Associated conditions

    • spina bifida occulta 30-70% with isthmic, 40% with dysplastic ~
    • scoliosis 5-7% in spondylolisthesis - usually corrects with treatment of the slip
    • lumbarisation or sacralisation 7-9%

Radiological studies

X-rays

    • AP & lateral lumbo-sacral views + coned LS junction
    • standing
    • disruption of pars, degree of slippage on lateral
    • reversed Napoleon hat sign on AP (spondyloptosis)
    • oblique views
    • "Scottie dog's neck" observed for unilateral defects

Radiographic measurements

  • Meyerding grading - % slip
    • grade 1 - < 25% anterior slip
    • grade 2 - 25 – 50% slip
    • grade 3 - 50 – 75% slip
    • grade 4 - > 75% slip
    • spondyloptosis = complete slip off
  • slip angle
    • measures lumbosacral kyphosis
    Slip-Angle
  • Bone scan
    • in acute injury positive before pars defect visible on X-ray
    • may benefit from POP immobilisation
  • Myelography
    • rarely shows nerve root lesion or herniated disc
    • block always due to the tenting of the dura over the body at the level of the slip
  • CT or MRI
    • to evaluate nerve root compression
    • associated disc degeneration → fusion level above
  • Treatment
    • treatment in children is different to that in adults

Non-operative treatment

  • Clinical follow up
    • Wiltse's guidelines:
  • Pars defect discovered very early (less than ten years):
    • radiographs every four month initially; later, semiannually to 15 years of age
    • then at one- to two-year intervals until completion of growth.
  • Up to 25 percent isthmic spondylolisthesis in an asymptomatic child:
    • no limitation of activity
    • recommend an occupation avoiding heavy labour
  • Up to 50 percent slip in an asymptomatic child
    • radiographs semiannually until skeletal maturity
    • recommend activity modification and refraining from contact sports
    • advise an occupation avoiding heavy labour
  • Up to 50 percent slip in a symptomatic patient:
    • initiate conservative therapy (exercises, corset, brace, limitation of activities)
    • recommend semiannual radiographs until 15 years of age and annually thereafter until age 17 or 18
    • advise avoiding heavy labour
  • Greater than 50 per cent slip
    • consider surgical treatment

Physiotherapy

    • hamstring stretching, lumbodorsal fascial stretching, and abdominal strengthening

Immobilisation

    • bedrest, corset, brace or plaster jacket
    • in patients with symptoms , but < 50% slippage
    • in acute pars # -s – if bone scan hot

Surgical treatment

Indications

  • Persistence symptoms for at least one year despite adequate conservative rx.
  • Persistently abnormal gait, tight hamstrings
  • Postural deformities eg.sciatic scoliosis
  • Progressive neurologic deficit
  • Progressive slipping (> 25 to 50%) even when asymptomatic
  • Slip angle > 40-50° in a growing child
    • likely to be associated with further progression and deformity

Goals

    • reduction of back & leg pain
    • prevention of further slip
    • stabilisation of the unstable L5-S1 segment
    • reversal of neurologic deficit
    • restoration of more normal spine mechanics, posture and gait
    • improved appearance

Pars defect repair

    • in <25% slip
    • motion is preserved in the segment
    • evaluate disc as it can cause pain (MRI or discogram)

Decompression

    • if radicular pain
    • Gill's laminectomy → residual back pain & increased slippage
      • not recommended without fusion

In situ fusion

    • usually if <50% slip & no neurology
    • posterolateral more effective than posterior
    • post operative immobilisation in brace or jacket for 3/12
    • instrumentation may be used
    • disadvantage:
      • pseudoarthrosis rate higher than in other fusions
      • further slippage
      • neurological risk if > 50% slip
      • residual deformity

Reduction & fixation

    • advantage:
      • stops progression of deformity
      • promotes union
      • limits fusion length
      • restores body posture & mechanics
    • indications:
      • cauda equina sy.
      • progressive slip >50%
      • major deformity with decompensation, distress
    • traction-cast reduction
    • posterior distraction instrumentation
    • anterior interbody fusion

spondylolysis in children

  • no slip & asymptomatic - no treatment
  • no slip but symptomatic - brace for 6 to 8 months
  • painful spondylolysis not responding to bracing - L5-S1 arthrodesis
  • painful spondylolysis not responding to bracing at L4 - repair of lesion
  • Scott technique - wire TP to SP

spondylolysis in adults

  • if slip is < 25% - pars repair

spondylolisthesis in children

    • grade 1 slips
    • fusion if pain despite conservative treatment
    • grade 2 slips
    • if between 6 & 12 years - fusion even if asymptomatic because of risk of progression
    • if mature adolescent & symptomatic - fusion; if asymptomatic observation
    • grade 3 & 4
    • all should be fused because of likelihood to progress
  • usually need L4 to S1 fusion w/ rigid fixation - high rate of pseudo-arthrosis
  • reduction probably not necessary

spondylolisthesis in adults

    • symptomatic grade 1 & 2
    • fusion (posterolateral) in situ + fixation
    • symptomatic grade 3 or 4
    • controversial
    • ? reduce deformity or fusion in situ with fixation

spondylolisthesis with neurology in children

    • nerve root decompression + fusion (ALWAYS)
    • usually L5 nerve root that is compressed (between pars & disc or vertebra below)
    • sometimes the S1(remove part of body of S1)

spondylolisthesis with neurology in adults

    • decompression only (Gills) - will have residual backache
    • probably should also do a fusion with or without internal fixation

severe spondylolisthesis (spondyloptosis) with lumbar sacral kyphosis

    • options: anterior fusion, posterior fusion with or without reduction, combined anterior & posterior fusion, vertebrectomy
    • may or may not be combined with internal fixation
  • treatment of spondylolisthesis is associated with a higher incidence of pseudo-arthrosis than other fusions

© 2012 - 2014 Dr Attila Szabo, Orthopaedic Surgeon. Website designed by Personalised Promotions in association with SA Medical Specialists. .