Spondylolysis/spondylolisthesis is a topic covered in the 5-Minute Emergency Consult.

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  • Spondylolysis:
    • Bony defect at the pars interarticularis (the isthmus of bone between the superior and inferior facets)
    • Can be unilateral or bilateral
    • Bilateral form has a much higher likelihood of slippage or spondylolisthesis than the unilateral form.
  • Spondylolisthesis:
    • The slipping forward of 1 vertebra upon another
    • Spondylolysis can contribute to spondylolisthesis, which is noted in ∼5% of the population. It is 2–4 times more common in males.
    • Of those with spondylolysis, 50% will have some degree of spondylolisthesis develop during their lifetime, and 50% of those will be symptomatic:
    • Literature does not associate athletic activity with increased slippage.
    • Spondylolisthesis predisposes to nerve root impingement and frequently sciatica.
  • Classification:
    • Type 1—dysplastic: Congenital defect of the neural arch or intra-articular facets is often associated with spina bifida occulta
    • Type 2—isthmic: Stress fracture from repetitive microtrauma through the neural arch
    • Type 3—degenerative: Long-standing segmental instability
    • Type 4—traumatic
    • Type 5—pathologic: Generalized or focal bone disease
    • Spondylolisthesis is divided into 4 grades based on degree of slippage (Meyerding grading system):
      • Grade I: Up to 25% of the vertebral body width
      • Grade II: 26–50% of vertebral body width
      • Grade III: 51–75% of vertebral body width
      • Grade IV: 76–100% of vertebral body width
    • The most common location for spondylolisthesis is L5 displaced on the sacrum (85–95%), followed by L4 on L5.

Pediatric Considerations
  • Spondylolysis is one of the most common causes of serious low back pain in children, although it is most often asymptomatic.
  • Symptoms most often present during adolescent growth spurt from age 10–15 yr.
  • Seen commonly in athletic teens; particularly in sports involving back hyperextension (e.g., gymnastics, diving, football).
  • Acute symptoms are related to trauma.


Unknown; theories include congenital pars anomalies, alterations in bone density, and recurrent subclinical stress injury.

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