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Key Features

Essentials of Diagnosis

  • Injury to the pars interarticularis

  • Usually presents as lower back pain with extension

General Considerations

  • Injury to the pars interarticularis of the vertebral complex results in a stress reaction or an acquired stress fracture

  • In adolescent athletes, however, the incidence of spondylolysis in those presenting with lower back pain is close to 50%

  • Incidence of pars defects in athletes such as gymnasts, dancers, divers, and wrestlers is significantly increased because of the repetitive flexion/extension motions combined with rotation

  • Repetitive overload results in stress fractures

  • Spondylolysis occurs at L5 in 85% of cases

Clinical Findings

  • Midline low back pain that is aggravated by extension, such as arching the back in gymnastics

  • Tight hamstrings are another common physical finding

  • There may be palpable tenderness over the lower lumbar vertebrae, with pain on the single leg hyperextension test (Stork test)


  • Anteroposterior and lateral radiographs of the lumbar spine

  • Oblique radiographic views of the lumbar spine

    • Helpful to look for the so-called Scottie dog sign

    • However, they do not significantly improve diagnostic accuracy and increase radiation exposure

  • Single photon emission computed tomography (SPECT) scan, CT scan, and MRI can be useful to determine the presence of an active spondylotic lesion

    • Bone/SPECT scan shows stress reaction or pars injury before other radiographic changes

    • CT provides excellent definition of bony anatomy and can document healing

    • MRI is an alternative to detect pars interarticularis problems; high-resolution MRI images can now show subtle bone marrow edema of early stress injuries


  • No gold standard

  • Management includes

    • Refraining from hyperextension and high-impact sporting activities

    • Stretching the hamstrings

    • Performing core and back stabilization exercises

  • Athletes can cross-train with low-impact activity and neutral or flexion-based physical therapy

  • Bracing is controversial

  • Surgery is reserved for refractory cases that fail conservative measures



  • Typically, return to play is often delayed 8–12 weeks or longer based on clinical signs of healing

  • Most symptomatic spondylolysis improves with rest and activity modifications (with or without radiologic evidence of healing)

  • Once asymptomatic, an athlete can usually return to sports without restrictions


Kim  H, Green  D: Spondylolysis in the adolescent athlete. Curr Opinion Ped 2011;23:68–72
[PubMed: 21150440] .
Lavelle  W  et al: Pediatric disk herniation. J Am Acad Orthop Surg 2011;19:649–656
[PubMed: 22052641]
Selected issues for the adolescent athlete and the team physician: a consensus statement. Med Sci Sports Exerc Nov 2008;40(11):1997–2012
[PubMed: 19430330]

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