Spondylolysis

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)

Diagnosis

• 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

Treatment

• 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

Outcome

Prognosis

• 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

References