Journal of Spine

Background: Adolescent lumbar spondylolysis is considered to be a fatigue fracture caused by repeated mechanical stress and sports activities are often thought to be the cause. The incidence of lumbar spondylolysis has been reported to be generally 3%-6%, and 4%-10% among patients complaining LBP. In athletes, the incidence of lumbar spondylolysis during adolescence has ranged from approximately 15% to 50%. The purpose of this study was to prospectively investigate to determine the imaging and pain characteristics of spondylolysis on lumbar extension among adolescent patients with Low Back Pain (LBP) who played sports.

Methods: 100 patients (a mean age of 14.8 years) were selected as the subjects and were investigated sports activities, duration of LBP, and pain with lumbar repetitive extension. Plain X-ray, CT, and high-intensity signal changes in the pedicle on T2 MRI were examined for diagnostic indications of lumbar spondylolysis.

Results: Spondylolysis was confirmed by plain X-ray in 34 patients, 8 were confirmed on CT. Spondylolysis was eventually identified in 42 of the 100 patients (42.0%). High-intensity signal changes in the pedicle on T2 MRI were recognized in 29 cases. Pain with lumbar extension occurred in 69 of the 100 patients (69.0%) including 34 of the 42 patients with spondylolysis (81.0%) and 35 of the 58 patients without spondylolysis (60.3%). Therefore, the sensitivity of the lumbar extension was 81.0% (34/42), and its specificity was 39.7% (23/58).

Conclusion: Among adolescent athletes, the incidence of lumbar spondylolysis was 42.0%, and of the 69 patients with pain with lumbar extension, 34 (81.0%) were confirmed to have spondylolysis. Pain with lumbar extension appears to be a good screening indicator for adolescent lumbar spondylolysis.