The Prevalence of Spondylolysis and the Diagnostic Sensitivity of Radiography in Adolescent Low Back Pain

ABSTRACT Introduction The aims of this retrospective chart review were to determine the prevalence of radiographically positive spondylolysis based on the historical “gold standard” of single photon emission computed tomography (SPECT) and to evaluate the sensitivity of radiographs in detecting spondylolysis relative to SPECT scans in adolescent athletes presenting with low back pain (LBP). Our secondary outcome measure included an assessment of the variable prevalence of spondylolysis in different athletic subpopulations. Methods Radiographs and SPECT scans for patients with LBP were reviewed for the presence of spondylolysis. The sensitivity and specificity of two-view and four-view radiographs compared to SPECT scans were calculated, and the associations between diagnosis of spondylolysis and age, gender, and sport were determined. Results Nine hundred ninety-nine adolescent patients presented with LBP; 405 SPECT scans were performed. Of those, 141 (35%) SPECT scans were positive for spondylolysis. The prevalence rate for spondylolysis in this population who presented with LBP was 14%. Compared to SPECT scans, two-view radiographs were more specific (92.93%) and had a higher negative likelihood ratio (0.81) for spondylolysis than four-view radiographs. Boys were more likely to have a positive SPECT scan compared to girls (adjusted odds ratio, 6.07; 95% confidence interval, 3.00–12.26). Younger age was significantly associated with a spondylolysis diagnosis (adjusted odds ratio, 1.24; 95% confidence interval, 1.09–1.41). Lacrosse, soccer, softball, and volleyball athletes had a significantly lower risk of spondylolysis diagnosis compared to football and gymnastics athletes. Conclusions This research contributes to data regarding the prevalence of spondylolysis in symptomatic, adolescent athletes. Two-view radiographs were more useful screening tests for spondylolysis than four-view radiographs. Younger athletes, boys, and those who participate in certain sports were more likely to have evidence of spondylolysis on SPECT scans.