ABSTRACT
BACKGROUND: Early-stage spondylolysis (ESS) is one of the common causes of acute low back pain (LBP) in adolescents. Although accurate diagnosis of ESS is important for providing appropriate treatment, differentiating ESS from other low back disorders is difficult by physical signs alone. OBJECTIVES: To elucidate the most common characteristic, namely, motion-provoking LBP, in patients with ESS. DESIGN: Retrospective comparative cohort study. METHOD: We included and categorized adolescents (n = 112; age, <18 years) with acute LBP (<1 month) into the ESS (n = 71) and nonspecific LBP (NS-LBP) (n = 41) groups based on magnetic resonance imaging (MRI) findings. Patients were evaluated using a visual analog scale (VAS), Oswestry Disability Index (ODI), and degree of pain using a numerical rating scale (NRS) provoked by hyperextension, hyperflexion, right and left rotations, and lateral bending in standing position.; the value were compared between the 2 groups. A cut-off value of significance was obtained using receiver operating characteristic (ROC) analysis. RESULTS: The mean scores for VAS and ODI and NRS of each test were as follows (ESS/NS-LBP): VAS, 6.5/6.0; ODI, 19.7/24.6; hyperextension, 4.1/4.1; hyperflexion, 2.4/3.0; rotation, 2.1/2.2; and lateral bending, 2.9/2.2. The ESS group had a significantly greater number of LBP cases provoked by lateral bending than the NS-LBP group. A cut-off lateral bending of 3.5 yielded a diagnosis of ESS. CONCLUSIONS: Our results indicate that lateral bending is the greatest motion-provoking characteristic of LBP in patients with ESS.