Utility of Physical Examination Findings for Predicting Low-Back Pain in Adolescent Patients with Early-Stage Spondylolysis: A Retrospective Comparative Cohort Study

INTRODUCTION: This study aimed to elucidate low-back pain (LBP) characteristics, i.e., its qualities, extent, and location, in patients with early-stage spondylolysis (ESS). METHODS: We recruited patients (≤18 years old) who presented with acute LBP lasting up to 1 month. Patients were divided into ESS and nonspecific LBP (NS-LBP) groups based on their magnetic resonance imaging findings; patients showing no pathological findings that might explain the cause of LBP were classified as NS-LBP. All patients were evaluated using the following tests: hyperextension and hyperflexion (pain provocation tests in a standing position), pain quality (sharp/dull), pain extent (fingertip-sized area/palm-sized area), and pain location (left and/or right pain in side [side]/central pain [center]). We have also compared outcomes between the ESS and NS-LBP groups in terms of gender and physical symptoms. RESULTS: Of 101 patients, 53 were determined to have ESS (ESS group: mean age: 14.3 years old; 43 males/10 females), whereas 48 had no pathological findings explaining the LBP origin [NS-LBP group (mean age, 14.4 years old; 31 males/17 females)]. Chi-squared test has identified gender (male), a negative result on hyperflexion test, pain extent (fingertip-sized area), and pain location (side) to be significantly associated with ESS. Among these, regression analysis revealed that male gender and LBP located on the side were significantly associated with ESS (p<0.05). CONCLUSIONS: Although the hyperextension test is generally considered useful for ESS, we demonstrated that its association is not deemed significant. Our results indicate that male gender, a negative result of the hyperflexion test, fingertip-sized pain area, and LBP on the side may be specific characteristics of ESS. Of these physical signs, male gender and LBP located on the side are characteristic factors suggesting ESS presence.