2022 Volume 13 Issue 5 Pages 746-751
Introduction: Lumbar spondylolysis is a frequent fatigue fracture in adolescent athletes. The fourth lumbar vertebra (L4) spondylolysis is less frequent than the fifth lumbar vertebra (L5).
Methods: A total of 41 cases with 59 lesions (excluding pseudarthrosis lesions) diagnosed as L4 spondylolysis over 6 years from 2014 were included in this study. Conservative treatment included semi-hard brace and exercise prohibition and athletic rehabilitation were performed in all cases. We investigated age, sex, discipline of sport, unilateral/bilateral cases, and pathological stage of Computed Tomography (CT) axial slice at initial examination. After Magnetic Resonance Imaging (MRI) signal change disappeared, CT was performed to evaluate for bony union or pseudoarthrosis. The relationship between each factor and the bony union was analyzed using Fisher exact tests. Significance was set at p < 0.05.
Results: The mean age of the patients was 14.5 years, 31 were boys and 10 were girls, and the most common discipline was soccer, followed by baseball. There were 21 unilateral cases and 20 bilateral cases. Eighteen of the bilateral cases were bilateral fresh cases and two cases were unilateral fresh with contralateral pseudarthrosis cases. The union rate after conservative treatment was 81%, and the average treatment period was 105 days. The distribution of pathological stage was pre-lysis:early-stage:progressive stage = 15:30:14. The union rate of pre-lysis and early-stage was 89% and the union rate of the progressive stage was 57%. There was a significantly lower union rate in the progressive stage than pre-lysis and early-stage (p = 0.015). Additionally, the union rate of unilateral cases was 95% and that of bilateral cases was 70%. There was a significantly lower union rate in bilateral cases than unilateral cases (p = 0.045). The union rate of bilateral fresh cases was 78% and that of unilateral fresh with contralateral pseudoarthrosis cases was 0%. There was a relatively lower union rate in unilateral fresh with contralateral pseudoarthrosis cases than bilateral fresh cases (p = 0.078).
Conclusions: The union rate in the conservative treatment of L4 spondylolysis is 81%; however, the union rate of progressive stage lesions was significantly lower. Furthermore, the union rate of bilateral cases was significantly lower and that of unilateral fresh with contralateral pseudoarthrosis cases was relatively lower.
