Conservative Treatment and Unfavorable Factors to Bone Healing of “Pre-lysis”-Stage Lumbar Spondylolysis in Adolescents

STUDY DESIGN: Retrospective cohort study. PURPOSE: To evaluate the clinical outcomes of the conservative treatment of “pre-lysis”-stage lumbar spondylolysis. OVERVIEW OF LITERATURE: With the widespread use of magnetic resonance imaging (MRI) for early diagnosis of lumbar spondylolysis, a new disease stage called pre-lysis has emerged, in which intensity change is observed only on MRI without a fracture line on computed tomography. This study aimed to evaluate the clinical outcomes and factors unfavorable to bone healing of the conservative treatment of pre-lysis-stage lumbar spondylolysis. METHODS: Fifty-three patients with 57 fresh pre-lysis-stage lesions who had completed conservative treatment were included in the study (40 men, 13 women; mean age, 14.3 years). We investigated the rate of bone healing and the relationship between bone healing after conservative therapy and factors such as age, sex, vertebral level, unilateral/bilateral lesions, and presence of spina bifida occulta. RESULTS: The overall bone healing rate was 95% (54/57 lesions). Bilateral lesions had a significantly lower bone healing rate than unilateral lesions (86% vs. 100%, p=0.046). There were no statistically significant differences based on age, sex, vertebral level, or presence of spina bifida occulta. CONCLUSIONS: The bone healing rate in unilateral lesions was 100%, which was significantly higher than that in bilateral lesions. It is important to detect and initiate treatment while the lesion is still unilateral, if possible.