Efficacy and outcome predictors of fluoroscopy-guided facet joint injection for spondylolysis

Objective: To assess the efficacy of fluoroscopy-guided facet joint injection for symptomatic spondylolysis and to analyze the outcome predictors. Materials and methods: This study included 108 patients who underwent fluoroscopy-guided facet joint steroid injection for symptomatic spondylolysis with follow-up medical records from January 2013 to December 2016. Among them, 47 patients underwent concomitant epidural steroid injection. Response to injection was assessed at the initial follow-up. The symptom-free interval was analyzed using the Kaplan–Meier method. Outcome predictors were statistically analyzed using independent t test and Chi-square test. Results: The facet joint injection was effective in 52 of 108 (48.1%) patients at initial follow-up. Recurrence was reported in 21 of these 52 (40.4%) patients. For the 52 patients in whom facet joint injection was effective, the median symptom-free interval was 298 days (95% confidence interval, 29–567 days). No significant difference was found in the response between the group with facet joint injection only (n = 61) and the group with facet joint injection and additional ESI (n = 47). Additionally, no significant outcome predictors were detected. Conclusions: Fluoroscopy-guided facet joint injection may potentially be an effective therapy for providing prolonged pain relief and avoiding unnecessary surgery for symptomatic spondylolysis without significant outcome predictors.