36-Month prospective multicenter randomized controlled trial comparing endoscopic facet denervation and cryoneurolysis for chronic lumbar facet joint pain.

BACKGROUND: Cryoneurolysis and endoscopic facet denervation are established minimally invasive treatment options for lumbar facet joint-mediated pain; however, comparative evidence regarding their long-term effectiveness remains limited. This study compared the 36-month clinical outcomes of both procedures in a prospective multicenter randomized clinical trial. METHODS: Eighty patients with lumbar facet joint-mediated pain confirmed by dual controlled medial branch blocks (≥ 70% pain relief) were randomized to undergo cryoneurolysis (n = 40) or endoscopic facet denervation (n = 40). The primary endpoint was low back pain intensity measured using the Numeric Rating Scale (NRS) at the predefined 36-month follow-up. Secondary outcomes included disability, health-related quality of life, and reintervention rates. Longitudinal mixed-effects modelling and conservative sensitivity analyses were performed. RESULTS: Both treatment groups demonstrated significant and sustained improvements in pain, disability, and health-related quality of life compared with baseline. No statistically significant between-group difference was observed for the primary endpoint at 36 months. Longitudinal mixed-effects modelling demonstrated no significant treatment-by-time interaction (p = 0.74), with an adjusted between-group difference of 0.01 NRS points (95% CI -1.07 to 1.10; p = 0.98). Sensitivity analyses yielded findings consistent with the primary mixed-effects analysis. Reintervention was required in 8 of 40 patients (20.0%) in the cryoneurolysis group and 12 of 40 patients (30.0%) in the endoscopic denervation group (p = 0.44). CONCLUSION: Both cryoneurolysis and endoscopic facet denervation were associated with sustained improvements in pain, disability, and health-related quality of life in carefully selected patients with lumbar facet joint-mediated pain. No statistically significant differences in long-term pain trajectories were observed between treatment groups. Although some secondary analyses numerically favored cryoneurolysis, the study was not designed or powered to establish superiority, equivalence, or non-inferiority between treatment modalities. Larger prospective studies are warranted to confirm these findings.