Abstract
PURPOSE: Failed back surgery syndrome (FBSS) is a common and challenging complication after lumbar spine surgery, with around 30% of patients experiencing this condition post-surgery. Spinal cord stimulation (SCS) is a prevalent treatment for FBSS, yet there is a lack of systematic comparisons among different SCS frequencies. This first network meta-analysis (NMA) compared the effectiveness and superiority of different SCS frequencies for FBSS. MATERIAL AND METHODS: Adhering to PRISMA guidelines, we searched PubMed, Web of Science, Embase, and CENTRAL for RCTs. Bayesian random-effects network meta-analysis assessed outcomes including pain reduction, functional capacity, and health-related quality of life. RESULTS: This NMA (11 RCTs; n=2275) revealed efficacy variations among SCS modalities. Based on surface under the cumulative ranking (SUCRA) rankings, subperception SCS (500-1200 Hz) had the highest probability for global pain relief (SUCRA=64.0%) and ≥50% pain reduction (SUCRA=75.3%; P < 0.05 vs low-frequency SCS). High-frequency SCS (10 kHz) was associated with higher SUCRA values for back pain (99.7%; P < 0.05 vs comparators; consistency χ²=1.41, P = 0.703) and leg pain (93.2%; P < 0.05 vs low-frequency SCS), suggesting a potential advantage. For functional outcomes, high-frequency SCS correlated with better ODI scores (SUCRA=85.0%), while subperception SCS showed higher probability for improved EQ-5D metrics (SUCRA=80.3%). All networks satisfied transitivity assumptions without significant inconsistency (P > 0.05). CONCLUSION: This NMA suggests potential differential therapeutic profiles among SCS modalities for FBSS. HF-SCS (10 kHz) showed relatively higher SUCRA values for back pain (99.7%), leg pain (93.2%), and disability improvement (ODI 85.0%). Subperception SCS (500-1200 Hz) was associated with better probability for global pain relief (64.0%), ≥50% pain reduction (75.3%), and HRQoL outcomes (EQ-5D 80.3%). These findings warrant validation in head-to-head RCTs.