Abstract
BACKGROUND: Previous study of spinal neurotomy procedures indicates that stringent block selection improves outcomes. However, this pattern is not established for sacral lateral branch radiofrequency neurotomy (SLBRFN). Few SLBRFN studies have used stringent block selection criteria such as ≥80 % pain reduction following dual sacral lateral branch blocks (SLBB). OBJECTIVE: Evaluate the effectiveness of SLBRFN in patients with ≥80 % pain relief following dual SLBBs. METHODS: Retrospective single-arm cohort study of consecutive patients from two Canadian musculoskeletal and pain clinics who underwent first-time SLBRFN after report of ≥80 % pain relief following dual diagnostic SLBBs. Patients were identified by electronic medical record query between 2016 and 2022. The primary outcome was the proportion of individuals with a ≥50 % reduction in the numeric pain rating scale (NPRS) score three months after SLBRFN. Secondary outcomes included the proportion of responders achieving the minimal clinically important difference (MCID) on the pain disability quality-of-life questionnaire (PDQQ), and the duration and mean percentage of pain relief among those with recurrent symptoms after a successful SLBRFN. RESULTS: Of the 70 participants included, 32 (45.7 %; 95 % CI = 34.6-57.3) reported a ≥50 % reduction in NPRS, and 35 (50.0 %; 95 % CI = 38.6-61.4) achieved the MCID on the PDQQ at 3-months. Among the 17 patients who reported a return of symptoms, the mean duration of relief was 8.0 ± 3.5 months, and the mean percentage of pain relief was 77.9 % ± 16.4 %. Logistic regression models revealed that the use of multi-tined RF probes and lower patient BMI were associated with treatment success. DISCUSSION/CONCLUSION: SLBRFN reduced pain and disability in approximately 50 % of patients at 3 months when selected using relatively restrictive selection criteria. Treatment success was associated with multi-tined RF probe type and lower patient BMI. Larger prospective studies assessing long-term outcomes are needed to further evaluate the impact of different selection criteria and techniques on SLBRFN effectiveness.