Evaluating prognostic block selection criteria in cervical medial branch radiofrequency neurotomy: A retrospective cohort study

Abstract

Background

Considerable variability exists in the literature record regarding patient selection criteria for cervical medial branch radiofrequency neurotomy (CMBRFN). Few prior studies have assessed the correlation between different prognostic block paradigms and treatment outcomes for this procedure.

Objectives

Examine the association between various prognostic block selection criteria and CMBRFN success rates.

Methods

Retrospective cohort study of consecutive patients from two Canadian musculoskeletal pain management clinics who underwent first-time CMBRFN between 2016 and 2022 with a three-tined cannula utilizing a perpendicular approach. Patients were categorized according to prognostic block paradigms (single vs. dual), block type (medial branch block [MBB] vs. intraarticular block [IAB]), and percentage pain relief after blocks. Six block criteria were established: 1 = MBB/MBB≥80 %; 2 = MBB/MBB 50–79 %; 3 = IAB/MBB≥80 %; 4 = IAB/MBB 50–79 %; 5 = MBB≥80 %; 6 = MBB 50–79 %. Treatment success was evaluated at 3 months post-CMBRFN as the proportion of participants with (1) ≥50 % NRS pain score reduction (the primary outcome) and (2) ≥17-point score decrease (the minimal clinically important difference [MCID]) on the Pain Disability Quality-of-Life Questionnaire – Spine (PDQQ-S). Logistic regression analyses were used to explore associations between block criteria and CMBRFN treatment success.

Results

A total of 171 consecutive patients (58.5 % female; 58.0 ± 12.1 years of age; BMI 28.7 ± 6.0 kg/m²) were included. 60.8 % (95%CI: 53.3–67.8 %) and 61.4 % (95%CI: 53.9–68.7 %) of patients reported ≥50 % NRS and ≥17-point PDQQ-S reduction, respectively. After controlling for demographic factors, there were no statistically significant differences in the odds of treatment success amongst individuals selected by various prognostic block paradigms.

Conclusion

Over 60 % of patients who underwent CMBRFN reported clinically significant magnitudes of improvement in pain and disability at three months post-CMBRFN, regardless of prognostic block selection criteria. These findings suggest that multiple block strategies might be employed to determine eligibility for CMBRFN. Larger, prospective studies including long-term outcome assessments are needed to further evaluate these findings.