Patient selection for lumbar medial branch radiofrequency neurotomy (LMBRFN) remains a topic of debate. Different block paradigms may influence LMBRFN outcomes. This study examined the relationships between block paradigms and treatment results following LMBRFN. A retrospective cohort study of consecutive patients undergoing first-time LMBRFN between 2016 and 2022 at two associated Canadian clinics was performed. Patients were grouped into six prognostic block paradigms based on block type (medial branch block MBB vs. intra-articular block IAB), number of blocks (single vs. dual), and percent pain relief (50–79% vs. ≥80%): 1 = MBB/MBB ≥80%, 2 = MBB/MBB 50–79%, 3 = IAB/MBB ≥80%, 4 = IAB/MBB 50–79%, 5 = MBB ≥80%, and 6 = MBB 50–79%. Treatment success was defined by (1) ≥50% reduction in numerical rating scale (NRS) pain score and (2) the minimal clinically important difference (MCID) in Pain Disability Quality-of-Life Questionnaire–Spine (PDQQ-S) at 3 months post-procedure. Logistic regression was used to assess associations between block paradigm and outcomes while controlling for select demographic and clinical factors. Among 631 included patients (57.1% female; mean age 62.3 ± 12.9 years), 46.9% achieved ≥50% NRS reduction and 47.7% met the MCID for PDQQ-S at 3 months. No significant associations were found between block paradigms and ≥50% pain relief. However, the IAB/MBB 50–79% paradigm was associated with significantly lower odds of functional improvement by the PDQQ-S (OR = 0.31; p = 0.02). Patients who were working at the time of the procedure had higher odds of treatment success with respect to pain (OR = 2.51; p < 0.01) and function (OR = 2.21; p < 0.01). In this cohort, nearly half of patients experienced clinically meaningful pain reduction at 3 months post-LMBRFN, regardless of block selection criteria, challenging the need for restrictive paradigms. However, patients selected by IAB/MBB with 50–79% pain relief were less likely to experience clinically significant improvements to function. Active employment was linked to better 3-month outcomes for both pain and function, highlighting potential psychosocial factors. Larger prospective studies with long-term follow-up are needed to confirm these findings and optimize patient selection for LMBRFN.
Joshi et al. (Wed,) studied this question.