Evidence of Multifidus Changes Post-Lumbar Radiofrequency Ablation: A Narrative Literature Review

Background/Objectives: Chronic low back pain (CLBP) is a leading cause of disability worldwide, with lumbar medial branch radiofrequency ablation (LRFA) widely used to manage facet-mediated pain; however, emerging evidence raises concerns regarding its potential to denervate the multifidus muscle—an essential stabilizer of the lumbar spine—thereby exacerbating dysfunction. This narrative review synthesizes current evidence on multifidus atrophy and dysfunction following LRFA, emphasizes its clinical significance, and highlights gaps that warrant further research and therapeutic development. Methods: A comprehensive literature search was conducted using SANRA criteria across the Cochrane Library, Web of Science Core Collection, Scopus, PubMed, and MEDLINE. Studies assessing multifidus morphology or function after LRFA were identified and analyzed. Data were extracted from studies meeting predefined inclusion criteria. The narrative synthesis included a thematic analysis and interpretive integration focusing on clinical practice. Results: Six eligible studies were identified, five cohort studies and one case series. Of these, two confirmed decreased multifidus function post-LRFA. Four studies analyzed post-LRFA structural changes, two of which reported reduced cross-sectional area/fatty infiltration, one no measurable difference, and another an apparent enlargement. The findings are constrained by substantial differences in study design, patient populations, and outcome measures, which limit the ability to establish consistent conclusions. Conclusions: Current evidence suggests that LRFA may lead to structural and functional changes in the multifidus muscle, although findings remain inconsistent due to significant study heterogeneity. Further high-quality, prospective research with standardized imaging and functional assessments is needed to clarify the long-term clinical impact.