Pulsed and cooled radiofrequency for chronic shoulder pain: a systematic review of comparative and cohort studies.

BACKGROUND: Chronic shoulder pain is a common cause of pain and disability, and repeated corticosteroid injections often provide only temporary symptom relief. Pulsed radiofrequency (PRF) and cooled radiofrequency ablation (CRFA) have emerged as minimally invasive interventional options; however, their comparative effectiveness and the certainty of the supporting evidence remain uncertain. METHODS: This systematic review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, and Web of Science were systematically searched and supplemented by backward citation screening. Randomized and observational clinical studies evaluating PRF or CRFA for chronic shoulder pain were included. Owing to substantial clinical and methodological heterogeneity, the findings were synthesized narratively. Methodological quality and risk of bias were assessed using the Cochrane Risk of Bias 2 (RoB 2) tool, the Risk Of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool, and the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Case Series. The certainty of evidence was evaluated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. RESULTS: In total, 10 studies involving 476 participants met the eligibility criteria, including five randomized controlled trials, one retrospective comparative study, and four uncontrolled CRFA cohort studies. A total of four randomized trials (n = 150) comparing PRF with corticosteroid-based injections or active nerve block interventions consistently demonstrated improvements in pain intensity and shoulder function following PRF. However, PRF did not demonstrate superiority over corticosteroid-based interventions, which generally provided greater short-term pain relief. Furthermore, two studies (n = 220) evaluating adjunctive PRF reported more favorable clinical outcomes when PRF was combined with corticosteroid-based treatment than when corticosteroid-based treatment was administered alone. In addition, four uncontrolled CRFA cohort studies (n = 106) consistently reported improvements in pain intensity and shoulder function over 6-12 months of follow-up; however, no randomized or controlled comparative studies evaluating CRFA were identified. The certainty of evidence was rated as low for comparative and adjunctive PRF studies and as very low for CRFA studies. CONCLUSION: PRF consistently improved pain intensity and shoulder function but did not demonstrate superiority over corticosteroid-based interventions in randomized comparative studies. Preliminary evidence suggests that adjunctive PRF may enhance clinical benefit when combined with corticosteroid-based treatment, whereas evidence supporting CRFA is currently limited to uncontrolled observational studies. Current evidence does not establish a preferred radiofrequency strategy for chronic shoulder pain. Adequately powered, multicenter randomized controlled trials directly comparing PRF, CRFA, and corticosteroid-based interventions are required before definitive treatment recommendations can be made. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/view/CRD42026129, identifier CRD420261295837.