A systematic review and meta-analysis of radiofrequency procedures on innervation to the shoulder joint for relieving chronic pain

Background and Objective: Studies have reported relief of chronic shoulder pain with non-ablative pulsed neuromodulatory (pRF) or ablative radiofrequency (aRF) procedures on innervation of the shoulder joint but interpretation of these reports is hampered by inconsistent indications, anatomic targets and follow-up. This systematic review was conducted to synthesize the existing literature on procedures employing pRF or aRF for treating chronic shoulder pain. Databases and Data Treatment: MEDLINE and other medical literature databases were reviewed up to 31 December 2019 for publications on pRF or aRF procedures on shoulder joint innervation to relieve chronic pain. Data on analgesic and functional outcomes measured at any time point following the interventions were extracted. Existing knowledge on innervation of the shoulder joint with relevance to RF procedures was also synthesized. Results: In all, 42 publications, 7 randomized controlled trials (RCTs) and 35 observational studies, case series or reports were identified. Thirty-six of these publications were on pRF procedure and 29 of these reported procedures exclusively targeting the suprascapular nerve. A meta-analysis of the seven RCTs evaluating pRF indicated no analgesic benefit or functional improvement with this treatment over conventional medical management. Case series and reports on aRF indicate a potential for analgesic benefit but the quality of this evidence was low. Conclusions: RF treatments targeting the sensory innervation of the shoulder joint affected by degenerative conditions have the potential to reduce pain but the current evidence does not suggest analgesic or functional benefit (GRADE certainty of evidence—low). Studies of high methodological quality are required to further investigate the role of these interventions. Significance: This is a comprehensive review of literature on pulsed (non-ablative) and ablative radiofrequency (RF) procedures for chronic shoulder pain. The systematic review and meta-analysis of 7 trials found that pulsed RF for chronic shoulder pain provided similar analgesia and functional improvement as conservative medical management at three months after the procedures. The case series and reports on ablative RF for shoulder pain indicate possible analgesic benefit but their quality was low. This review highlights the need for studies of a high quality on ablative RF treatments for chronic shoulder pain.