Intra-articular injection of botulinum toxin type A for shoulder pain in glenohumeral osteoarthritis: a case series summary and review of the literature

Introduction: Shoulder pain is one of the most common musculoskeletal diseases, and can be due to glenohumeral osteoarthritis, rotator cuff tear, impingement, tendinitis, adhesive capsulitis, and subacromial bursitis. Several therapies have been proposed, including steroids, nonsteroidal anti-inflammatory drugs, intra-articular injections, and physical therapies. Many published studies have reported on the employment of botulinum toxin type A (BoNT-A) to reduce pain in subjects with neurological and musculoskeletal diseases by inhibiting substance P release and other inflammatory factors. Methods: In the present article, we briefly update current knowledge regarding intra-articular BoNT therapy, reviewing existing literature on intra-articular use of BoNT-A, including nonrandomized and randomized prospective and retrospective cohort studies and case series published from December 1989 to November 2017. We also describe a case series of six subjects treated with intraarticular injection of incobotulinumtoxin A for the treatment of pain deriving from osteoarthritis. Conclusion: Intra-articular BoNT-A is effective and minimally invasive. Pain reduction with an increase in shoulder articular range of motion in our experience confirms the effectiveness of BoNT-A injection for the management of this syndrome.