Botulinum toxin for posterior shoulder instability unresponsive to conventional management.

Abstract

This case report describes the successful use of botulinum toxin A injections to treat persistent shoulder pain and instability in a middle-aged man with posterior labral tear and capsular laxity. Despite arthroscopic repair, the patient experienced recurring pain attributed to hypertonicity of the latissimus dorsi muscle. Botulinum toxin injection into the latissimus pars ascendens resulted in significant pain relief and improved function within 1 month. At 6 months, the patient had resumed normal activities pain-free. This innovative application of botulinum toxin beyond spasticity management effectively addressed residual muscular imbalance driving instability. It represents a novel therapeutic option for refractory shoulder pain and dysfunction. Further research is warranted to establish efficacy and safety, but this positive outcome highlights the potential to expand indications for botulinum toxin in musculoskeletal disorders with a hypertonicity component.