Deltoid muscle injury scratched by an osteophyte on the greater tuberosity of the humeral head: an unusual cause of shoulder pain.

Few reports to date have discussed acute deltoid muscle injury, including partial or complete deltoid muscle detachment from its origin. The present report describes a different pathomechanism and clinical manifestations of deltoid muscle injury. A 52-year-old man experienced acute severe pain in the right shoulder as a result of abrupt elevation of the arm. The deltoid muscle had apparently been scratched by an osteophyte on the greater tuberosity. After arthroscopic excision of the osteophyte, the symptoms resolved completely.