There are many types of arthritis, but most often in the shoulder it is triggered by an initial trauma. It can also involve “wear and tear” of the tissues of the joint, causing inflammation, swelling and pain. Often people will react by instinctively limiting their shoulder movements in order to lessen the pain. This can lead to a tightening or stiffening of the soft tissue parts of the joint, resulting in yet further pain and restriction of motion. In the worst cases, adhesive capsulitis occurs and the arm can not be moved.
Doctors at the Mayo Clinic, published July 2022 recommendations (1) for the treatment of shoulder osteoarthritis. They write: “Glenohumeral osteoarthritis has proven to be a major contributor to shoulder joint pain and dysfunction in the elderly. There are several conditions about the shoulder that contribute to the development of glenohumeral osteoarthritis, which includes traumatic injuries, rotator cuff pathology, glenohumeral instability, glenoid dysplasia, and osteonecrosis. When glenohumeral osteoarthritis pain is refractory to conservative treatment, intra-articular injections and surgery can be performed. The radiologist should be aware of the varying types of shoulder arthroplasties, what preoperative findings influence that decision and the expected postoperative appearance of the differing components.”
1 Stanborough RO, Bestic JM, Peterson JJ. Shoulder Osteoarthritis. Radiol Clin North Am. 2022 Jul;60(4):593-603. doi: 10.1016/j.rcl.2022.03.003. PMID: 35672092.