HEMIARTHROPLASTY FOR GLENOHUMERAL ARTHRITIS WITH MASSIVE ROTATOR CUFF TEARS

Shoulder motion and function are dependent both on congruent articular surfaces and an intricate balance of muscle forces about the glenohumeral joint. Owing to its lack of intrinsic stability, the glenohumeral joint is more dependent than any other joint on muscle forces to provide both stability and function. Compromise of joint congruity or rotator cuff integrity can result in severe pain and functional limitation. The presence of glenohumeral arthritis and rotator cuff tears in the same shoulder, as is seen in cuff-tear arthropathy 10,11,42 or rheumatoid arthritis, is one of the most challenging clinical situations facing the reconstructive shoulder surgeon. The association of glenohumeral arthritis and rotator cuff deficiency has been recognized for many years. In 1853, John Gregory Smith described the pathoanatomic changes observed in the shoulder of an elderly woman suffering from shoulder pain for many years. His description was as follows: "upon removing the deltoid muscle, the naked head of the humerus, elevated to the acromion process, came into view the centre of its summit was devoid of cartilage over the space as large as a shilling and covered with ivory-like deposit." 12,53 Modern recognition of this disease process as a distinct clinical entity is credited to Charles Neer II, who introduced the concept of cuff arthropathy in 1977. McCarthy et al described a similar clinical entity in 1981, which was termed the Milwaukee shoulder. 38 This report postulated that this clinical entity was caused by a degenerative process initiated by the presence of hydroxyapatite crystals. In 1983, Neer et al published the classic article on cuff tear arthropathy, in which the pathoanatomic changes observed in this disease process were described. 42 Unlike McCarty et al, Neer believed that the changes seen in cuff tear arthropathy were the result of massive rotator cuff deficiency. Defective rotator cuff function results in superior migration of the humeral head and inactivity, leading to impaired cartilage nutrition, osteoporosis, and collapse of segments of articular cartilage. It is the authors' belief that there are three distinct clinical entities that have the components of glenohumeral arthritis and rotator cuff tendon tears. The most common of these entities is rheumatoid arthritis. The inflammatory process of the diseased synovium causes rotator cuff tears and destruction of articular surfaces. In rotator cuff arthropathy, there is an inflammatory process that involves both the rotator cuff tissue and the glenohumeral joint. There is significant bone erosion and osteoporosis. The rotator cuff tear is massive, with atrophic tissue, and the biceps tendon is often ruptured. A third group of patients have osteoarthritis of the glenohumeral joint independent of rotator cuff tears. All the sequelae of osteoarthritis including sclerosis, joint space narrowing, and osteophyte formation are observed. The quality of the rotator cuff tissue is good, and repair is usually possible. This clinical entity, distinct from rotator cuff arthropathy, may become more common as the population ages and remains more active. Numerous reconstructive procedures have been proposed to treat this disease process, including resection arthroplasty, arthrodesis, constrained arthroplasty, semiconstrained arthroplasty, bipolar arthroplasty, total shoulder arthroplasty, and hemiarthroplasty. It has been the authors' experience that hemiarthroplasty with partial repair of the rotator cuff provides excellent pain relief while optimizing function.