Unconstrained shoulder arthroplasty. A five-year average follow-up study.

A series of 42 total shoulder arthroplasties and four humeral hemiarthroplasties were performed with either the English-McNab or Neer prosthesis. Retrospective follow-up study averaged five years with a three-year minimum. Preoperative diagnoses included rheumatoid arthritis, osteoarthritis, posttraumatic arthritis, rotator cuff arthropathy, avascular necrosis, failed prosthesis, and congenital dislocation. Postoperatively, pain improved in 94% of shoulders, and active range of motion improved an average of 42 degrees in abduction and 47 degrees in forward flexion. Rotator cuff lesions were correlated with poorer postoperative function. Complications developed in four shoulders (9%) and consisted of humeral component protrusions (two shoulders), loosened prosthesis (one shoulder), and unrecognized, preoperative tuberculous infection (one shoulder). Fifteen glenoid components (36%) and six humeral components (13%) developed lucent lines roentgenographically, but only one glenoid component developed migration.