Revision of humeral head and total shoulder arthroplasties.

A prospective study was undertaken of 40 revisions of humeral head and total shoulder arthroplasties performed during the past nine years. The average follow-up period was 42 months. Surgical revision consisted of conversion to unconstrained total shoulders in 34 shoulders, fixed-fulcrum total shoulder in one shoulder, and "cleanout" of the implant and cement in five shoulders, of which three were later fused. The indications for fusion were (1) infection, and (2) extensive loss of shoulder muscles, including both the deltoid and rotator cuff. Neither loss of bone nor rotator cuff defects were considered contraindications to unconstrained total shoulder arthroplasty; however, the results of this study emphasize the need for a good initial humeral head arthroplasty, insofar as the function of revisions is often impaired by muscle damage, bone loss, and scar.