Hemiarthroplasties procedures

The modern era of shoulder replacement was ushered in by Dr. Charles Neer, II. In 1953, in response to the relatively poor results of humeral head resection for patients with proximal humeral fractures. Dr. Neer implanted a vital-hum humeral component of his own design in a hemiarthroplasty procedure (Figure 9.4). In 1955, he reported on his first series of 12 pahents treated in this way. 

The number of shoulder arthroplasty procedures done yearly has grown from an estimated 5000 per year in the United States between 1990 and 1992 (Wirth and Rockwood, Jr. 1996) to around 15,000 per year between 2002 and 2003 (Jackson 2003). Of these, a substantial portion are hemiarthroplasties. The prevalence of hemiarthroplasties as a percentage of the total number of replacements ranges from 14% (Edwards et al. 2002) in a multicenter study of OA, to 65% in a study of fracture repair (Boileau et al. 2001), to 87% in the Swedish shoulder arthroplasty register started in 1999 (Rahme, Jacobsen, and Salomonsson 2(X)1). Dr. Charles Neer, II, the pioneer of tiie procedure, estimates that overall, aroimd 20% of shoulder replacements are hemiarthroplasties (2003). 

BiPolar. A modular head with a cobalt chromium shell and an inner UHMWPE bearing surface and retaining ring capturing an inner cobalt chromium head. The concept was originally developed in the 1970s and was intended for use in a hemiarthroplasty salvage procedure. 

In either case, to replace the humeral articular surface, the humeral head is resected at its base and the medullary cavity of the proximal humeral bone is prepared to accept the stem of a metal humeral prosthesis. In a fracture repair procedure, the bone fragments are reapproximated and held in place around the stem and under the head of a metal humeral component by wires. Many humeral components include holes in the stem to faciUtate this reattachment. One type of humeral component used in hemiarthroplasty... 

---