COPELAND SURFACE REPLACEMENT ARTHROPLASTY FOR AVASCULAR NECROSIS OF THE HUMERAL HEAD

Abstract

Avascular necrosis (AVN) of the humeral head is an extremely disabling condition (Gerber et al, JSES 1998. 7(6):586–90). The results of stemmed arthroplasty for this condition are good, with Hattrup and Cofield reporting 79% subjective improvement at nine years (JSES 2000;9:177–82). This study reports the outcomes of surface replacement shoulder arthroplasties for AVN over a 16 year period. Between 1986 and 2001 twenty-seven arthroplasties were performed in patients with advanced avascular necrosis of the humeral head. All patients had secondary degenerative changes. AVN was secondary to corticosteriods and trauma in most cases.

The mean age of the patients was 60 years (range 35 to 86). These included 16 hemiarthroplasties and 7 total shoulder arthroplasties. All prostheses were of the Copeland Surface Replacement Arthroplasty (CSRA) type.

The average follow up period was 6 years (range 1 to 13). The average preoperative Constant score was 17. This improved to 74 at follow-up. Forward flexion improved from 63 degrees preoperatively to 133 degrees at follow-up. Abduction improved from 49 degrees to 118 degrees. External rotation improved from −3 degrees to 61 degrees. Pain scores improved from 0 to 11.7, using a 15 point visual analogue scale. 81% of patients had slight and no difficulty performing their routine activities of daily living. The remaining 19% still had some difficulty with routine activities. Four of the patients performed regular overhead activity and recorded some difficulty in doing this, whereas they had great difficulty pre-operatively. There were no cases of loosening. No difference was seen in any of the results between the hemi-arthroplasty and total shoulder replacement patients.

Surface replacement arthroplasty is a suitable procedure for degenerative disease secondary to AVN of the humeral head, with results similar to stemmed prostheses. It has the advantage of preserving bone stock.