Humeral head replacement for the treatment of osteoarthritis.

BACKGROUND

Humeral head replacement has been used successfully for the treatment of osteoarthritis of the shoulder for decades. The purpose of this study was to define the results of this form of treatment, the risk factors for an unsatisfactory outcome, and the rates of failure over time.

METHODS

Between 1978 and 1997, sixty humeral head replacements were performed at our institution for the treatment of osteoarthritis. Five patients (seven shoulders) died less than five years postoperatively, and one patient (two shoulders) was lost to follow-up. Fifty-one humeral head replacements in forty-nine patients with a complete postoperative evaluation and operative records who had been followed for a minimum of five years (mean, 11.3 years) or until revision were included in the study. All sixty shoulders were included in the survival analysis.

RESULTS

Overall, there was significant long-term pain relief (p<0.0001) as well as improvement in active abduction (p<0.0001), internal rotation (p<0.024), and external rotation (p<0.0001) following the humeral head replacement. However, moderate pain was reported in nine shoulders and severe pain, in seven. Ten of the fifty-one shoulders underwent revision surgery, which was done to treat painful glenoid arthrosis in nine of the ten. Radiographs were available for thirty-nine shoulders, and they demonstrated an increase in glenoid erosion at a mean of 10.7 years postoperatively (p<0.0001). Five shoulders had humeral periprosthetic lucent lines of 1.5 mm in thickness, and three of them had a complete line; one humeral component had shifted in position. According to a modification of the Neer result rating system, there were ten excellent results, twenty satisfactory results, and twenty-one unsatisfactory results.

CONCLUSIONS

Substantial clinical improvement can occur after humeral head replacement for osteoarthritis of the shoulder, but there is a high rate of unsatisfactory results and revision surgery. The decision as to whether this is the optimal surgical procedure for the treatment of osteoarthritis of the shoulder requires careful consideration.