Large metaphyseal volume hemiprostheses for complex fractures of the proximal humerus.

Abstract

Results of hemiarthroplasty after acute complex proximal humerus fractures are controversial. The main problem is the fixation and healing of the greater tuberosity (GT). To address this problem a hemiarthroplasty with a large metaphyseal volume was designed and introduced. Thirty hemiarthroplasties were implanted for acute, complex, proximal humeral fractures in 30 consecutive patients (average age: 63.3 years; range, 41-78). One patient was lost; 2 patients could only be interviewed telefonically. Two patients had to be revised because of secondary displacement of the GT within the first 2 postoperative years. The remaining 25 patients were assessed clinically, radiographically, and with computer tomography (CT) imaging after a mean of 25 months (range, 24-29). Greater tuberosity healed in situ in 23 patients. In 12 cases, CT documented severe resorption of GT without displacement of a measurable bone fragment and an intact clinical cuff function with a radiographically preserved acromio-humeral distance. The mean Constant score was 59 points (range, 26-81), the mean relative Constant score 75% (range, 31-100). The mean anterior elevation was 117° (range, 45-160). The mean subjective shoulder value was 70% (range, 25-98). In 4 cases (14%), tuberosity dislocation occurred which was associated with an increase of fatty infiltration and poor result. The 2-year results with a large metaphyseal volume fracture-prosthesis showed good to excellent results, with a failure rate of 14%. Substantial resorption of the greater tuberosity was frequent, but was not associated with functional incompetence of the rotator cuff. The overall results obtained justify its continued use.