Results of a new stemless shoulder prosthesis: radiologic proof of maintained fixation and stability after a minimum of three years' follow-up.

摘要

HYPOTHESIS: In total shoulder arthroplasty, the humeral component, particularly the stem, can be involved in some of the complications and technical difficulties increase in posttraumatic arthritis with proximal humeral malunion. To decrease the intraoperative complications related to the stem, the TESS (Biomet Inc, Warsaw, IN) humeral implant, was designed in 2004 hypothesis that we can obtain a good fixation with a stemless prosthesis. This investigation reports the preliminary results of this prosthesis with more than 3 years of follow-up. METHODS: Between March 2004 and June 2005, 70 patients underwent 72 shoulder replacements with the TESS humeral prosthesis. Sixty-three patients were reviewed with a follow-up of more than 36 months (average, 45.2 months; range, 36-51 months). The mean preoperative Constant score was 29.6. RESULTS: Gain in active mobility was 49 degrees for forward flexion and 20 degrees for external rotation. The postoperative Constant score was 75. Radiographic analysis showed no radiolucencies or implant migration. Functional results are comparable with previous reports on prosthetic glenohumeral replacement. DISCUSSION: Our clinical results are similar to this with classical prosthesis. The humeral head removal facilitates the glenoid exposure and implantation. After the initial cases any specific complication was seen. CONCLUSIONS: Owing to the automatic central positioning of the implant, an anatomic reconstruction was achieved. In malunions, no tuberosity osteotomy was required. At 3 years of follow-up, there is radiologic evidence of maintained implant stability. These encouraging preliminary results confirm our belief that a stemless prosthesis can be used to obtain an anatomic reconstruction of the proximal humerus. A longer-term follow-up study is needed to validate these results.