Die CUP-Prothese mit einer zementierten Schultergelenkpfanne im Vergleich zur konventionellen anatomischen Totalendoprothese – eine Matched-Pair-Analyse

Abstract

The purpose of this clinical study (matched-pair design) was to compare the functional short-term results obtained in patients with surface replacement of the humeral head and cemented glenoid prosthesis with those obtained after total shoulder arthroplasty. 20 patients (average age 67.7 [43-85] years, 17 women, three men) who received surface replacement of the humeral head with cemented glenoid prosthesis were matched to a control group of 20 patients (average age 67.55 [42-85] years, 17 women, three men) with a conventional total shoulder arthroplasty. Six patients were treated for osteoarthritis, two for post-traumatic arthritis, 1 each for osteonecrosis and rheumatoid arthritis. Preoperative status, perioperative results and postoperative status (Constant score, subjective assessment, range of motion, radiographic evaluation) were compared in all patients and controls. The adjusted Constant score improved from a mean of 37.25% to a mean of 87.75% in the hybrid group and from a mean of 30.8% to a value of 87.1% in the TSA group. Regarding the relative improvement at 12 months compared to baseline, patients treated with hybrid prostheses showed a comparable benefit in the Constant score, pain reduction and range of motion. Only the criterion "strength" revealed a significantly better result in the TSA group (p = 0.025). There was one irreversible injury of the brachial plexus in one case and neural injuries with a full recovery in two cases of Hybrid prosthesis. The combination of humeral surface replacement with cemented glenoid component offers a relatively new option for the treatment of different pathologies at the shoulder joint which need a total joint substitute.The short-term results are comparable with those of conventional total shoulder arthroplasty. Surface replacement of the shoulder facilitates later revision because of less loss of bone stock. It must be considered that surface replacement with implantation of cemented glenoid prosthesis is a difficult procedure because of the exploration of the glenoid.