Adjustable stemmed shoulder hemiarthroplasty: Ten-year results of a prospective multicentre study

Abstract

BackgroundAdjustable shoulder hemiarthroplasty (HA) allows the complex anatomy of the proximal humerus, including its centre of rotation, to be restored. However, whether better anatomical adaptation improves clinical outcomes and long-term survival remains unclear. Therefore long-term clinical and radiographic results of an eccentric adjustable hemiprosthesis were examined, focusing on the longevity and fixation of the humeral stem. HypothesisAdjustable shoulder HA enhances long-term functional outcomes and reduces complications. Materials and methodsIn this prospective multicentre study, 120 HAs were performed using a stemmed hemiprosthesis on 115 patients. The clinical and radiologic outcomes were measured at 3, 6, 12, and 24 months, and thereafter at 4, 7, and 10 years with a median follow-up period of 7.7 years (92.3 months, range 2.6–148.5 months). Revision-free survival rates were calculated up to 10 years postoperatively. ResultsThe mean Constant-Murley score increased over the first 24 months from 26.2±9.0 to 61.0±17.3 points, then levelled off until the final follow-up. Patients with humeral head necrosis had the best clinical outcomes, while patients with fracture sequelae and rheumatoid arthritis had the worst. Although radiolucent lines were more frequent after cemented fixation, lines of>2mm only occurred after uncemented fixation. Finally, five cases required secondary glenoid implantation, and survival free from stem revision was 99.0% (95% confidence interval [CI], 92.8%–99.9%) at 4 years, 97.6 (95% CI, 90.6%–99.4%) at 7 years, and 92.2% (95% CI, 81.9%–96.8%) at 10 years. DiscussionThe study showed that adjustable shoulder HA is a safe and effective treatment option for various degenerative disorders of the shoulder joint. Functional scores first increased, then levelled off after 24 months. Moreover, revision-free survival compared well with previously reported values. Observed stable long-term results confirm that adjustable shoulder HA has beneficial clinical outcomes and a low complication rate.