The experience of stemmed pyrocarbon shoulder hemiarthroplasty in New Zealand : ten years of registry data.

Abstract

Pyrocarbon has been used as a bearing surface in hemiarthroplasty (HA) of the shoulder for more than a decade. The use of pyrocarbon is thought to reduce the rate of glenoid erosion compared with metal HA, and reduce the risk of glenoid complications compared with anatomical total shoulder arthroplasty (aTSA). However, there is little information about the long-term outcomes. The aim of this study was to investigate the use of pyrocarbon HA (PyCHA) in New Zealand, and the clinical outcomes and revision rates. The New Zealand National Joint Registry was used to obtain data on all patients undergoing HA of the shoulder with a stemmed PyCHA. Data which were assessed included the indication for surgery, patient-reported outcome scores, and revision rates. Between January 2014 and December 2024, 288 stemmed PyCHAs were recorded in 277 patients, with a mean age of 55 years (20 to 86). The mean follow-up was 50 months (3 to 128). The use increased 2.3-fold during the study period. The most common indication for surgery was osteoarthritis (OA) (154 (53.5%)), followed by avascular necrosis (AVN) (52 (18.1%)), the sequelae of trauma (48 (16.7%)) and after recurrent dislocation (38 (13.2%)). The mean Oxford Shoulder Score (OSS) was 36.4 (SD 8.2) six months postoperatively, increasing to 40.8 (SD 7.9) at five years. The revision rate was 0.75 per 100 component-years (95% CI 0.34 to 1.42). The mean six-month OSS was significantly lower in the sequelae of trauma group than in the OA (p = 0.014) or AVN groups (p = 0.020). The use of PyCHA is increasing in New Zealand. It is typically used in younger patients with OA. It has good clinical outcomes and low revision rates at mid-term follow-up. Further study is needed to assess the ideal indications for this procedure and the long-term clinical outcomes and revision rates.