Abstract
In the United Kingdom's National Joint Registry 2018 Annual Report, the combination of a POLARSTEM hip stem and R3 acetabular component has the lowest revision rate of any total hip arthroplasty (THA) construct combination at 7 years. Although revision rates remain a crucial measure of an implant combination's performance, there is increasingly more attention being given to patient-reported outcome measures (PROMs), which often reflect the endpoints that patients’ themselves consider of paramount importance in choosing to undergo THA. Therefore, the current analysis was undertaken to better understand the PROMs-based performance of this combination. Bespoke implant reports were requested for the POLARSTEM/R3 combination with OXINIUM™ heads and highly cross-linked polyethylene (XLPE) bearing. Reports used data from the National Health Service PROMs programme, which collected the Oxford Hip Score (OHS), EQ-5D and EQ-VAS. Health gain scores, calculated as differences between preoperative and 6-month post-operative scores, were adjusted to account for any differences in patient demographics between comparative groups. The mean OHS adjusted health gain score for the construct combination was 22.8 (95% confidence interval [CI]: 22.4 – 23.1; n = 1799 patients) compared to 21.2 (95% CI: 21.2 – 21.3; n = 111,055). For EQ-5D, the scores were 0.462 (95% CI: 0.451 – 0.473; n = 1685) for the construct and 0.434 (95% CI: 0.433 – 0.436; n = 102,448) for the class average. For EQ-VAS, the construct had adjusted scores of 14.2 (95% CI: 13.4 – 14.9; n = 1605) compared to the class average of 11.4 (95% CI: 11.3 – 11.5; n = 98,610). There were also more patients who rated their satisfaction as ‘excellent’ in the specific construct group. Comparisons were statistically significant in all cases (p < 0.001). In conclusion, in addition to excellent mid-term survivorship, the POLARSTEM/R3 construct combination has demonstrated superior PROMs that may improve patient outcomes.
