Clinical evidence of novel arthroplasty implants: the essential contribution of implant migration analysis

Abstract

This thesis investigates how radiostereometric analysis (RSA) can improve patient safety by providing objective evidence on the performance of new arthroplasty implants. RSA measures implant migration, which reflects implant-bone fixation, whereas patient-reported outcome measures (PROMs) assess patient-perceived performance. First, in a study of 300 total knee arthroplasty (TKA) patients across five RSA trials, no association was found between implant migration and PROMs, indicating they measure distinct aspects of implant performance. Second, we performed two randomized controlled trials using RSA to compare different implant designs: one in total hip arthroplasty and one in total knee arthroplasty. Third, a methodological study showed that different RSA marker-selection methods affect individual measurements but not group-level results. Fourth, a systematic review of all recent RSA studies on implant migration revealed only moderate adherence to current guidelines, prompting recommendations to improve future reporting. Finally, registry data from the Netherlands showed no reduced long-term revision risk in RSA-tested TKA implants, likely due to existing national quality controls for all TKA implants. Overall, RSA provides valuable early evidence on implant performance, but requires standardized use and reporting to optimize its clinical impact.