Abstract Purpose The benefit of patella resurfacing (PR) in primary total knee arthroplasty (TKA) remains debated. While outcomes appear similar, unsurfaced patellae show higher revision rates. Existing studies are limited by heterogeneous cohorts. This study assessed the risk of secondary PR in relation to the level of constraint and primary procedure complexity (idiopathic vs. posttraumatic osteoarthritis). Methods Using registry data, 258,669 primary TKAs without primary PR were analysed. Demographics, implant constraint and subsequent revisions were recorded. The primary endpoint was secondary PR (without additional femoral or tibial implant removal) over a follow‐up period of up to 8 years. Results Cruciate‐retaining (CR) designs showed the lowest revision risk (ca. 1%), whereas posterior‐stabilised (PS) designs showed the highest (ca. 2.0–2.5%, hazard ratio = 1.8 95% confidence interval = 1.66–1.99, p < 0.001). The majority of secondary PR occurred within 4 years. No differences were found between idiopathic and posttraumatic groups. Conclusions Registry data indicate higher revision risk with PS versus CR designs, regardless of index surgery complexity. Level of Evidence Level III.
Kirschbaum et al. (2026) studied this question.