Contemporary cementless patellar resurfacing in total knee arthroplasty is associated with a low early complication rate across residual bone thicknesses

Purpose The aim of this study was to evaluate early clinical and radiographic outcomes of primary total knee arthroplasty (TKA) with patellar resurfacing using contemporary cementless fixation, with emphasis on early complications, revision risk, residual patellar bone thickness, and its relationship to fracture risk. Methods A retrospective review was performed on 323 primary TKAs with cementless patellar resurfacing performed between 2021 and 2024. Patients with follow‐up less than 12 months were excluded. Outcomes included fracture and revision rates, osteolysis, pre‐ and postoperative patellar thickness, and residual bone thickness. Paired t‐tests with mean difference (MD) were used to compare patellar measurements. Interclass correlation coefficient for residual bone thickness was 0.92 ( p = 0.009). Logistic regression was performed to assess the association between residual bone thickness and fracture risk. Results Mean follow‐up was 36 months (range, 16–67 months). No patellar revisions were performed. Two fractures occurred (0.6%), both managed conservatively, and no aseptic loosening or implant migration was observed. Radiographic osteolysis was identified in 11 patients (3.4%), with 19 osteolytic patterns distributed across four anatomical regions, most commonly the lateral quadrant. Full patellar thickness showed a small postoperative reduction (MD −0.77 mm, p < 0.001). Mean postoperative residual bone thickness was 13.5 mm (range, 9–17.7 mm). Fracture cases had lower residual bone thickness compared with non‐fracture cases (MD −1.4 mm, p < 0.001). There were no intraoperative fractures for the entire cohort. Conclusion Contemporary cementless patellar resurfacing demonstrates excellent early clinical and radiographic outcomes, with minimal complications and no revisions. No fractures occurred in patellae with residual thickness <12 mm; however, given the limited number of fracture events, no definitive conclusions can be drawn regarding a thickness threshold and fracture risk. Level of Evidence Level IV.