Hybrid Fixation Achieves Similar or Slightly Better Results Compared With All Cemented Fixation in Oxford Unicompartmental Knee Arthroplasty at the Short-Term Follow-Up

Introduction Cementless Oxford unicompartmental knee arthroplasty (OUKA) has been shown to have less frequent radiolucent lines and equivalent or even better results than those of cemented OUKA. However, tibial fractures are more frequent in cementless OUKA than in cemented OUKA, especially in Asian countries. A hybrid option, with a cementless femur and cemented tibia, may, therefore, be a good compromise. This study compares the clinical results of hybrid OUKA with those of fully cemented OUKA. Materials and methods This retrospective study included 108 consecutive unicompartmental knee arthroplasties implanted between September 2016 and September 2018 in our hospital. Cases were divided into two groups: those using cemented fixation and those using hybrid fixation OUKAs. Pre- and postoperative knee range of motion (ROM), operation time, pre-and postoperative Oxford knee score (OKS), and complications were compared between the groups two years after OUKA was performed. Results There was no significant difference in pre- and postoperative ROM, operation time, and OKS performed unilateral OUKA, but mean OKS was higher in the hybrid group than in the cemented group performed bilateral OUKA (p<0.01). Both groups included one revision to total knee arthroplasty each. There was no statistically significant difference in the rate of revision (p=0.723). Conclusions Better clinical outcomes were achieved in the hybrid fixation group than in the cemented fixation group, with an equivalent rate of complication. Longer follow-up periods are needed to confirm the benefits of hybrid fixation in OUKA over time.