Short-term outcomes after hybrid unicompartmental knee arthroplasty: A retrospective cohort study with minimum 3-year follow-up.

This study aims to evaluate the survival rate and short-term clinical outcomes of hybrid unicompartmental knee arthroplasty (UKA). We retrospectively analyzed 155 Oxford phase-3 hybrid UKAs in 155 patients who were followed for more than 3 years. Kaplan-Meier survival curves were generated using revision as an endpoint. Oxford knee score (OKS) and range of motion (ROM) were evaluated for clinical assessment, and radiographs were used to assess implant-related complications. At an average follow-up of 3.6 years (range, 3-6 years), 2 knees required revision. The reasons for revision were bearing dislocation and unexplained pain. The overall survival rate was 98.7% at the 6-year follow-up. The mean OKS decreased from 40.94 ± 4.86 to 14.84 ± 1.39 at the last follow-up (P < .001). The mean OKS showed a significant improvement during the first 2 years. The mean ROM improved from 104.81 ± 10.03° to 114.93 ± 7.51° at the last follow-up (P < .001). The mean ROM increased during the first 3 years. Radiolucent lines were observed in 6 cases at 6 years postoperatively, affecting 4 knees. At 6 years postoperatively, the following complication rates were observed: overall revision rate: 1.33% (2/150); deep vein thrombosis rate: 3.33% (5/150); chronic soft tissue pain rate: 1.33% (2/150); stiffness rate: 0.67% (1/150); prosthesis dislocation rate: 0.67% (1/150); lateral meniscus injury rate: 0.67% (1/150); lateral arthritis progression rate: 2.67% (4/150). Oxford phase-3 hybrid UKA provides good survival rates and clinical outcomes in the short-term follow-up.