Ten year outcomes for the prospective randomised trial comparing unlinked, modular bicompartmental knee arthroplasty and total knee arthroplasty

Background A sizeable proportion of knee osteoarthritis is limited to the medial and patellofemoral compartments. Whilst short- and medium-term studies comparing bicompartmental knee arthroplasty (BCA) and total knee arthroplasty (TKA) have shown similar outcome scores, there are no studies comparing long-term outcomes. This study aims to determine which procedure resulted in superior long-term outcome scores. Methods Forty-eight patients with medial and patellofemoral compartment knee osteoarthritis were randomised to receive treatment in two groups: unlinked, modular BCA and TKA. The main outcome measures compared were the range of motion, Knee Society Function Score, Knee Society Knee Score, Oxford Knee Score, Physical Component Score and Mental Component Score of SF-36 pre-operatively and post-operatively up to 10 years. Radiographs of the operated knees were taken pre-operatively, post-operatively and at 10-year follow-up. Results Twenty-six underwent BCA and 22 underwent TKA. Overall improvement was seen in both groups compared to pre-operatively, however there were no significant differences detected between the groups at 10 years. The median Hip–Knee–Ankle (HKA) angle was 183.38 (175.17–187.94) in the BCA group and 180.73 (174.96–185.65) in the TKA group. One patient from the BCA group had a peri-prosthetic fracture necessitating revision surgery to a TKA. Conclusions Outcome scores for BCA results were comparable to TKA at long-term follow-up. BCA is an alternative arthroplasty option in selected patients.