Which do patients prefer, unicompartmental or total knee arthroplasty?

Abstract Objective Unicompartmental knee arthroplasty (UKA) is a viable option for relieving pain and improving function in patients with isolated compartment knee osteoarthritis (OA). Certain surgeons prefer total knee arthroplasty (TKA) over UKA even when patients are candidates for UKA. Therefore, the decision to perform a UKA or a TKA when both are indicated is not straightforward. The goal of this study was to compare pre-operative and post-operative patient-reported outcome (PRO) scores for patients who underwent both a UKA and a contralateral TKA. Methods In this study, 17 patients were identified who underwent UKA in one knee and TKA in the contralateral knee either simultaneously or at different time points between 2003 and 2014. All procedures were performed by one of two fellowship trained surgeons at a large academic medical center. Patients were evaluated pre-operatively and then post-operatively using the validated PRO measurements Short Form 12 (SF12), Knee Society Functional Score (KSS), and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) questionnaires. Student’s paired t -tests were conducted to compare PRO scores for UKA and TKA pre-operatively and post-operatively. Results Post-operatively, mean follow-up was 2.5 years (range, 3 months to 9 years). There was no significant difference in PRO scores between pre-operative values for UKA and TKA, and no significant difference between post-operative values for UKA and TKA (e.g. SF12 pre-operative difference between UKA and TKA mean = 1.6, p = 0.57; SF12 post-operative difference between UKA and TKA mean = 1.9, p = 0.51). Conclusion UKA and TKA are comparable in terms of PROs at mid-term follow-up. When choosing between UKA and TKA, the surgeon should expect similar PROs for each, and can therefore take into account other considerations when making a selection.