Unicompartimental Knee Arthroplasty In Patients With or Without Patellofemoral Arthritis: 2-Year Clinical Outcome

Abstract

Objectives Evaluate patients submitted to unicompartimental knee arthroplasty (UKA) by two surgeons with partial knee replacement expertise and, analyze the outcomes comparing a group of patients with preoperative isolated medial compartment arthritis to another group of patients with associated patellofemoral arthritis. Methods We conducted a retrospective cohort study to compare the clinical results of all patients submitted to UKA by two senior surgeons, between 2009 and 2020. All patients were submitted to partial knee arthroplasty using fixed-bearing Zimmer Unicondylar Knee System (ZUK). During analysis, they were divided into two groups, without patellofemoral arthritis (Group 1) and with patellofemoral arthritis (Group 2). Data collected from patient’s records included demographic information, range of motion (ROM), patient-reported outcome measures (PROMs) and preoperative radiographs. Only patients with minimum 2-year follow-up were included. Results Preoperative ROM was 122.6º (±6.2º) and 122.2º (±9.2º), in Group 1 and in Group 2, respectively (p-value = 0.9). While postoperative ROM was 114.5º (±2.9º) in Group 1 and 112.5º (±3.6) in Group 2 and, there was no statistical significance (p-value = 0.4). There was also no statistical significance regarding PROMs (Table 3). In Group 1, Oxford Knee Score was 17.1 (±1.8) and 40.2 (±2.1), before and after surgery, respectively. In Group 2, Oxford Knee Score changed from 18.8 (±1.9) to 40.5 (±2.5). The KOOS went from 129.3 (±15.2) preoperatively to 61.4 (±18.3) after surgery, in Group 1, while Group 2 evolved from 137.2 (±14.8) to 57.3 (±11.9). No complications were identified during the period studied. Conclusion UKA is an acceptable treatment option for unicompartimental tibiofemoral arthritis of the knee in patients with associated PFOA. There was an improvement in ROM of the knee, Oxford Knee Score and KOOS, with no differences between patients with or without PFOA.