Satisfaction and Functional Outcomes in Unicompartmental Compared with Total Knee Arthroplasty: Radiographically Matched Cohort Analysis

Methods: One hundred and thirty-five UKAs and 135 TKAs were matched by patient age, sex, body mass index, and American Society of Anesthesiologists Physical Status (ASA-PS) classification as well as preoperative osteoarthritis severity in medial and lateral tibiofemoral and patellofemoral compartments (Kellgren-Lawrence grading system). Patient-reported outcome measures for pain, function, activity level, and satisfaction were evaluated at minimum 1-year follow-up via components of the modern Knee Society Score, the University of California Los Angeles (UCLA) activity-level score, and a Likert satisfaction scale.

Results: The patients in the UKA group reported significantly less pain, a higher activity level, and greater satisfaction while performing several functional activities and could walk for a longer amount of time before stopping due to knee discomfort compared with those in the TKA group (p ≤ 0.038). In addition, a greater proportion of patients in the UKA than in the TKA group were "satisfied or very satisfied" with their knee replacement surgery at minimum 1-year follow-up (90% versus 81%; p = 0.043).

Conclusions: With minimum 1-year follow-up, patients who underwent UKA reported significantly higher function, less pain, and a greater level of patient satisfaction than a radiographically and demographically matched TKA cohort.

Level Of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.