Lateral and Medial Unicompartmental Knee Arthroplasty Have Similar Reoperation Rates, Patient-Reported Outcomes, and...

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Clinical Outcomes Research

Background:

• Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty for isolated knee osteoarthritis.
• Medial and lateral compartment knee osteoarthritis require distinct surgical approaches.
• Comparative outcome data between LUKA and MUKA is limited.

Purpose of the Study:

• To compare the 2-year postoperative outcomes of lateral unicompartmental knee arthroplasty (LUKA) versus medial unicompartmental knee arthroplasty (MUKA).
• To evaluate functional recovery, patient-reported outcomes, and complication rates between LUKA and MUKA.

Main Methods:

• Retrospective cohort study of adult patients undergoing UKA between 2018-2022.
• Propensity score matching was used to balance cohorts on age, sex, BMI, and surgical year.
• Comparison of preoperative and postoperative range of motion, KOOS, PROMIS physical function, reoperation rates, and complications.

Main Results:

• No significant differences in Knee Injury and Osteoarthritis Outcome Score (KOOS) or PROMIS physical function between LUKA and MUKA at any time point up to two years.
• Reoperation rates were similar, with two conversions to total arthroplasty for LUKA and one for MUKA.
• All-cause emergency department returns and infections requiring irrigation and debridement were comparable between the two groups.

Conclusions:

• LUKA and MUKA provide equivalent functional improvement and patient-reported outcomes within two years post-surgery.
• Rates of reoperation and infection are similar for both LUKA and MUKA.
• Findings support the use of LUKA as a viable surgical option and help manage patient expectations for 2-year outcomes.