Outcome of Unicondylar Knee Arthroplasty vs Total Knee Arthroplasty for Early Medial Compartment Arthritis: A Randomized Study

Background With increasing number of patients with early osteoarthritis of knee opting for total knee arthroplasty (TKA), there has been increase in patients dissatisfied with surgical outcomes. It is being presumed that offering unicondylar knee arthroplasty (UKA) to them would improve outcomes. Methods Primary objective of our study was to look for any difference in patient-reported outcome and function at 2-year follow-up in patients undergoing UKA as compared to TKA. Our study was a randomized study with parallel assignment conducted at a high-volume specialized arthroplasty center. Eighty patients with bilateral isolated medial compartment knee arthritis were randomized into simultaneous 2-team bilateral TKA (n = 40) and UKA (n = 40) group. We finally analyzed 36 patients in each group. Main outcome measure was improvement in Knee Outcome Survey-Activities of Daily Living Scale (KOS-ADLS) and High Activity Arthroplasty Score (HAAS) obtained at 2-year follow-up. Results Improvement in KOS-ADLS and HAAS at 2 years was similar ( P = .2143 and .2010) in both groups. Performance as assessed with Delaware index was also similar. Length of hospital stay was less in UKA group (6.6 days as against 5.4 days). Complications and readmission rates were more in TKA group (nil in UKA group; 08 in TKA group). Conclusion At 2-year follow-up, UKA provides similar improvement in patient-reported outcomes, function, and performance as compared to TKA when performed in patients with early arthritis. However, UKA patients have shorter hospital stay and fewer complications.