Abstract
Purpose
The most common procedure for advanced osteoarthritis of the knee is a total knee arthroplasty (TKA). Unicompartmental knee arthroplasty (UKA) has become a popular treatment for isolated medial compartment osteoarthritis. The purpose of this study was to look at the functional outcomes following these two procedures.
Method
Prior to January 1995, 87 Miller-Galante UKAs (MG UKA) were performed in 68 patients. These were compared to a gender, age, BMI matched Anatomic Modular Knee (AMK) cohort of equal size performed during the same time period. Patients were evaluated using a validated clinical outcome score (Knee Society score) and radiographs. Kaplan-Meier survival analysis was performed.
Results
There were no statistically significant differences in patient demographics at baseline between the MG UKA and AMK TKA groups (age 67.277.12 vs. 67.33 6.64, BMI 26.733.98 vs 28.526.00 respectively). There were 53 males and 34 females in both groups. In the MG UKA group, 29 patients were deceased (36 knees) and 17 knees were revised. In the AMK TKA group, 15 patients were deceased (19 knees) and 21 were revised. When revisions for infections were excluded, the 20 year survivorship for the MG UKA group was 80.9% and for the AMK TKA group was 78.5%.
The MG UKA group had better preoperative KSCRS scores compared to the AMK TKA group (102.9 24.3 vs 92.94 20.60, p<0.05), however both groups had a comparable change in KSCRS postoperatively. Similarly the MG UKA group had better preoperative knee flexion(120.949.71 vs 115.5914.35, p<0.05), although the UKA group on average demonstrated an improvement in knee flexion postoperatively (3.71(−35 to 45))whereas the AMK TKA group had a deficit (−4.95(−35 to 50) (p<0.05).
Conclusion
This retrospective evaluation demonstrates that the functional results of the MG UKA are comparable to the results obtained with the AMK TKA. There was a statistical difference in the change in knee flexion between the UKA and TKA, however there was no significant difference in the overall KCRCS scores. This indicates that functionally the UKA can be as successful as TKA for the treatment of osteoarthritis of the knee.
