Lateral UKA shows high survivorship at 10 years average follow-up
SAN FRANCISCO Using specific patient selection criteria and a well-defined surgical technique, performing lateral unicompartmental knee arthroplasty can produce success rates comparable to primary total knee arthroplasty through 10 years follow-up, according to a study presented here.
Sergio A. Romagnoli, MD, and colleague Francesco Verde, MD, both of the Instituto Orthopedico Galeazzi S.P.A., in Milano, Italy, reviewed the intermediate-term outcomes for unicompartmental knee arthroplasty (UKA) performed using the Allegretto UKA Prosthesis (Zimmer). They displayed their results in a poster at the American Academy of Orthopaedic Surgeons 75th Annual Meeting.
The study included 63 consecutive UKA procedures in 58 patients who averaged 69 years old at the time of surgery. All patients had lateral compartmental knee arthrosis, and all prosthesis components were implanted with cement, according to the study.
Eight patients (14%) died during follow-up from causes unrelated to the UKA surgery.
At 10.3 years mean follow-up, investigators found a 94.4% Kaplan-Meier survivorship, with only three knees (5%) revised due to instability.
Knee Society Scores improved from an average of 56 points preoperatively to 93 points at follow-up. Also, flexion improved from 108° preoperatively to 126°, according to the study.
"The study was optimized to strict patient inclusion criteria with attention to technique including component sizing and knee balancing. We limited the inclusion of patients with fixed flexion contractures of less than 10° and preoperative range-of-motion greater than 80°," the authors wrote.
"The inclusion criteria minimized the correction efforts and avoided significant lateral compartmental bone defects as well as insufficient ligaments and significant ligamentous releases," they noted.
"We recommend that following this specific selection criteria and surgical technique will allow for the achievement of similar results in the hands of other joint replacement surgeons," they wrote.
For more information:
- Romagnoli SA, Verde F. 10-year average follow-up of lateral unicompartmental knee arthroplasty with the Allegretto prosthesis. P205. Presented at the American Academy of Orthopaedic Surgeons 75th Annual Meeting. March 5-9, 2008. San Francisco.