In a mobile-bearing unicondylar knee arthroplasty (UKA) stability is very important for the knee function and to prevent dislocation of the insert. A tension-guided technique to determine the position of the optimal posterior bone cut should theoretically lead to a better varus-valgus stability. The goal of this study was to measure the difference in valgus laxity in flexion and extension between a tension-guided and spacer-guided system for mobile-bearing UKA. Also clinical function was evaluated between the groups. A tension-guided UKA system (BalanSysTM, Mathys, Bettlach, Switzerland) was compared with a retrospective group of a spacer-guided system (Oxford, Biomet Ltd, Bridgend, UK). A total of 30 tension-guided UKAs were placed and compared to 35 spacer-guided prostheses. Valgus laxity was measured at least 6 months postoperatively in both groups using stress radiographs. The flexion stress radiographs were made fluoroscopically aided in 70 degrees of knee flexion. Laxity measurements in extension were performed on stress radiographs obtained with the Telos device. Knee Society Scores (KSS) were obtained at follow-up.Background
Patients and Methods
