Abstract
Background
One of advantages of single-radius femoral design was to offer better ligament stability based on a maintained isometry of extensor muslce during the whole range of motion. The purpose of this study was to compare intraoperative varus-valgus laxities from 0° to 90° of flexion in patients that received TKA using either a single-radius femoral design or multiradius femoral design.
Methods
56 TKAs with a single-radius femoral design (SR group) and 59 TKAs with multiradius femoral design (MR group) were included in this study. We measured and compared varus-valgus laxities at 0°, 30°, 60°, 90° of flexion using the navigation system and manual force between the 2 groups.
Results
The mean total varus-valgus laxities in both groups were significantly less at 0° of flexion(3.2 ± 1.5° in SR group and 3.5 ± 1.8° in MR group) than other selected flexion anlge (p=0.011); but the difference was not significant between 2 groups (p=0.062). At 30°, 60° of flexion, the mean total varus-valgus laxities in SR group (6.2 ± 3.5° at 30° of flexion and 6.8 ± 1.5° at 60° of flexion) were significant less than those in MR group (9.2 ± 4.3° at 30° of flexion and 8.3 ± 3.8° at 60° of flexion) (p=0.027 and p=0.042, respectively).
Conclusions
The single radius femoral designs showed significantly less intra-operative mid-flexion laxities compared with the multiradius femoral designs.
