Article

The use of an offset type tensor for total knee arthroplasty that can
be set with patellofemoral joint reduction and femoral component placement
enables surgeons to assess soft tissues in the physiological postoperative knee
condition, showing different kinematic pattern of soft tissues in varus
osteoarthritic knees between cruciate-retaining and posterior-stabilized total
knee arthroplasty. However, gap kinematics in unicompartmental knee arthroplasty
is unclear. METHODS: Using a newly developed tensor that is designed to assess
soft tissue balance throughout the full range of motion with femoral component
placement, we assessed the intra-operative joint gap measurements of
unicompartmental knee arthroplasties performed at 0, 10, 30, 45, 60, 90, 120 and
135 degrees of flexion in 20 osteoarthritic patients. In addition, the kinematic
pattern of unicompartmental knee arthroplasty was compared with those of
cruciate-retaining and posterior-stabilized total knee arthroplasty that were
calculated as medial compartment gap from the previous series of this study.
FINDINGS: While the joint gap measurements of unicompartmental knee
arthroplasties increased from full extension to extension (10 degrees of
flexion), these values remained constant throughout the full range of motion. Of
note, the gap values of cruciate-retaining total knee arthroplasty were
significantly smaller from midrange to deep flexion compared with
posterior-stabilized total knee arthroplasty, and furthermore unicompartmental
knee arthroplasty showed a significantly smaller gap from extension to midrange
flexion compared with cruciate-retaining total knee arthroplasty. INTERPRETATION:
Accordingly, we conclude that the intra-operative joint gap kinematic pattern in
unicompartmental knee arthroplasty differs from the pattern in total knee
arthroplasty.
CI - Copyright (c) 2012 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS