Publication

The variation in medial and lateral collateral ligament strain and tibiofemoral forces following changes in the flexion and extension gaps in total knee replacement. A laboratory experiment using cadaver knees

Journal Paper/Review - Nov 1, 2007

Units
PubMed
Doi

Citation
Jeffcote B, Nicholls R, Schirm A, Kuster M. The variation in medial and lateral collateral ligament strain and tibiofemoral forces following changes in the flexion and extension gaps in total knee replacement. A laboratory experiment using cadaver knees. The Journal of bone and joint surgery. British volume 2007; 89:1528-33.
Type
Journal Paper/Review (English)
Journal
The Journal of bone and joint surgery. British volume 2007; 89
Publication Date
Nov 1, 2007
Issn Print
0301-620X
Pages
1528-33
Brief description/objective

Achieving deep flexion after total knee replacement remains a challenge. In this study we compared the soft-tissue tension and tibiofemoral force in a mobile-bearing posterior cruciate ligament-sacrificing total knee replacement, using equal flexion and extension gaps, and with the gaps increased by 2 mm each. The tests were conducted during passive movement in five cadaver knees, and measurements of strain were made simultaneously in the collateral ligaments. The tibiofemoral force was measured using a customised mini-force plate in the tibial tray. Measurements of collateral ligament strain were not very sensitive to changes in the gap ratio, but tibiofemoral force measurements were. Tibiofemoral force was decreased by a mean of 40% (SD 10.7) after 90 degrees of knee flexion when the flexion gap was increased by 2 mm. Increasing the extension gap by 2 mm affected the force only in full extension. Because increasing the range of flexion after total knee replacement beyond 110 degrees is a widely-held goal, small increases in the flexion gap warrant further investigation.