ISAKOS: 2019 Congress in Cancun, Mexico
ISAKOS

2019 ISAKOS Biennial Congress ePoster #796

 

Knee Extra-Articular Tenodesis Has Minimal Effect on Tibiofemoral Contact Pressures

João V. Novaretti, MD, São Paulo, SP BRAZIL
Justin W. Arner, MD, Pittsburgh, PA UNITED STATES
Calvin K. Chan, MS, Pittsburgh, PA UNITED STATES
Sene Polamalu, BS, Pittsburgh, PA UNITED STATES
Christopher D. Harner, MD, Houston, TX UNITED STATES
Richard Debski, PhD, Pittsburgh, PA UNITED STATES
Bryson P. Lesniak, MD, Pittsburgh, PA UNITED STATES

University of Pittsburgh, Pittsburgh, PA, UNITED STATES

FDA Status Not Applicable

Summary

Lateral extra-articular tenodesis did not significantly increase contact pressures or area in the medial or lateral compartments, possibly indicating that the potential for osteoarthritis is not affected by the LET procedure. Further clinical studies are needed to evaluate the mid- and long-term outcomes of LET for knee rotational instability.

Abstract

Introduction

Supplementation of anterior cruciate ligament (ACL) reconstruction with lateral extra-articular tenodesis (LET) has become prevalent with the recent interest in the anterolateral knee capsule (ALC). However, some believe tibiofemoral joint contact pressures may be increased, which may amplify the risk of osteoarthritis. The purpose of this study was to quantify cartilage contact pressure and area after LET reconstruction.

Methods

Nine fresh-frozen cadaveric knees (mean age=66.4) were tested using a 6-degree-of-freedom robot. Two loading conditions with 200-N of compression were applied for each knee state at 30, 60, and 90 degrees: 134-N anterior tibial load and 7-Nm internal tibial rotation. After the intact knee was tested, a 2cm strip of capsule was removed to simulate anterolateral capsule (ALC) deficiency as previously described. LET was then performed using a semitendinosus graft. Tekscan pressure sensors were inserted to measure tibiofemoral medial and lateral contact pressures and area for each knee state. An ANOVA with post-hoc Bonferroni test was performed to analyze the variations of the medial and lateral compartment mean contact area and pressure at full-extension, 30º, 60º, and 90º of knee flexion. Significance was set at p <0.05.

Results

With anterior and axial loads at 90º, LET significantly reduced mean contact area in the medial compartment by 33.1% compared to the intact knee (p <0.05). With internal tibial rotation and axial compression at 30º, LET reduced mean contact pressure in the lateral compartment by 13.6% compared to the intact knee (p <0.05). No other significant changes in medial or lateral contact pressure or area were observed at other knee flexion angles when comparing LET to the intact and ALC deficient states.

Conclusion

LET did not significantly increase contact pressures or area in the medial or lateral compartments, possibly indicating that the potential for osteoarthritis is not affected by the LET procedure. Further clinical studies are needed to evaluate the mid- and long-term outcomes of LET for knee rotational instability.