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This Article Full Text Full Text (PDF) All Versions of this Article: 36/6/1087    most recent 0363546508314433v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Request Reprints Google Scholar Articles by Mae, T. Articles by Fujie, H. PubMed PubMed Citation Articles by Mae, T. Articles by Fujie, H. Related Collections Reconstruction Biomechanics Graft fixation

Optimization of Graft Fixation at the Time of Anterior Cruciate Ligament Reconstruction

Part I: Effect of Initial Tension

Tatsuo Mae, MD, PhD^,*, Konsei Shino, MD, PhD, Ken Nakata, MD, PhD, Yukiyoshi Toritsuka, MD, PhD, Hidenori Otsubo, MD and Hiromichi Fujie, PhD^||

From the Department of Orthopaedic Surgery, Kansai Rosai Hospital, Hyogo, Japan, the Faculty of Comprehensive Rehabilitation, Osaka Prefecture University, Osaka, Japan, the Department of Orthopaedic Surgery, Osaka University Medical School, Osaka, Japan, and the ^|| Department of Mechanical Engineering, Kogakuin University, Tokyo, Japan

^* Address correspondence to Tatsuo Mae, MD, PhD, Department of Orthopaedic Surgery, Kansai Rosai Hospital, 3-1-69, Inabaso, Amagasaki, Hyogo, 660-8511, Japan (e-mail: ta-mae{at}umin.ac.jp).

Background: Although anterior cruciate ligament (ACL) reconstructions are frequently performed, little is known about the effect of initial tension on an ACL graft at the time of its fixation.

Purpose: The objective of this study was to evaluate the effects of initial tension on the relative position and the load between femur and tibia during passive motion.

Study Design: Controlled laboratory study.

Methods: Seven cadaveric knees underwent a passive flexion-extension movement from 0° to 90° with a robotic system developed in the authors’ laboratory under 6 degrees of freedom, while their 3-dimensional paths were recorded. A single-socket ACL reconstruction was performed with an autogenous quadrupled hamstring tendon graft, while the knees underwent the same movement as before with the initial graft tension of 22 N (group A), 44 N (group B), or 88 N (group C) at 20°. The relative position between the femur and the tibia was recorded, and the load in the femorotibial joint was calculated using the principle of superposition.

Results: The tibia in group C was most posteriorly positioned among the 3 groups (an average posterior translation of 0.6, 1.3, and 2.6 mm in groups A, B, and C, respectively). The tibia also moved proximally and laterally with external and valgus rotation with an increase in initial tension, and consequently the load in the femorotibial joint increased at all flexion angles.

Conclusion: With an increase in initial tension, the tibia moved posterolaterally with external and valgus rotation, and consequently the contact force in the femorotibial joint increased.

Clinical Relevance: Excessive initial tension at the time of ACL reconstruction may potentially bring deleterious effects to the articular surface, leading to cartilage degeneration.

Key Words: ACL reconstruction • initial graft tension • robotic system • tibia-femur position • load in the femorotibial joint