2023 ISAKOS Biennial Congress ePoster
Biomechanical Comparison Between Oval-Tunnel and Round-Tunnel for Anterior Crucial Ligament Reconstruction in a Porcine Model
Yong-Beom Park, MD, PhD, Gwangmyeong-Si, Gyeonggi-Do KOREA, REPUBLIC OF
Seong-Hwan Kim, MD,Ph.D, MStat, Seoul KOREA, REPUBLIC OF
Kyu-Tae Kang, MD, Seoul KOREA, REPUBLIC OF
Young-Bong Ko, MD, Seoul KOREA, REPUBLIC OF
Hyun-Chul Nam, MD, Seoul KOREA, REPUBLIC OF
Dong-Hoon Lee, MD, Seoul KOREA, REPUBLIC OF
Chung-Ang University , Seoul, KOREA, REPUBLIC OF
FDA Status Not Applicable
Summary
Oval tunnel anatomic single-bundle ACL reconstruction would be better in terms of rotational stability.
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Abstract
Purpose
The anterior cruciate ligament (ACL) reconstruction has been changed from isometric placement to anatomical position for restoration of normal kinematics and prevention rotational laxity. Recent cadaveric study reported that femoral footprint of the ACL was flat, ribbon like appearance, and tibial footprint of the ACL also was not round but oval or C-shaped appearance. A biomechanical study reported that rectangular femoral ACL fixation constructs and grafts was more efficacious at restoring ACL kinematics than round femoral tunnels. However, there were also studies that reported complication, such as fracture, incorrect alignment of long axis of footprint. Thus, the purpose of this study is to compare the laxity of porcine knee between conventional round tunnel and oval tunnel, which had similar philosophy of rectangular dilator in anatomical anterior cruciate ligament (ACL) reconstruction.
Methods
This was a biomechanical study for laxity using the porcine knees. Twenty porcine knees were used for the evaluation of the laxity following reconstruction techniques on the Instron instruments: conventional round tunnel technique (n=10) (Fig 1) and oval tunnel technique (n=10). (Fig 2) The porcine knee kinematics under simulated Lachman (89 N anterior tibial load) at 15°, 30° and 60° of flexion and a simulated pivot shift test (89 N anterior tibial load, 10 N/m valgus and 4 N/m internal tibial torque) at 30° of flexion were determined. (Fig 3) Kinematics were recorded for intact (n=10), ACL-deficient (n=10), and conventional round tunnel or oval tunnel technique. All measurements were repeated twice and the average was used for comparison.
Results
Under the Lachman test, conventional round tunnel and oval tunnel both showed significantly increased anterior tibial translation (ATT) at 30° and 60° when compared to the intact knee, (p<0.05) but decreased from the ACL deficient knees. (p<0.05) However, there were no differences of ATT between conventional round tunnel and oval tunnel technique. (round vs oval : 15°, 4.1mm ± 1.3 vs 3.9mm ± 0.6; 30°, 4.1mm±1.6 vs 4.2mm ± 1.3; 60°, 3.5mm±1.1 vs 4.5mm± 1.6; all p>0.05) Under simulated pivot shift at 30° flexion, there was significant difference between conventional round tunnel and oval tunnel technique. (round vs oval : 3.5mm ± 0.5 vs 4.3mm ± 0.8, p=0.028)
Conclusions
Although significant differences of ATT from the intact knee regardless ACL reconstruction technique were found, conventional round tunnel or oval technique both could decrease ATT when compared with ACL deficient knees. There were no significant differences between groups in the Lachman simulation, but the oval tunnel showed significantly better stability in pivot shift simulation at 30° than that of the round tunnel technique.