Acta Orthop Traumatol Turc
The effect of the tibial tunnel fixation level on the results of cyclic loading in anterior cruciate ligament reconstruction
Abstract
Objectives: This study was designed to compare the biomechanical characteristics of non-anatomic (far from joint) and anatomic (close to joint) levels of tibial tunnel fixation with soft tissue graft using a soft tissue interference screw in anterior cruciate ligament (ACL) reconstruction.
Methods: Twelve bovine tibiae and digital extensor tendons were divided into two homogeneously equal groups after removing soft tissues. Tibial tunnels were prepared with a 7-mm drill with the use of an ACL guide adjusted to 45°. Each tunnel was then dilated to 9 mm in 0.5 mm increments. Digital extensor tendons were fixed at non-anatomic (group I) or anatomic (group II) tibial tunnel levels with a soft tissue metal interference screw, 9x30 mm in size. All the specimens were cycled 500 times from 50 to 250 N with 1 Hz frequency in a servo-hydraulic testing machine followed by ultimate load at-failure testing at a rate of 20 mm/min. Statistical analyses were made using the Mann-Whitney U-test.
Results: The mean screw insertion torque values were 8.2±2.4 Nm and 7.8±2.3 Nm in groups I and II, respectively (p=0.88). The mean values of graft displacement (1.9±0.75 mm versus 2.2±1.2 mm, p=0.63) and stiffness (132.72±10.93 N/mm versus 125.14±15.93 N/mm, p=0.63) did not differ significantly, either.
Conclusion: The biomechanical properties of ACL reconstruction with soft tissue graft fixation using a soft tissue interference screw are not influenced by the level of tibial tunnel fixation.
Methods: Twelve bovine tibiae and digital extensor tendons were divided into two homogeneously equal groups after removing soft tissues. Tibial tunnels were prepared with a 7-mm drill with the use of an ACL guide adjusted to 45°. Each tunnel was then dilated to 9 mm in 0.5 mm increments. Digital extensor tendons were fixed at non-anatomic (group I) or anatomic (group II) tibial tunnel levels with a soft tissue metal interference screw, 9x30 mm in size. All the specimens were cycled 500 times from 50 to 250 N with 1 Hz frequency in a servo-hydraulic testing machine followed by ultimate load at-failure testing at a rate of 20 mm/min. Statistical analyses were made using the Mann-Whitney U-test.
Results: The mean screw insertion torque values were 8.2±2.4 Nm and 7.8±2.3 Nm in groups I and II, respectively (p=0.88). The mean values of graft displacement (1.9±0.75 mm versus 2.2±1.2 mm, p=0.63) and stiffness (132.72±10.93 N/mm versus 125.14±15.93 N/mm, p=0.63) did not differ significantly, either.
Conclusion: The biomechanical properties of ACL reconstruction with soft tissue graft fixation using a soft tissue interference screw are not influenced by the level of tibial tunnel fixation.
References
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