Preliminary comparison of the rupture of human and rabbit anterior cruciate ligaments

Abstract

Objective. This study was aimed at examining ruptures of the human anterior cruciate ligaments by scanning electron microscopy and video imaging and comparing the appearance of the rupture surfaces with those from rabbit anterior cruciate ligaments. Design. The specimens were tested to failure as femur-anterior cruciate ligament–tibia complexes using an Instron 8511 materials testing machine. Background. Rupture of the anterior cruciate ligament is a major clinical problem, leading to instability of the knee joint. Due to the frequency and potential severity of the injuries, a need still exists for information on the biomechanical properties of ligaments under loading conditions, which occur at the time of trauma. Methods. Four human femur-anterior cruciate ligament–tibia complexes were loaded to failure at a displacement rate of 0.008 m/s. Video recordings of the tests were used to study the progress of the ruptures and to compare the modes of failure of the ligaments. Scanning electron microscopy was employed to study the appearance of collagen fibres at the rupture surfaces. Results. The modes of failure of the rabbit anterior cruciate ligament and appearance of the rupture surfaces were similar to those of the human anterior cruciate ligaments. Conclusion. The rabbit anterior cruciate ligament provides a model for investigating failure of the human ligament during trauma. Relevance The results will be of significance since most studies on ligaments are carried out on animal models with the intention of applying the deductions from the results to human ligaments. Examining the appearance of collagen fibres at these surfaces may help us to understand more about what actually happens during and after ligament rupture.