Intraoperative Analysis of Knee Kinematics During ACL Reconstruction - an Exploratory Study

Anterior cruciate ligament reconstruction is a common procedure in orthopaedic surgery, aimed at restoring knee stability following a ligament rupture. Despite technological advances and improvements in surgical techniques, failure rates remain a cause for concern. There are many causes of ligament reconstruction failure, including biological factors (e.g. poor graft integration), repeated trauma and technical errors. Among the latter, poor tunnel positioning is the main cause, accounting for up to 29% of errors, the majority of which (75%) involve the femoral tunnel. Biomechanical studies have confirmed that inadequate positioning of the femoral tunnel alters knee kinematics, increasing stress on the graft and predisposing it to secondary rupture. In this context, a better understanding of intra-articular knee movements and the tension/relaxation profiles of the knee ligaments during flexion movements in surgery could improve the accuracy of reconstructions and reduce the long-term failure rate. Using a surgical navigation system, it is possible to record data on the dynamic positioning of the femur and tibia during flexion and extension. MRI imaging also makes it possible to generate a digital twin of the patient's knee, including the patient's ligaments and their bony attachments. Aligning this digital twin with the positions of the femur and tibia recorded using intraoperative navigation makes it possible to determine, at different angles of flexion, the position of the digital twin and thus to measure the distance between the ligament insertions in the knee. This type of morpho-functional analysis of the 3D kinematics of the knee has not been published. This is why this research is initiated.