In Vivo Method for Tracking 3D Kinematics of the Healthy and Anterior Crucial Ligament Transected Goat Knee Joint: A Preliminary Study

The objective of this paper is to introduce a novel method for tracking 3D kinematics of the healthy and anterior crucial ligament (ACL) transected goat knee. Sham and ACL transection surgeries were performed on two goats (1 sham, 1 ACL transection) with tantalum bone markers inserted into the tibia and femur. Goat gait was captured using a high-speed, biplanar fluoroscopy system and bone markers were digitized to extract their 3D coordinates during the entire goat gait cycle. A method for defining a clinically relavent anatomical coordinate system was developed based bone features present on 3D bone models from computed tomography (CT) scans of the two goat knees. The defined anatomical coordinate system was linked, rotoscoped, and animated to extract meaningful rotational and translational gait kinematics. Rotational range of motion measurements were calculated with the largest range of motion in flexion/extension (FE), followed by internal/external (IE) rotation, and then ab/adduction (AB/ADD). The magnitude of anterior/posterior (AP) translation was determined showing slightly elevated translation in the ACL transected goat knee. These data indicate the ability to and repeatability of tracking 3D kinematics in vivo.