Biomechanical properties of an implant designed to stabilize the coxofemoral joint following luxation show dissimilarity to the native ligament of the head of the femur in cattle.

Abstract

OBJECTIVE: To improve upon the toggle-pin implant construction and develop a repeatable surgical technique to achieve coxofemoral stabilization in mature cattle. ANIMALS: 9 adult bovine cadaveric coxofemoral joints, 8 bovine femurs, 2 beef calf cadavers. PROCEDURES: Ultimate tensile strength and elongation at failure were measured for the native ligament of the head of the femur (LOHOF) harvested up to 48 hours after death, and the prosthetic prototype utilizing stainless-steel cable and prosthetic prototype utilizing nylon leader line were compared. Bovine femurs were utilized to locate the ideal and repeatable trajectory of the prosthetic ligament to exit at the origin of the LOHOF. Using fluoroscopy, thawed calf cadavers with radiopaque markers placed at sites of origin and insertion of the LOHOF were positioned to assess limb angle to maximize joint isometry resulting in the ideal placement of the LOHOF prosthesis. The study was performed between February 1, 2020, and December 1, 2021. RESULTS: The stainless-steel prototype had a significantly higher ultimate tensile strength and significantly decreased elongation at failure when compared to the LOHOF, while the nylon-based prototype had significantly decreased tensile strength and elongation at failure compared to the LOHOF. Therefore, neither prototypes were biomechanically similar to LOHOF. CLINICAL RELEVANCE: The stainless-steel prosthetic prototype shows promise to provide superior stabilization to the luxated coxofemoral joint.