Canine Stifle Biomechanics Associated With a Novel Extracapsular Articulating Implant Predicted Using a Computer Model

OBJECTIVE: To evaluate the influence of the Simitri Stable in Stride™ extracapsular articulating implant (EAI) on canine stifle biomechanics in the cranial cruciate ligament (CrCL)‐deficient stifle using a 3‐dimensional (3D) quasi‐static rigid body canine pelvic limb computer model simulating the stance phase of gait. STUDY DESIGN: Computer simulations. ANIMALS: Five‐year‐old neutered male golden retriever (33 kg). METHODS: The EAI was implemented in a previously developed 3D CrCL‐deficient canine pelvic limb computer simulation model. Ligament loads, relative tibial translation, and relative tibial rotation were determined and compared to the CrCL‐intact and CrCL‐deficient stifle. RESULTS: The EAI significantly increased peak caudal cruciate and medial collateral ligament loads, significantly changed when peak lateral collateral ligament load occurred, and did not significantly affect peak patellar ligament load compared to the CrCL‐intact stifle. Compared to the CrCL‐deficient stifle, peak caudal cruciate, lateral collateral, and medial collateral ligament loads significantly decreased in the EAI‐managed stifle. Despite decreased peak caudal cruciate ligament loading, the EAI‐managed stifle generated local maxima that exceeded those of the CrCL‐deficient stifle at various intervals of stance. Peak relative tibial translation and rotation significantly decreased in the EAI‐managed stifle compared to the CrCL‐deficient stifle. CONCLUSION: Model‐predicted stifle biomechanics differed after EAI system application in the CrCL‐deficient stifle, but were not restored to that of the CrCL‐intact stifle.