Background and Aim: Osteoarthritis is a common consequence of cranial cruciate ligament rupture (CCLR) in the canine stifle. Total knee replacement is a valuable method for managing end-stage osteoarthritis.

Materials and Methods: Two new designs of total knee replacement implants were fabricated with information from computed tomography scans. Canine hind limbs of cadavers were tested with a biomechanical testing machine with C-arm fluoroscopy. The four groups tested were as follows: Intact stifles (INTACT), CCLR, total knee arthroplasty (TKA) with a peg on top of the tibial component (TKAP), and TKA with no peg on top of the tibial component (TKAN). Extension, flexion, adduction, abduction, internal rotation, external rotation, cranial translation, caudal translation, and range of motion were measured.

Results: The cranial translation of the tibia relative to the femur increased significantly after cutting off the cranial cruciate ligament. After arthroplasty, adduction/abduction and cranial/caudal translation within the TKAN group was increased compared with the intact stifle group. In the TKAP group, only adduction was greater than it was in the intact stifle group.

Conclusion: The design of the prosthesis used for the TKAP group was more appropriate for total knee replacement in dogs than the design of the prosthesis for the TKAN group.

Keywords: cranial cruciate ligament, dogs, osteoarthritis, total knee arthroplasty.