Long-term outcome of an intra-articular allograft technique for treatment of spontaneous cranial cruciate ligament rupture in the dog

Objective: To determine the 12-month outcome in dogs with spontaneous cranial cruciate ligament (CCL) rupture after repair with an intra-articular decellularized allograft. Study Design: Prospective pilot case series. Animals: Ten client-owned dogs with unilateral CCL rupture. Methods: An intra-articular, decellularized, deep digital flexor tendon allograft was secured in the stifle with a femoral cross pin and tibial spiked washers and screws. An interference screw was placed in the tibial tunnel. Dogs were evaluated with an owner questionnaire, radiographs, and force platform gait analysis before and 2, 6, and 12 months after surgery. Results: Owners reported improvement in level of pain and mobility throughout the study, especially over the first 6 months. Peak vertical force and vertical impulse improved across all time points. Ground reaction force asymmetry index for peak vertical force and vertical impulse at 12 months showed 3 dogs within a normal index (<6%), 4 dogs as nonvisibly lame (6-20%), and 3 dogs as visibly lame (≥20%). For most dogs, osteoarthritis scoring did not change over the 12-month period and some femoral-tibial translation was detected on standing horizontal beam radiographs. Conclusion: Intra-articular repair using a decellularized allograft can provide functional clinical outcomes in dogs with CCL disease. A better understanding of long-term engraftment after this procedure is needed.