This report describes the surgical technique, instrumentation and results of complete substitution of portion distal of the femur and knee articulation to prosthesis, in a dog with bone tumor in distal left femur. The prosthesis was made of steel, and composed by three articulated components with the goal of maintaining range of motion as a normal knee movement. The femoral and tibial prosthesis portions were fixed to the respective bones during the surgery, after femural and tibial plato ostectomy. The patient received six doses of adjuvant chemotherapy, composed by doxorrubicin monthly alternated with carboplatin. At six days after surgery the dog developed neuropraxy and non-weight bearing lameness. At 10 days the dog started to mild use of the limb and at 30 days it was more effective, but the extension of the stifle range was reduced by 100° because of the fibrosis and muscle contracture on the popliteal fossa. At one year, this angle didn't improve but the dog continued to bear weight on the limb. At 425 days, the dog had died by renal failure. At this time, there was no evidence of local recurrence or distant metastasis, but the necropsy was declined by the owner, impairing the collection of more data. In conclusion, the replacement of total knee and half of the femur in dogs is possible and viable, but further study is warranted in order to obtain better technique and specific instrumentation, to attain better surgical outcomes.
dog; knee; osteosarcoma; prosthesis
