Koko had to have both knees operated on for torn CCL's. She spent 6 weeks in her crate and then after her second surgery another 6 weeks. I had to carry her down about 10 steps from my porch so she could go out to do her business. She weighed around 90lb back then. Her Vet said her knees went out because of extra stress caused by hip dysphasia. She still has bad hips but we just exercise her a lot and she does great. Watching her run you would never know see had both knee surgeries. When the weather is rainy she suffers some so she gets regular doses of Glucosamine, Chondroitin and an anti-inflammatory drug.