I have used homeopathy to help dogs with luxating patellas. Your results will depend upon whether there is a severe deformity. I would try PROMAXOL to reduce the pain and help healing to begin. PROMAXOL would be a good choice for your dog because it contains the LM potencies. After improvement is seen then you can switch over to ARTHRO-IONX. In addition it is helpful to give Probiotics with each meal, Omega 3,6,9, MSM, and vitamin C daily. (We carry the first two and the other two you can get at a health food store.) The oligotherapeutic mineral base found in the IONX products helps the body to better utilize the other nutritional substances given for a synergistic response and faster healing. Also be sure to give sufficient fresh water that is free of chlorine and fluoride. If you can gradually phase into a grain free diet that can be helpful too. The other thing that is with sometimes beneficial is to have a certified veterinary chiropractor check for spinal alignment and make any corrections as necessary. Tightening of the muscles can pull the bones out of alignment and put more stress on the knee.
Please let us know how you progress or if you have any other questions. I would try this approach before considering surgery.