Are There Alternatives To Total Knee Replacement For Restoring Function While Having Severe Cartilage Loss And Knee Instability In A Polio Survivor?

Hi, I am a 63 year old polio survivor and got polio in my left leg. About 5 years ago I took a fall and ruptured my knee which damaged the cartilage on one side of my knee. My knee healed but it is not the same. I could run before but now I cannot due to the instability in my knee. Since the accident I have managed a degree of mobility using knee braces but I have to watch every step. I did see an orthopedic doctor, had my knee scanned, and it appears I that I am bone to bone on the outside of my knee. the doctor recommended a total knee replacement and also said I could try injections. I have been hesitant because I am not sure if my leg can sustain/recover from it. The polio affected leg is much smaller and weaker that my right leg. What is your opinion? Is there a way to add/repair the cartilage in my knee without total knee replacement?