Are knee replacements and shoulder replacements, a result of injury or just old

I have known several people (hubby included) who have had hip replacements. I also know folks who have had knee replacements. Most of these people the need for the replacment was arthritic changes in the joint. Injury is another cause for joint replacements, but I honestly feel that aging is the biggest factor and rheumatoid arthritis. (which isn't just age...)

I think it is a combination of both old age AND injury. I work in a nursing home, and we get people of all ages in for rehab. I also know 2 girls of around 50 years that had hip replacements and they had no more pain after their surgeries. I would recommend this surgery, if you needed it!

I think they can be both. My father had a knee replaced and I feel I need to have both knees replaced. I've had osteoarthritis in one knee for about 30 years and in the last couple of years, they both have deteriorated quite a bit. They are no longer straight, and I have more trouble walking now than ever before. I'd like 2 new knees please, but first I'll have to lose some weight.

Knee replacements are a result of both injury or age. I would definitely get a replacement anything if I needed it and it was available.