dear patient osteoarthritis is a degenerative condition of the joints mainly affecting the knee hip and thumb base joint, its secondary if its after trauma, and primary if without trauma, here the cartilage of the joint gets gradually eroded, and multiple unknown factors are responsible for this, in these cases, you should maintain an active life with regular physio, to maintain your muscles, which will reduce the load on the joints, thus helping you gain more strength and less joint pain, the final solution if the physio does not work is replacement surgery. Thanks