About five years ago I broke both bones in the middle of my right leg. Because of other injuries it was unsafe to operate, so the leg was treated in a cast. My bones healed, but with a bit of a bow. The breaks did not involve a knee joint, but this is where the pain is now. Is this arthritis?

Post-traumatic arthritis is the type of arthritis that occurs after an injury such as yours. Broken bones, where the fracture lines extend into the joint surface, have a high probability of developing arthritis. A broken bone in the middle of your leg resulting in a bow, or angled deformity, can also cause post-traumatic arthritis through a different mechanism. The bowing changes the alignment of the limb, which will alter the leg-bearing stress that the knee joint can take. When this happens, your body weight is no longer evenly distributed across the cartilage surface of the knee joint. This causes more stress on one side of the joint, wearing down the cartilage and causing arthritis. Sometimes the ankle joint can compensate for a small amount of bowing. If the bowing is substantial, the alignment can be restored with surgery. Surgery can redistribute the body weight and correct the problem if performed in the early stages of arthritis.