Ankle replacement is designed to treat arthritis of the ankle. This type of arthritis is most commonly caused by osteoarthritis, rheumatoid arthritis or post-traumatic arthritis. Osteoarthritis is "wear and tear" of the cartilage in a joint. Rheumatoid arthritis is caused by a system-wide disease process, which affects the entire body. Osteoarthritis can affect isolated joints whereas rheumatoid arthritis usually affects multiple joints. Post-traumatic arthritis is the breakdown of cartilage which occurs after a joint has been injured, such as by a fracture. In a candidate for ankle replacement, the arthritis has typically progressed to a complete or near complete loss of cartilage on the surface of the ankle bones.
In a normal ankle joint, the surface of the bones touching each other have a smooth layer of cartilage covering them. We don't feel pain in a normal ankle when walking or standing, because the cartilage does not have nerves and we therefore do not feel sensation. When a joint has arthritis, the cartilage breaks down, becomes rough, and wears through to expose the bone underneath.
The pain that results is typically caused by the rough exposed bony surfaces rubbing against each other. The bone, unlike the cartilage, does cause us to feel pain when it is contacted. In addition to the pain from the bone, arthritis pain comes from swelling and stretching of the joint lining, called the synovium. Osteophytes, commonly known as "bone spurs", can also form and cause irritation and pain.
Mild, temporary pain can be treated at home with rest, ice, and over the counter arthritis medication. If you are having pain in the ankle that does not resolve or progressively gets worse you should consult a physician. Extreme pain, swelling, warmth or stiffness should also be evaluated by a doctor.
Ankle replacement surgery is designed to relieve pain and restore motion. Once fully recovered from the surgery, the pain should be dramatically improved compared to before the surgery. As with any joint replacement surgery, you may still have some occasional minor aches and pains around the ankle, usually associated with your level of activity.
A good candidate for ankle replacement surgery is someone over the age of 50 who does not smoke, is not overweight, and is in otherwise good health and not extremely active. Smoking can adversely affect the healing of the implant to bone and surgical incisions. Being overweight puts more stress on the ankle replacement parts and can increase the risk of poor healing and loosening of the replacement. Other medical problems such as diabetes, heart disease, lung problems, nerve conditions, and poor blood circulation increase the risk of complications and may preclude ankle replacement. The activities which are not ideal are those which involve repetitive pounding of the ankle; for example running or a job which includes heavy labor. Patients who have poor circulation in the leg, those who have diabetes, or who have certain nerve conditions of the leg are not good candidates for an ankle joint replacement. The bone quality of the ankle must be good; bone that is too soft or that is collapsing can cause the ankle implant to fail. Ultimately, the decision as to whether you are a good candidate for ankle replacement comes from evaluating all of these factors in consultation with your orthopedic surgeon.