Ankle Replacement Surgery
An ankle replacement surgery is where the joints of the ankle are fitted with a prosthesis or an implant to replace the existing worn out joints. It is usually recommended for the elderly and relatively inactive person as one of the major complication from such a surgery is loosening of the ankle joint due to overuse. After the surgery, you will be placed on a cast to protect the joint for a period of 6-12 weeks before you can gradually put weight on it. An ankle replacement can generally last 5 – 10 years depending on the activity level of the patient.
Who will need such a surgery?
An ankle replacement surgery is usually recommended for people with a degenerated or arthritic ankle joint that causes them pain and difficulty in moving the ankle or walking. In a degenerated or arthritic joint, the articulating surfaces are not smooth as compared to a normal joint with cartilages that allow for smooth gliding of joint surfaces over each other. The lack of smooth articulating surfaces in a degenerated or arthritic ankle can be due to either wearing away of cartilages or due to osteophytes (also known as bone spurs). This can cause pain in the ankle especially during movements of the ankle joint and on weight bearing activities like walking. With an ankle replacement surgery, an implant can be fitted into the degenerated or arthritic ankle to allow for smooth gliding of the joint surfaces, permitting pain-free movements to take place.
What happens during the surgery?
During the operation, your surgeon will shift the soft tissues like nerves, blood vessels and muscle tendons aside so that the surgeon have sufficient space to work on the ankle joint. The tibia and talus will be shaved and resurfaced to accommodate the ankle implants or prosthesis. The ankle prosthesis consists of the tibial component which is fitted into the end of the tibia; and the talar component which is fitted on top of the talus. The fibula and tibia will be screwed together tightly to ensure that the tibial component is fitted tightly. The fibula and tibia will also be fused together by bone graft or bone cement so that the artificial ankle can move up (dorsiflexion) and down (plantarflexion) without damaging the surrounding structures.
What happens after the operation?
After the surgery, you will wake up with your leg in a cast or a splint. A tube may be attached to the ankle to drain off excessive bleeding. You will be taught to walk using crutches without putting weight on the operated foot. Your ankle will also be immobilized in a cast or ankle splint to protect the artificial joint for a period of 6 -12 weeks depending on your surgeon. One of the major complications that may arise from the operation is the loosening of the prosthesis. A typical ankle replacement may last for 5 -10 years depending on the activity level of the patient. In fact, research has shown that the artificial ankle joint has a better lifespan in an older patient than in young active patients. One of the reason is that younger patients tend to be more active than sedentary older patients and hence a higher risk of loosening the joint. In such cases, an ankle fusion may be a better alternative for this group of young patients with heavy and prolong activity requirements. Regular X-rays will be taken after the ankle replacement surgery to ensure that the implant has not moved out of place. Gradually your physiotherapist will improve on your rehabilitation exercises and introduce weight bearing activities on your ankle again.
- Wood and Deakin (2003), Total ankle replacement – The results in 200 ankles. J Bone Joint Surg 2003;85-B: 334-41.