Ankle arthrodesis is a type of surgery where the joint between the tibia and fibula bones of the lower leg, and the talus bone of the ankle, is fused together. This type of ankle surgery is usually carried out as a treatment for severe ankle pain, typically caused by arthritis. It is normally reserved for patients who have tried non-surgical remedies, such as specially modified shoes and pain-killing drugs, but without success. Ankle joint fusion is generally used in younger, more active patients as an alternative to having an artificial ankle replacement, because a fused joint is more durable and does not wear out.
An ankle arthrodesis procedure involves fixing together the talus bone of the ankle and the ends of the tibia and fibula bones in the lower leg. After the surfaces of the bones have been leveled off to remove damaged bone and cartilage, metal screws are used to hold them together. As part of the healing process, the development of new bone unites the cut surfaces and fuses the joint. The ankle joint then becomes rigid, but the flexibility of the foot and the knee helps compensate for this, and the person is often able to walk normally, although running may not be possible. Following arthrodesis surgery, it normally takes around three months before fusion is complete, so the joint will need to be rested and a cast may be worn during that time.
Keyhole surgery may be used to carry out an ankle arthrodesis, and this has the advantage that recovery is faster, and there is less pain after the operation than with traditional open surgery methods. In a keyhole surgery technique known as arthroscopy, small cuts are made in the skin of the ankle in order to insert a viewing instrument into the joint, together with miniature surgical tools. Patients are normally able to place weight on the joint the day after surgery, using a supportive cast or crutches, and to begin physiotherapy. Open surgery may be used for more complicated cases, perhaps where a deformity needs to be corrected in addition to joint fusion, and sometimes an external metal frame is fastened around the leg to fix the bones in place, instead of placing screws inside the joint.
One possible disadvantage of ankle arthrodesis is that extra strain is placed on other joints around the fused ankle, which may cause them to become arthritic over time. For a person with arthritis in two ankles, it could be very disabling if both are fused, as some degree of ankle flexibility is needed to get up out of a chair. In this case, a joint replacement might be used in one ankle. For less active or older people, who are unlikely to wear out a prosthesis, ankle mobility may be more important than joint stability, and a prosthetic ankle replacement may be a better choice than ankle arthrodesis.