Ankle fusion is the surgical removal of the cartilage portion of the joint and diseased bone and fusing (growing) of the bones together into one unit. Good cartilage normally forms the joint and allows for essentially pain free motion between bones. Damaged or diseased cartilage can allow some motion but this motion can be quite painful and disabling. There are three different bones that have their cartilage removed. There is the talus which has a dome shaped top where the cartilage is removed. There is the tibia, the large long bone in your leg and the fibula the thinner long bone on the outside of you leg. Removing the cartilage exposes the underlying bone. This underlying bone can grow and fuse to other bone. The goal of ankle fusion is to eliminate painful joint motion by fusing the tibia bone to the talus bone the fibular bone may also be fused to the other bones.
Why is ankle fusion performed?
Ankle fusions are performed to eliminate pain, improve ambulation (walking), and to improve the quality of life. Typically conservative options are first attempted. These conservative treatments consist of treating the arthritis pain. Non-steroidal anti-inflammatory medications and analgesics are used. Corticosteroid infiltrations can be tried. Physiotherapy is attempted. Bracing with ankle braces or ankle foot type orthosis is used to try and immobilise the arthritic joint. Occasionally immobilisation in a cast or cam-walker cast is tried. Sometimes the ankle joint has arthroscopy (scope procedures) or arthrotomy (opening and cleaning) procedures are performed in an attempt to repair or remove arthritic joint cartilage or bone. If these treatments prove unsuccessful ankle fusion is performed.
What are some of the conditions that can damage the ankle and cause chronic pain?
Trauma including ankle fractures and crush injuries can lead to an arthritic joint. Chronic arthritis such as rheumatoid arthritis, severe osteoarthritis, gouty arthritis, traumatic arthritis and numerous other arthritic conditions can cause significant pain. Infection of the ankle joint may destroy the cartilage facilitating fusion. Failed ankle surgeries such as misaligned fracture surgery, failed ankle implants, failed arthroscopy and arthrotomy can all lead to fusion. There are also some congenital deformities that may need fusion and neuromuscular disease that create unstable painful ankle joints. Ankle joint instability after severe or chronic ligament tears may lead to chronic pain. Occasionally the bone in the ankle can lose its blood supply and die internally in a condition known as avascular necrosis this is usually secondary to trauma. A severe form of arthritic destruction known as Charcot arthropathy (joint disease) which is secondary to the nerve damage of neuropathy (nerve disease) can also be a causative condition.
How is ankle fusion performed?
Historically, there are many different ankle fusion procedures. Now most fusions fall into one of two general techniques. Ankle fusion can sometimes be performed by arthroscopic technique. This utilises small incisions to remove the ankle cartilage. The open technique has larger incisions on the outside and front of the ankle. To hold the bones together to immobilise them for healing various forms of internal surgical hardware is used. Bone screws, bone staples, bone plates and rods, and various other forms of immobilisation are used. External surgical fixation devices can also be used. Occasionally bone grafts are added if there is significant bone destruction or defects.
What usually happens after an ankle fusion?
Typically after surgery rest, ice and elevation are needed. Usually patients are not allowed to walk on the surgical site for two to three months. A non-weight bearing knee cast is typically applied. Occasionally it takes longer than three months. After this initial immobilisation a weight bearing cast may be applied and partial weight bearing is usually allowed and crutches or a walker are used to help with ambulation. Pain medications are used as needed. Slowly patients are re-introduced to full weight bearing ambulation. Physical therapy is often used. Complete recovery can take six to twelve months.