Total Ankle Replacement (TAR) for Ankle Arthritis

By Gordon L. Bennett, MD
Thursday, August 30, 2018

Ankle arthritis is a fairly common condition that occurs when the articular cartilage on the tibia and/or talus bones wears away. It most commonly occurs as a result of trauma (fractures or sprains), primary degenerative arthritis, or from an inflammatory condition such as rheumatoid arthritis. Patients typically experience pain, loss of motion, swelling, deformity, and often walk with a limp. Patients may be unable to perform many activities, such as walking long distances, exercising, working, running, or even doing low impact activities. Start-up pain is common, and the symptoms can progress to pain at rest and while trying to sleep.

Ankle arthritis is typically diagnosed by a thorough history and physical examination, as well as weight-bearing radiographs of the ankle joint. Occasionally, an MRI scan or a CT scan is ordered.

Treatment options can be non-operative or surgical. Non-operative management includes NSAIDs, ankle bracing, low impact activities, steroid injections, and gentle physical therapy. Surgical treatment depends on the severity of joint damage, the patient’s age, occupation, body habitus and activity level. Options can include arthroscopic surgery to debride or clean out the joint, ankle arthrodesis or fusion, and total ankle replacement (TAR).

TAR includes an artificial joint and resurfacing of both sides of the ankle joint in order to relieve the pain caused by arthritis and maintain range of motion of the ankle joint. The main goal of surgery is to relieve pain and allow patients to perform activities of daily living. The tibial side of the joint is typically replaced with a metal and polyethylene (plastic) component, and the talus bone is resurfaced with a metal component.

The best candidate for TAR is a healthy person who has minimal or no deformity of the ankle joint. TAR will usually function best in patients who are older, less active, and not overweight. TAR can wear out or loosen over time, and require a revision surgery or conversion to an ankle fusion. Patients who are younger and active, have significant deformity, prior history of infection of the ankle, dead bone in the ankle area, and severe neuropathy, should avoid TAR. Medical problems such as diabetes, poor circulation, skin ulcers, and heart and lung disease may put patients at a higher risk for infection and delayed healing of the surgical site. The main complications after TAR include infection, delayed wound healing, nerve and blood vessel injury, and loosening of the implants. Fortunately, these complications are not very common.

When performing TAR, orthopedic foot and ankle surgeons use a general or spinal anesthetic with a nerve block to decrease postoperative pain. The surgery is usually performed in the hospital, and patients typically stay in the hospital for one or two days. The incision is usually made on the front of the ankle joint. Special instruments and jigs that are frequently patient specific are used to make exact bone cuts on the tibia and the talus to allow for placement of the metal and plastic tibial component and the metal talus component. Occasionally, the Achilles tendon or calf muscle is lengthened at the time of surgery to improve motion and alignment.

Gordon L. Bennett, MD

After the surgery, patients are immobilized in an orthopedic splint for one week, and are then placed into a surgical boot. Protection and elevation is very important for the first few weeks. A period of non-weight bearing from two to six weeks in the boot is required, followed by four to six weeks of weight bearing in the boot. After the stitches are removed at about three weeks, gentle range-of-motion exercises are started. Formal physical therapy can start as early as six weeks postoperative.

Patients will typically improve for one year after surgery, but pain relief and an increase in activity usually occurs much earlier. The latest generation of TAR has had improved survivorship, and current research suggests that 70 to 80 percent of TARs are still functioning well after 10 years.

Dr. Gordon Bennett is an orthopedic foot and ankle surgeon and Director of Outpatient Surgery at Crystal Clinic Orthopaedic Center in Akron, OH. He is also Clinical Professor of Orthopedic Surgery at NEOMED.