January - April 2008 Issue
Can Ankle Arthritis Be Treated?
Richard Marks, MD, FACSMedical College of Wisconsin Orthopaedic Surgeon
Director, Foot and Ankle Program
Ankle arthritis can be caused by several things, but the most frequent cause is trauma — a severe ankle sprain or fracture. While less common than hip or knee arthritis, ankle arthritis can also be treated by joint replacement. Dr. Richard Marks discusses ankle replacement, ankle fusion and other procedures to treat ankle arthritis.
Q. What is ankle arthritis?Arthritis is an inflammatory process due to the loss of the joint space. Cartilage lines the joint on either side of the bones and allows them to glide smoothly. When there is damage to the cartilage, the joint space diminishes, often with associated inflammation. The combination of inflammation and loss of joint space defines arthritis.
Ankle arthritis is less common than arthritis involving the hip or knee. In fact, arthritis of the hip and knee is nine times more common than ankle arthritis because of the unique nature of the cartilage of the ankle joint.
Q. What are the signs and symptoms?Patients with an arthritic ankle typically complain of painful, decreased motion of the ankle that may be worse when they attempt to walk, squat or go up and down stairs. There may also be swelling of the ankle joint and, typically on examination, there will be tenderness along the front part of the ankle joint, particularly with attempts at motion.
In more advanced cases, patients will complain not only of diminished motion and pain during walking, but also of rest pain and pain at night. In more advanced cases, pain may be persistent.
Q. What causes arthritis of the ankle?Most ankle arthritis occurs following trauma to the ankle, so patients who have suffered severe ankle sprains or fractures in the ankle or the talus (the bone that connects the leg to the foot) can develop post-traumatic arthritis. Other causes are due to normal degenerative changes (idiopathic arthritis) much like people experience in the hip or knee joint. Some patients may develop ankle arthritis because of an angular deformity of the tibia or the hindfoot. Patients with ligamentous laxity (loose ligaments), whether a result of injury or a developmental problem, may also develop arthritis. Patients with inflammatory arthritis, such as rheumatoid arthritis, or with a condition called avascular necrosis of the talus, in which the talus bone loses its underlying blood supply, may also develop ankle arthritis.
Q. How is ankle arthritis diagnosed?It’s diagnosed by obtaining a medical history and a description of symptoms, conducting a physical examination and taking X-rays. In more complex cases, we may need to get a bone scan, a CT scan or, rarely, an MRI scan.
Q. What are the treatment options?There are a variety of surgical and non-surgical treatment options. From a non-surgical standpoint, we would recommend the use of anti-inflammatory agents, steroid injections, bracing and shoe modifications. Different immobilization braces can help take weight off the ankle and provide less motion, so walking is less painful. Shoe modifications consist of a rocker-bottom sole, which takes stress off the ankle upon impact and also allows patients to roll forward on their foot as they walk.
Q. What are some of the surgical options?Surgical options vary depending on the type and extent of arthritic changes, the patient’s other medical problems and what they expect to be able to do after treatment. There are a variety of procedures that we may recommend depending on the patient’s symptoms, deformity and lifestyle.
In some more severe cases, we may consider an ankle fusion or an ankle replacement procedure. Ankle fusion reliably relieves pain from arthritis, but does diminish ankle motion by about 50 percent. It is much more commonly performed than ankle replacement because fewer people meet the criteria for ankle replacement. Therefore, fusion is really the gold standard.
However, as technology and instrumentation improve, and we understand the biomechanics of the ankle better, ankle replacement is now available to more patients. The newer total ankle designs that we’re presently using have a much better track record for pain relief, while maintaining motion and improving patient outcomes.
Both ankle fusion and ankle replacement are offered only after patients have failed other non-surgical options. It would be rare to proceed with a fusion or replacement if other treatments had not been tried first.
Q. What are the benefits and limitations of ankle fusion and ankle replacement?Fusion is a permanent procedure that won’t need to be revised in the future. Ankle replacement may need to be revised 10 to 12 years in the future, but this average varies due to activity levels of patients.
Fusion does diminish ankle motion, and theoretically, places added stress on adjacent joints. For people who want to maintain motion in the ankle joint, replacement provides more normal movement. Choosing which procedure is best is part of the shared decision-making process that takes into account the patient’s lifestyle and expectations.
A fusion is performed by scraping out the degenerated bone and cartilage between the tibia and talus bones and then fusing the two bones together, typically with the use of screws and/or plates. On occasion, a rod may be placed across the joint as well. A number of different techniques are used to fuse the bones together. The fusion procedure removes the arthritic cartilage and bone, thereby creating this rigid ankle joint. It also relieves pain.
The indications for a total ankle replacement are fairly narrow. We typically like patients to be at least 50 years old with a body mass index of less than 35, so they can’t be morbidly obese. Patients also cannot do repetitive loading activities, so this would not be a good procedure for runners or heavy laborers, for example.
Ankle replacement patients cannot have any extensive angular deformity, and they need to have an adequate amount of bone. Smokers and patients with diabetes mellitus, peripheral neuropathy (diminished sensation) or a history of ankle infection cannot undergo an ankle replacement.
Q. What are some of the other surgical procedures available?The choice of procedure depends on the patient’s condition and needs. One surgical option to treat ankle arthritis is ankle arthroscopy, which involves the debridement – or cleaning out – of the joint and removal of any overgrowth of bone in the front part of the joint.
A second option is called an anterior ankle arthroplasty, which is the removal of bone in the front of the joint through an open incision. In patients with angular deformity, we would make corrective cuts in the bone to straighten out the limb. This off-weights, or lessens stresses, on the arthritic portion of the joint. Other patients who have ligamentous laxity (loose ligaments) may require a ligament repair and stabilization.
For younger patients who have advanced arthritic changes and wish to avoid ankle fusion or ankle replacement, there is a technique called distraction arthroplasty. It consists of debriding, or cleaning out, the front part of the joint and applying a frame (an external fixator) that allows the ankle to be stretched apart, thereby off-weighting the arthritic cartilage. This less invasive procedure was popularized in Europe several years ago, and it has moderate results. While this procedure may not provide long-term relief, it allows us to proceed with either ankle fusion or ankle replacement in the future, if necessary.
Q. How do you decide whether to perform a fusion or a replacement procedure?If someone is considered a good candidate for either procedure, then we discuss the relative risks and benefits of both procedures. It’s a shared decision-making process during which we inform patients about the limitations of both procedures.
Both procedures provide good pain relief and good improvement in walking. This is something we’ve actually evaluated in our Gait Lab.
At Froedtert & the Medical College of Wisconsin, we have extensive expertise in performing different types of fusions and also in implanting the two FDA-approved replacement devices. We’re also actively involved in evaluating the gait of patients with ankle arthritis before and after treatment. No other facility in Wisconsin has the capabilities to evaluate patient outcomes like we do.
That allows us to more objectively and scientifically counsel patients as to which procedure might better suit them, and it allows them to better share in the decision-making process. We’re considered at the forefront of total ankle technology and expertise.
Source: Every Day
Date: Jan - April 2008 Issue