Surgical Overview
The ankle joint is made up of three bones: the lower end of the tibia (shin bone), the fibula (small bone of the lower leg), and the talus (bone that fits into the socket formed by the tibia and fibula). The ankle joint moves mainly in one direction like a hinge allowing your foot to move up and down. Inside the ankle joint the bones are covered with a thick, smooth material called articular cartilage. Articular cartilage allows the two bones to move/glide against one another and also helps distribute load across the entire joint surface, thus absorbing shock.
Osteoarthritis (OA) is a degenerative joint disease in which the articular cartilage (the tough but flexible tissue covering the ends of the bones) gradually wears away. In most cases, ankle osteoarthritis is related to a previous ankle injury and is termed, post-traumatic arthritis. X-rays help determine the severity of ankle damage. In a normal ankle, the articular cartilage creates the appearance of a symmetric joint space between the two bones making up the ankle joint (bottom left picture). As the articular cartilage wears away the joint space decreases progressing to bone on bone (bottom right picture).
Other imaging studies such as a CT scan or MRI also assist the physician in determining the amount of joint space narrowing, joint surface positioning and the overall degree of arthritic change to the ankle joint.
The main symptom usually associated with osteoarthritis in the ankle joint is pain. In the early stages of disease, pain is present with movement or activity (walking, stairs, prolonged standing). As osteoarthritis (OA) progresses, the pain can be present even at rest. Other common symptoms of ankle OA include; joint stiffness, loss of ankle motion, ankle joint swelling, and difficulty walking (or walking with a limp).
Treatment for ankle OA is focused on controlling pain, limiting motion that causes pain, and assisting in increasing walking tolerance. Non-surgical treatment approaches are usually tried first. Non-surgical treatment options include: medications (nonsteroidal anti-inflammatory meds), custom foot orthotics, AFO (ankle-foot orthosis) or other ankle braces to decrease ankle motion, physical therapy, dietary supplements (glucosamine and chondroitin), CBD cream and steroid/PRP injections into the joint.
Once conservative treatment options have been exhausted or the degree of OA is very severe, surgical intervention is usually necessary. There are mainly three main surgical options to treat ankle OA. These are: ankle arthroscopy – usually an option for milder OA to “clean up” the joint; ankle arthrodesis (fusion) – the gold standard for pain relief due to ankle OA where the ankle is fused as one solid bone; and total ankle replacement (TAR) – where the ankle maintains some degree of its normal biomechanics and motion.
Total ankle replacements (TAR) are performed less frequently compared to total hip and knee replacements but they are showing excellent functional outcomes. There are several types on the market today with the goal of recreating the anatomy and biomechanics (flexion/extension movements) of the natural ankle joint. The tibial component is comprised of metal and plastic and the talar component just metal (picture below).
Total ankle replacement
The TAR gives an alternative choice to some individuals versus an ankle fusion. It provides a better functional outcome by maintaining some flexion/extension motion at the ankle although not returning the motion to normal prior to the arthritic changes. It can relieve pain from arthritis and because it retains some normal biomechanics of the ankle joint, it helps to avoid the development of osteoarthritis in other joints of the foot. If there is adjacent joint arthritis (arthritis in the other joints of the hindfoot) then a total ankle replacement is an ideal option.
Total ankle replacements are fairly new and data continues to be collected on the overall outcome of this device over a prolonged period of time. The implant survival is approximately 10 years and after this time a revision may be necessary. Due to the extreme forces placed on the ankle Dr. Hofmann uses a rather strict criteria for who is the ideal candidate for a TAR. The following are the criteria for the IDEAL TAR patient: over the age of 40 years old; close to ideal body weight; does not perform strenuous physical exercise or work activity (running or construction-type work); has excellent circulation; has excellent medical health (no diabetes); and has good bone quality and minimal joint deformity. Certain exceptions are possible.
Your surgery generally takes place at the New England Baptist Hospital with overnight admission.
The procedure generally takes about 2-3 hours.
General anesthesia is usually used, but occasionally spinal anesthesia will be recommended by the anesthesia team. Most patients will have a preoperative anesthetic popliteal block performed to the back of the knee immediately before the surgery. This will decrease intra-operative anesthesia requirements as well as post-operative pain medication requirements. It is very effective in greatly reducing pain.
Benefits of a TAR include decreased pain, improved function and maintenance of ankle joint motion.
Ankle fusion or conservative treatments including long-term bracing.
Walking, biking, swimming, golfing, general mild exercise at the gym
Like any surgery, complications can develop. Fortunately, they are rare for most patients, but not zero. These include infection, bleeding, numbness, blood clots, delayed wound healing, bone fracture, prosthetic loosening or chronic pain and swelling. Appropriate recognition and medical treatment of these complications generally will allow for a satisfactory outcome. If a total ankle replacement must be removed for infection or failure, an ankle fusion can be performed or an antibiotic spacer can be placed until the infection is cleared and then revision TAR can be performed.
Once the rehabilitation process is complete, it is recommended to wear supportive shoes. Wearing supportive shoes is recommended as a life-long activity, however, after 1 year, more dressy shoes can be worn on special occasions.
You will get a dose of antibiotics before surgery and generally for 24 hours after surgery. Also, due to a length of time being immobilized, patients are started on one 325 mg aspirin once a day for 4 weeks.
Read carefully the “What to Expect and How to Prepare for Surgery” handouts.
No. Bleeding is minimal with use of a tourniquet during the surgery.
Discuss the surgery with your rheumatologist, but it is generally recommended that immunosuppressive modulator medications (eg. Methotrexate, Enbrel, Humira) are stopped for 2 weeks before and 2 weeks after surgery.
The foot is placed in a bulky cotton and plaster splint immediately after surgery. Recovery occurs in the Post Anesthesia Care Unit or PACU, and then you are admitted to the hospital floor. The nursing staff monitors your recovery and administers medications. You may go home generally in 1 day after meeting the discharge criteria. Physical therapy will assist in proper use of crutches, walker or medical scooter. A physician assistant will evaluate your progress, write prescriptions for pain medications, and instructions on follow-up care and appointments.
Focus for the first 3 weeks post surgery is to rest, get plenty of sleep, eat well and drink plenty of water. Your body will have greater metabolic demands on it to heal. If you are a poor eater, I strongly recommend drinking one or two medical protein shakes per day for the week before surgery and for two weeks after. Keep your surgical foot elevated at the level of your heart when you are not getting up to eat or use the bathroom. You should take the pain medication as directed as necessary. You should take the medication for reducing the chance of blood clots as well. Keep the splint clean and dry and do not walk on the splint.
Small spots may appear on the bandage. You may reinforce the dressing with an ace wrap obtained from a pharmacy. While highly unlikely, excessive bleeding through the bandage is of concern and you should call the office to be seen.
If the surgery was on the LEFT side, many patients drive by two weeks when they are off the pain medication. If surgery was on the RIGHT side, driving can resume at the six-week mark, at which time the walker boot can be removed to drive and then placed back on when getting out of the car. You will also be given a handicap parking placard as necessary.
That depends on what you do. Sedentary desk workers may return as soon as 3 weeks. On the other end of the spectrum, other professions that are a bit more demanding are typically out of work for 3-6 months. You will be provided out of work notes or restricted duty notes as necessary during the recovery phase. Family leave paperwork can also be submitted.
Download the TAR Post Surgical Guidelines PDF for full details.
