The ankle prosthesis
What is an ankle prosthesis?
The replacement of the ankle by a prosthesis is an operation by which the damaged ankle joint is replaced by artificial parts. It is made necessary in several situations, the most frequent being osteoarthritis, or abnormal wear, of the articular surfaces forming the ankle joint.
Until a few years ago, the only solution in the event of severe osteoarthritis of the ankle was arthrodesis, or blockage between the tibia and the rest of the foot. This operation relieved the pain quite effectively, but sacrificed the mobility of the ankle. This technique is gradually being replaced by the prosthesis, which also offers good pain relief while maintaining mobility.
Above, the ankle is formed above by the tibia and the fibula, which form a kind of mortise, and the astragalus below, which corresponds to a pulley. The joint space is wide, clearly visible .
Above, an X-ray of the left ankle with severe osteoarthritis: there is no more joint space, the surfaces are “worn”. This situation causes severe pain, and severely limits the ability to walk.
The prosthesis consists of 3 pieces: a tibial piece that replaces the lower surface of the tibia, a piece that replaces the upper surface of the astragalus (root bone of the foot), and an intermediate plastic piece, as shown below.
Model "Salto Talaris"
Result on an x-ray:
PREPARATION FOR THE OPERATION
Operability
Your family doctor, or any other doctor of your choice, will be asked to make a report on your current state of health and your history, to be passed on to our anesthesia department. This will allow the anesthesiologists to assess the operative risk, and to make an informed choice of the most appropriate technique for your personal case.
Medications
In order to reduce bleeding during the operation, certain medications, in particular anti-inflammatories, must be stopped some time before the intervention: Aspirin, Voltaren, Ponstan, Olfen, Brufen, Tilur, must be stopped 10 days before the intervention , Vioxx and Celebrex can be taken up to 48 hours before.
Physiotherapy
A few physiotherapy sessions may be prescribed just before the operation, in order to better prepare your muscles and familiarize you with the use of canes and the correct movements. This contact with the same physiotherapists who will follow you during your stay in the clinic will facilitate postoperative rehabilitation.
Entry into the clinic and preparation
You will enter the clinic the day before the procedure, usually in the afternoon. The anesthesiologist will visit you and together you will decide on the appropriate anesthetic technique. You may be given a light sedative the night before the operation, as well as just before it, but only if necessary and with your agreement.
Anesthesia
The operation can be performed under general or loco-regional anesthesia (epidural, spinal, etc.). The advantages and disadvantages of the various techniques will be discussed with the anesthetist during the preoperative visit.
DURING THE OPERATION
The procedure takes place in a supine position. The incision is made on the front of the ankle, lengthwise.
The procedure itself takes approximately 2 hours.
AFTER THE OPERATION
You will spend a few hours, possibly overnight, in the recovery room or intensive care unit for postoperative monitoring. The operated ankle will be immobilized in a first thick and comfortable cast, and the foot of the bed will be slightly raised. Just after the operation, one or two drains are left in place, small flexible pipes allowing the excess bleeding to be evacuated and thus to avoid the formation of a hematoma. These drains will be removed in the room after two to three days. The first 2-3 days will be spent in strict bed, after which walking rehabilitation will begin.
Post-operative pain can be quite severe, so it must be reduced by different means. Partial anesthesia (epidural, or leg anesthesia) is left in place for the first 2-3 days after the operation.
After two or three days, the patient can get up with the physiotherapist; he can put his foot on the ground, protected by a removable splint, but without putting down the weight of the body (=partial load) for 6 weeks in all, which means walking with two canes at all times throughout this period.
POSTOPERATIVE FOLLOW-UP
The threads or staples are removed between 2 and 3 weeks after the operation, after removal of the circular cast, and replacement with a Velcro splint.
The actual rehabilitation then begins with a physiotherapist, on an outpatient basis. It will then be necessary to exercise in particular the dorsal flexion movements (upwards) of the foot, which are the most difficult to recover.
The evolution of the operated ankle is monitored by regular checks at the consultation, accompanied by X-rays, generally according to the following scheme: 6 weeks, 3 months, 1 year, 5 years and 10 years after the operation.
The canes can be gradually abandoned between 2 and 3 months after the operation.
In the longer term, care must be taken to prevent secondary infection of the prosthesis. This can happen any time bacteria are released into the bloodstream, such as during a dental procedure, examination, or surgery on the bladder or bowel. Always tell any doctor treating you that you have a hip prosthesis.
In airports, passing through certain metal detectors can trigger the alarm. A certificate in French and English will be given to you, attesting that you have a prosthesis.
After 3 to 6 months, the patient can resume an almost normal life. Some sports such as cycling, swimming, walking or skiing can be practiced.