Ankle Replacement (Salto)

"I would like to thank you for the wonderful job done... a huge success. I walk my dogs over rough ground, climb up fairly steep slopes with little or no swelling. In short I am thrilled with the operation!".
LW

This operation is designed to remove the arthritic joint and the arthritic pain from it and retain movement within the joint. In the same way that a Knee and Hip replacement replace the arthritic joint with metal and specialised plastics, an ankle replacement does the same by replacing the arthritic surfaces of the joint with specially designed metal and plastic components. The metal is an ultra-highly polished steel with a titanium coating which bonds to the bones. The plastic is a high density polyethylene which is resistant to wear.

Once fully recovered, after a few months, you should be able to walk almost normally with minimal or no pain. The ankle will move much more than before, and the amount of movement will depend on how stiff it was prior to surgery. A patient with a successful ankle replacement will be able to resume normal walking activities such as hill walking, hiking and and golf. Also sports such as skiing, sailing, shooting and tennis are possible. High impact activities such as running and jumping cannot be expected.

Preparation for ankle replacement surgery.

• Prepare for the first 2 weeks of non-weight bearing - you should see a physiotherapist who will train you in the best techniques that suit your ability.
• There are some devices that can help with the early period where walking will be harder. Many patients like the Knee rover from www.kneerover.co.uk - a scooter that takes the weight of the leg. Or the iWalk device from www.peglegs.co.uk

• Prepare for the first 2 weeks of elevation - raise the foot of the bed 2-3 inches either with books under the legs or with pillows under the mattress. If possible plan layout of your home and which rooms will be used mainly (the bathroom, kitchen and bedroom) and if possible move beds etc to minimise difficulties.
• Avoid getting any cuts / scratches or infections in the leg as this will prevent surgery going ahead.
• If the ankles are very swollen use a compression stocking to minimise this.

Preparation for surgery

• No food, drink or smoking 6 hours before surgery - clear water can be taken up to 2 hours before.
• Take all your normal medications except diabetic medications

Admission

You will need to go to hospital at least 2 hours prior to the surgery, to prepare for surgery and for your stay at hospital. Expect to be an inpatient for 3-4 days. Your length of stay in hospital will depend on your ability to get up on crutches or a frame, so time spent in training prior to surgery will be valuable.

Surgery

The surgery is usually performed under general anaesthetic with a "popliteal block" – this is the same as an epidural but placed at the knee. It will make your leg numb below the knee for 1-3 days and provides excellent pain relief. Normally the pain from surgery is very well controlled and most patients are comfortable. You will be given analgaesics to take home with you for several days.

The incision is over the front of the ankle and in an ’S’ shape to avoid the ankle crease and wound healing problems. The arthritic surfaces of the joint are removed using exact alignment jigs, and any pre-existing deformity is corrected at this stage. At times this may require further simultaneous procedures to realign the heel or the foot. The implants are locked in place and the high molecular weight polyethylene articulation inserted. Care is taken to suture the wound and a plastercast ‘backslab’ applied. The operation takes approximately 2 hours.

Risks of surgery

Swelling

Initially the foot will be very swollen and needs elevating. The swelling will disperse over the following weeks & months but will still be apparent at 6-9 months.

Infection

This is the biggest risk with this type of surgery. Smoking increases dramatically. You will be given intravenous antibiotics to prevent against it. The best way to reduce your chances of acquiring an infection is to keep the foot elevated for 10 days. If there is an infection, it is usually mild and resolves with a course of antibiotics. Rarely, it can be severe requiring further surgery.

Nerve Damage

Alongside the incision are three nerves – the deep & superficial peroneal and the saphenous nerves. They supply sensation to the side and the top of the foot and toes. They may become damaged during the surgery and this will leave a patch of numbness, either at the side of the foot or over the top of the foot and toes. This is usually temporary but may be permanent. There is approximately a 10-15% of this happening.

Wear of the replacement

The metal / polyethylene joint has an unknown lifespan at present. When it fails, it is either due to infection or wearing away of the polyethylene. This usually takes several years; we do not have an average longevity yet. Once the joint wears out, further surgery is normally required to fuse the joint together. Hopefully, this never becomes necessary, but a 10-15 year period is a reasonable estimate for the survival of the ankle joint.

Dislocation

This is rare.

Post Operative Care

The nurses will momitor you carefully to ensure a full and comfortable recovery. They will show you how to bath and dress and self-care. The physiotherapists will check that you are safe mobilising and that you are able to cope at home. Expect to be on the ward for 3-4 days.

Outpatient follow up

• At 2-3 weeks, for inspection of the leg and wounds and removal of stitches. If all is well, you can start walking on the ankle in a protective Aircast boot. Physiotherapy to the ankle should start then, aimed at reducing swelling and regaining maximum movement and function.
• At 6 weeks, 12 weeks and 24 weeks with an xray. Annually thereafter.

Recovery from surgery

This is significant surgery and patience will be required in a aiding a gradual recovery process. Strict elevation for many days after the procedure is necessary to control swelling and improve wound healing.

• Expect swelling for over one year! A long compression sock can help with this.
• Expect discomfort for 3-4 months.

Activity, driving and time off work

• In general, 4 weeks off work is required for sedentary posts
• 8 weeks for standing or walking posts
• If you are a farmer, gardener or involved in similar active pursuits it may be 12 weeks before you can begin to put large strain on the joint
• Driving should be possible after 4-6 weeks.
• It will take 4-6 months for you to be able to walk for over ½ hour.