Total Ankle Replacement

The number of total ankle replacements performed in the U.K. has been steadily rising and it is now the fastest growing prosthesis on the U.K. joint registry.

An ankle replacement is now a very good option in treating end stage ankle arthritis. Up until very recently ankle fusion was considered the gold standard and the benchmark with which all treatments would have been compared to.

At surgery, the end of the shin bone and the top of the ankle bone are resected and replaced with the implant. The is made of a metallic alloy with a plastic polyethylene spacer. 

Fusion versus replacement

This is the ultimate question and I spend many consultations discussing the pros and cons of each procedure. Clearly the gold standard would be a long-lasting single procedure which restores function and eliminates pain. Unfortunately, neither procedure fit this mould. However total ankle replacements have improved dramatically in recent years and are inching closer.

Traditionally the low demand and the very elderly and those with arthritis elsewhere in their foot were selected for the procedure. The indications and threshold have now widened, and younger patients are being considered. The advantage of a replacement is better gait patterns and range of ankle motion. In a fused ankle further stress is placed upon the neighbouring joints which are expected to compensate for the ankle stiffness. Ultimately these joints can become arthritic themselves and needing future intervention or even surgery. The clear disadvantage of a total ankle replacement, however, is the risk of failure and wear needing revision surgery. 

 

How long do ankle replacements last?

The technology has been steadily improving and the survival rates for the implants have followed. A recent study into the survivorship of the Scandinavian total ankle replacement (STAR) concluded that the implant survival rate was 93.9% at 5 years, 86.7% at 10 years, and 63.6% at 15 years. One would expect better rates with the more modern implants. I use the infinity prosthesis and use the Prophecy patient specific instrumentation. This means that the implant is fitted very accurately with instrumentation that is produced for your specific anatomy pre-designed after computer and 3-dimensional analysis of your CT scans. Better and more accurate implantation is likely to have a positive impact on implant longevity and therefore expect an increase in the survival rates as compared to the ones reported above.  This is a relatively new implant; however, it is now the most widely used in both the US and the UK. Early reports suggest good survivorships of greater than 98% in the first 3 years. 

 

What happens if an ankle replacement fails?

Once an ankle replacement has failed and further surgery is considered. The options are between revision to another prosthesis, generally a bigger implant and more complex surgery. Or to an ankle fusion. Revision surgery is more complex than the primary and the risk profile higher. 

The problem faced at the time of revision surgery is the lack of bone stock as removal of the old implant will leave a gap that will need to be filled with either a bigger total ankle replacement or with bone graft or bone substitute. 

It is important to note that total ankle replacements or not functioning as well as hip and knee replacements and there may be a need to remove the implant and revise it due to failure. research has shown that this risk is around 1 to 1.5% a year. The most common cause for failure is loosening of the components and unbinding of the bone and metal. 

 

What are the risks of total ankle replacement? 

This should be read in conjunction with the information on general complications of foot and ankle surgery which lists some of the more common risks of ankle surgery in general that may happen in around 1 in 50-100 cases. Some of the risks specific to an ankle replacement are described below. 

 

Rarely as the bony cuts are being made the residual bone stock may get weakened and subsequently fracture. This may happen acutely during the operation or it may occur subsequent to it when you start weight bearing. In most cases the fracture will result in instability of the prosthesis and as such you are likely to require surgery to fix the fracture. clearly any intraoperative fractures that are noticed at the time will be fixed during the surgery. 

The attraction of ankle replacement surgery is the preservation of ankle range of motion. however, it should be noted that this range is unlikely to be as good as a normal ankle and you are likely to have some residual restriction in the up and down motion of your ankle. The best predictor of post-operative range of motion is the preoperative range. In some cases, however the ankle maybe even more stiff and you may require intensive rehabilitation and sometimes revision surgery to improve that if necessary. Fortunately, this is a very unusual scenario and happens only very rarely. 

we have discussed the situation when the ankle replacement fails over time. In a way this is expected as the prosthesis wears and becomes loose in the longer term. Early failure within the 1st one or two years may occur due to poor bone integration to the prosthesis. The exact cause of this is sometimes difficult to establish but maybe due to micromotion, poor blood supply and smoking may play a role. In this situation an early revision surgery may be necessary. 

The medical literature suggests that as many as 5% of patients undergoing total ankle replacements will require an additional surgical intervention within the first two years. These may be to make minor adjustments to the implant itself, removing bone Spurs or impingement lesions; or to perform corrective surgery to the remainder of the foot or ankle which may have become symptomatic because of the changes resulted by the total ankle replacement. 

The nerves and blood vessels supplying the foot cross the front and back of the ankle and close to where the surgery is taking place. Clearly the location of these is known and care is taken to avoid injury and therefore injury to these structures is an extremely rare event. It is however possible to cause injury which will require further surgery and may result in permanent numbness or disability. 

The tendons that life the foot and the toes up are also at risk during this surgery, but the risks of injury is low as they are protected through out the operation. If injury is noted at surgery, then they can be repaired at the same time. This may mean the rehabilitation that follows may be altered to protect this repair. 

Risk of deep infection in joint replacement is very low and can happen in less than 1 in 100. This is because utmost care is taken at the time of surgery which is performed in a super sterile environment. Despite this deep infection can happen which present with persisting pain and discomfort and may ultimately lead to further surgery to remove the infected implant and eradicate the infection before implanting a new one or converting to an ankle replacement. In extremely rare circumstances uncontrolled infection may lead to the loss of the limb and amputation. 

Please take time to read the information I have written here.

 

Subsidiary surgical procedures 

Frequently as part of the total ankle replacement it is necessary to perform surgery to correct other deformities or ligament deficiencies within the hindfoot or the ankle. These are generally recognised prior to the surgery and discussed with you at length however at times it may become apparent only at the time of the operation that these will be required. Some examples include:

What is the rehabilitation following an ankle replacement? 

Patients who have a total ankle replacement tend to stay in hospital for one night. It is however possible to go home for the first night and have the surgery as a day case procedure. 

The surgery is performed under a general anaesthetic. It generally takes around 90 minutes to complete the operation. You will also be given a local anaesthetic block which will mean that the nerves supplying your ankle will be numbed, this means that you should not feel any pain when you come round after the anaesthetic. 

Your ankle would have been placed in a below the knee half plaster cast and you will have your leg elevated on a leg elevator. You will not be able to weight bear on the leg and this will be the case for the first 2 weeks. You will therefore need to use crutches; a knee scooter; or some other aid that will allow you to safely move around. The physiotherapist will assess you and decide on the best mobility aid.  

 

During this time, you will not be allowed to put weight on your operated foot and will need to use your mobility aid to get around. You should be elevating your leg to reduce the swelling and use ice when possible.

After the first 24 hours the nerve block would have worn off and you may experience pain from the surgery. You would have been provided with strong pain medication which you should take regularly until the pain becomes more manageable. The first two to three days are normally the worse in terms of pain experienced by patients following which the pain levels improve dramatically.

Elevating the foot can be one of the most effective pain management strategies to augment any painkillers that you take. I will review you at the end of the two weeks. To remove the plaster cast and inspect the surgical incision. I use absorbable sutures and as such there would be no need for suture removal at this stage. You will be placed in a Walker boot and if everything is satisfactory you will be able to start bearing weight on the operated leg. 

 

During this time, you will be allowed to walk fully weight bearing using the Walker boot that has been provided to you. You can take this boot off when in bed or at rest and you can also do the same when in a shower or a bath if there are no concerns with the surgical scar. 

There may be intermittent swelling that will persist in this time. Specially after weight bearing or standing and a such you should take time to rest on elevate your operated foot and continue using ice compressions.  

Gentle range of motion exercises of the ankle should also commence at this point aiming to move the foot up and down. Referral to a physiotherapist to help with this part of the rehabilitation will also be made. 

I will see you at the end of this period for x-rays and a clinical assessment. If everything is satisfactory then you will be able to discard the Walker boot at six weeks from surgery and return to wearing your own footwear. 

 

During this period, it is important to start using the ankle as normally as it is possible. I recommend that you aim to walk with a normal gait – heel to toe and gradually increasing your walking. Incremental increases of 10-20% per week are ideal. 

I would recommend starting at around 1000 steps per day at the start of this period and increase to achieve 5,000 daily steps towards the end if possible. You may need the support of a crutch or walking stick to begin with but can discard that as soon as you are confident enough. 

Physiotherapy is in full flow at this stage and you may also benefit from some water exercises in a pool. 

 

You should be comfortably walking around 5,000 steps daily and may wish to increase that at this stage. You could introduce uneven terrain and some gentle exercise such as cycling, cross trainer or swimming. 

High impact sports are not recommended if you have an ankle replacement but towards the end of this period some of my patients can start sports such as Golf or Tennis at a social level. 

You are likely to still experience swelling of the ankle after use, but this will improve towards the end of this period. Ice application and elevation should continue especially if swelling remains a problem. 

I will see you at 6 months from surgery for a final check and X-ray. 

 

I tend to keep an eye on the implant with regular X-rays. This is because sometimes bone cysts can form around the implant that are not causing any pain and on occasions may need surgery to prevent the implant from destabilising. 

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Annie Hammerton
Annie Hammerton
1 year ago

Mr Ali Abbasian has such an excellent friendly, relaxed but professional approach and always has “time” to answer what might seem “silly questions”. I leave every consultation feeling more confident in myself at needing this operation – a part of me thinks I can manage without it and there are worse thing to suffer from, but realistically my condition has deteriorated already and will worsen even more as the years go by. I actually “need” to be able to walk without discomfort. Ridiculous carrying on like this when there is a solution. Excellent website (with extra informative links) anticipating just about every question I had and addressing issues that I’d not thought about! I was able to print off every part relating to my condition and operation, which proves to be a problem on other websites. Looking forward “positively” to my ankle replacement in a couple of months time. Another box about to be “ticked off” to improve the quality of my life. Thank you Mr Abbasian, in anticipation of the relative pain and inconvenience in order that “my boots are made for walking” instead of limping!

Ali
Admin
Ali
1 year ago

Thanks Annie for your kind comments. I am glad you find this information useful.

Jo Perks
Jo Perks
11 months ago

Notes on my Ankle Replacement
Having had surgery at Guys in May I thought I could share some of my experiences in the hope that others might benefit.
Knowing that I was going to have to spend two weeks non-weight bearing following my surgery I was very anxious as to how I would cope. Having considerable issues with my wrists as well as my ankles, I knew that using crutches would be problemmatic. The physio duly appeared on the ward the following day to discuss how to manage my return home. None of the crutches he was able to offer suited the limited mobility in my wrists. He was unable to modify them either. For some reason this would compromise infection control?? Although I did finally manage to negociate the requisite four stairs, both up and down, to be allowed home, I felt the crutches were going to slip out of my grasp at any moment.
My solution to this problem was to order, on the internet, silicon crutch handle covers which can be slid over the plastic ones. I also bound some crepe banadage around the ends secured by micropore to add bulk to the ends of the handles. This helped a great deal.
The physio was able to arrange for me to be given a raised loo seat with arms to help lever myself up which was really helpful. I found that this could also double as a bidet. With such limitations on my mobility, this would prove to be most helpful. A second raised seat for the downstairs loo was also provided.
Had their been provision to assess my needs prior to going into hospital, these items could have been delivered to my home. I would have been reassured to know that I would be able to cope.
On the recommendation of a friend, who had also had surgery on her foot, I had already looked into hiring a knee scooter. This proved to be a huge advantage, ensuring that I could get to and from bed to bathroom without using crutches, particularly in the middle of the night! Some caution needs to be exercised and the warnings on the scooter to apply the brakes need to be adhered to! It cost £18 a week to hire, for a minimum of 4 weeks, and I needed mine for 5 weeks. I also ordered the additional memory foam cushion which is secured on top of the seat to really helped to reduce the pain and discomfort in one’s lower leg. It was delivered and collected without charge from my home. It cannot be used, obviously, is the bedroom and bathroom are on different levels.
I would recommend remaining mostly in one’s bedroom for the first 2 weeks. It is easier to organise keeping one’s leg elevated and thereby better managing the pain, and to keep all the medication etc in one place. I was unprepared for the 6 weeks of daily injections of heparin which I had to self inject into my stomach. Although manageable, it was by no means pleasant! And keeping up a clean supply of compression knee socks to wear on the opposite leg for six weeks as well. I also needed help in putting them on!
Showering was recommended after several days but I did not know how that could be managed without getting the plaster wet. I did have a “Limbo” full length waterproof protector from a previous operation but the plaster was too bulky to fit inside, and once that was replaced by the walker boot after two weeks, I discovered that it was too big as well. Given we have nothing to hold onto in our shower, I decided that I would have to abandon any thoughts of a shower and find other ways of washing.
Getting up and downstairs was a struggle. We had no handrails, or bannisters, on the lower section. When forced to, I managed to go down on my bottom with help to get back on my foot, but resorted to going back up on my knees whilst I was still unable to weight bear. Realising that a handrail was pretty essential to manage the stairs further into my recovery, my son and husband set about installing an extension which proved invaluable.
Keeping a daily record of what medication you have taken is a really good idea, particularly early on as it is hard to remember what you have taken and when. Some of the medication provided is pretty strong and you would not want to overdose! I set up a daily alarm on my phone to remind me to administer my heparin injection.

Two weeks after the surgery one returns to hospital to have the cast removed and a walking boot fitted. At this stage I found my left leg and ankle were still very painful so the advice to walk, ultimately without crutches, was rather unnerving. To begin with, I still kept my foot elevated as much as possible, and it was a relief to be able to take off the boot off . This is really important to limit the inevitable swelling and discomfort.
As the weather was hot, it was also an opportunity to dry out the inner liner of the boot. as it became very damp and there is no spare provided. I also discovered that one could dispense with the padded toe protector. This allowed more air to circulate. The substantial velcro fastenings were quickly mastered, if rather noisy in the middle of the night when one needed to put the boot back on again to go to the bathroom and then take it off when back in bed. The boot itself, whilst providing the opportunity to walk, which is wonderful, can cause friction and soreness so I found it best to limit the amount of time I spent walking.

I continued to need dressings to protect the suture line for 6 weeks. The hospital provided only two so it is necessary to arrange for someone to visit local chemists to source them. Had I known I could have ordered them on line before hand. Mepore 9cmsx15cms are a good size. They can also be cut down a bit later allowing the ankle more freedom of movement. As mentioned earlier, I washed both feet separately, using a stool at my bidet. An emollient, like E45, for the ankle seemed to work well keeping the wound reasonably moist. Applying a thin layer of Vaseline was alos heplful. I did have terribly dry scaly skin on my lower leg and foot which was also extremely sensitive. I have found that Aveeno Dermexa, which claims to soothe and protect very dry itchy skin, continues to be really helpful even at 8 weeks post surgery.

Sleeping was a major issue, particularly in the early weeks. It involved trying to arrange pillows in bed to raise my foot/leg to get into a comfortable position. If you can sleep on your back you are very fortunate, and will find it easier. By week 6 sleeping does become easier. I did buy a sloping memory foam pillow to keep my leg elevated in bed during the day. This would also help those who sleep on their back at night.

Given the nature of this operation and the associated issues and concerns, I felt very much in need of informed advice. If at all possible, I think that a telephone number of a nurse practioner who could allay fears and offer advice would be really helpful. Aware just how busy the nursing staff are, I was extremely reluctant to try to access advice. When I felt I had to, I contacted the Orthopaedic Dept and was put through to the Senior Orthopaedic Nurse. She was outstanding in every way. I wish I had known that her help was available early on when I developed a very bad skin rash on my back the day I was discharged from hospital.

At week 6 following my surgery, I returned to Guys Outpatients, and finally got to meet my surgeon, Mr Abbassian. I was told that I was now able to walk on my ankle without support. I was warned that progress would be slow and that I should expect it to take several more months. I know I need to persevere with my walking but it is hard to know how much pain and swelling is normal. Even now, at week 8, I have only one pair of shoes that actually fits me so that has been fairly limiting- and I am very grateful to Sketchers!

Finally, the last bit of my suture line has healed and I am walking better. Climbing stairs is easier than coming down. I am aware that there is much hard work to be done on improving the mobility of my ankle and hopefully that will be eased once the swelling has subsided.

I hope these notes might prove helpful to those undergoing the same surgery.

Ali
Admin
Ali
8 months ago
Reply to  Jo Perks

Thanks for this Jo – always useful to get information from those who are actually going through the recovery. you have provided some useful tips that I am sure other patients can find useful. Your feedback has been much appreciated.