The word “arthritis” means a painful joint. Typically in arthritis, the normal cartilage that coats the bones of the joint has been eroded and hence you have “bone rubbing on bone”, which can be very painful. The ankle joint allows the foot to be pulled up and down, with the talus bone moving against the tibia or shin bone. In ankle arthritis, the normal smooth lining of the joint (i.e. the articular cartilage) is lost, meaning that the talus bone rubs directly on the tibia, which can be very painful.
Ankle arthritis can cause severe pain and disability and is as painful and disabling as severe hip or knee arthritis. Thankfully, ankle arthritis is nine times less common than hip and knee arthritis. The cause of ankle arthritis is previous ankle trauma or ankle instability in approximately 80% of patients, inflammatory arthritis (e.g. rheumatoid arthritis) in 10% and osteoarthritis in 10%.
Many patients with ankle arthritis can be managed without surgery. The main forms of non-surgical treatment include:
The ankle joint bares more weight per cm2 than any other joint in the body.
This means avoiding the activities that provoke pain and concentrating on the activities that you can tolerate with relative ease, like swimming, cycling, using a cross trainer etc.
This may involve a flexible or rigid brace to limit motion at the ankle joint and therefore limit pain. Often high lace-up boots are very helpful.
Your GP will guide you through the many painkillers that are available. Once the cause of your ankle pain has been confirmed as ankle arthritis, then it is safe to take painkillers, especially if they can help you to maintain a satisfactory quality of life. Patients typically need Paracetamol and/or an anti-inflammatory. When opiates are necessary, the pain is getting very severe, suggesting that surgery may become necessary.
Surgical treatment of ankle arthritis is only necessary when all other options have been exhausted and you have pain affecting your quality of life, despite activity modification and appropriate doses of painkillers.
Ankle replacement is being investigated, as ankle fusion is an imperfect procedure. It is slowly gaining in popularity, but has a long way to go before reaching the success of hip or knee replacement. Advantages include retaining motion at the ankle joint and having a more natural walking pattern. Disadvantages include complications in up to a third of patients, the need for continued monitoring of the implant and reports of 78% – 89% implant survivorship at five years.
An ankle fusion is getting the talus to grow into the tibia, thereby eliminating movement and bone rubbing on bone, which should completely relieve your ankle joint pain. A fusion is typically performed by putting a camera and a shaving device into the ankle joint (between the two rubbing bones) and removing any remaining cartilage and then creating two bleeding surfaces, which promotes bone healing. Once this is complete, I then place screws across the joint to compress the two bare surfaces together, in the hope that the two bones will join.
The arthroscopic (keyhole) fusion operation can occasionally be performed as a day-case (admitted and discharged on the same day). You will need a boot for 12 weeks following surgery. The boot is to support the healing process within the ankle joint and to provide additional support for the screws during healing. For the first six weeks, it is vital that you only use your heel for balance while using two crutches – our physiotherapist will show you. Weight-bearing through the boot could cause excessive movement and disrupt the healing process. If all is well on the x-ray after six weeks, you can start putting some weight on it for the second six weeks.
Complications of ankle fusion
The main complication is non-union occurring in up to 10% of patients, which means the two bones have not joined or fused. If this happens, we may need to repeat the surgery. The second complication is mal-union, whereby the joint has fused, but not as we would like it. Other complications include a low risk of infection or nerve irritation. The potential long-term complication is x-ray evidence of arthritis in the joints surrounding the ankle. Even though the arthritis is visible on your x-rays, it may not be painful or relevant.
What to expect following an ankle fusion
Following fusion, your stride length will be decreased, jumping and running will be restricted, you will walk at 90% efficiency and you will have difficulty with wellingtons. However, your foot does not become completely stiff, as the joints surrounding the ankle joint can still provide some movement. Therefore, you tend not to have a limp and should have no long-term pain.
Surgery – What to expect?
Please remove nail varnish and avoid moisturising creams. Likewise, if you have any active infections, please tell us, as your surgery may need to be deferred. Please arrange a lift home (you’ll be in the back seat) and have help available for at least the first week.
Most foot operations are performed as day case procedures, meaning admission on the day of surgery and discharge that day, assuming all is well. I will discuss the possibility of overnight admission with you, if I feel it is necessary. Most operations are performed under a general anaesthetic, and while you’re asleep, I will give you an “ankle block” to numb your foot, so you should be comfortable when you wake up after surgery. The ankle block typically works for 6 to 8 hours which allows us to start oral painkilling tablets while the block is still working. You will be given oral painkillers approximately 4 hours after your surgery by the nurses on the day ward. This overlap is to ensure excellent and continued pain relief.
Upon discharge, we give you a prescription for 3 types of painkillers:
- Paracetamol (maximum 8 tablets per day)
- An anti-inflammatory (e.g. Arcoxia)
- A morphine type painkiller (e.g. Palexia)
You may need the full cocktail of painkillers for the first 48 hours. After this period, you can start to wean off them, one by one. Firstly stop the Palexia, then the anti-inflammatory, and finally the Paracetamol.
Please remember that you have had an operation and therefore your foot will become painful if you do not take the painkillers. It is much more difficult to manage your pain if you let it develop, so please avoid playing “catch-up”. You should stop all painkillers once you are comfortable.
Mobilisation following surgery
I will tell you how much weight you can put on your ankle after your surgery. Most patients may “heel touch for balance”. This means resting the foot on the ground for balance only, and not putting any weight through the foot. Imagine you have glass or a stone in your shoe!
Most patients will be given a stiff Velcro shoe for moving around in order to protect the foot. This needs to be worn during the day, while you are up and about. In some cases, a cast or boot may be necessary, but I will discuss this with you before your operation. Our physiotherapist will educate and re-assure you prior to discharge and make sure you are safe and confident with your two crutches.
Elevation is vital
The foot always swells after surgery. It is therefore very important to travel home in the back seat of the car, keeping the foot elevated. When at home, I suggest you elevate the end of the bed with books etc. or put a duvet under the mattress, to ensure continued elevation at night. It is fine to move about the house in the first week, but keep your movements to a minimum and once you are seated, elevate the foot again. This will limit your discomfort and help the wound to heal. When showering, avoid wetting the dressing. Some patients find the use of a dressing protector/sealed bag (available in most chemists) or cling-film very useful.
It is not safe to drive, until you are allowed to ‘full weight-bear’ without crutches. This usually takes a minimum of six weeks. It is important to get clear medical advice prior to driving again.