The ankle is the most traumatised part of the body and accounts for between 10–30% of all sports-related injuries. Chronic ankle instability is one of such injuries that commonly develops from repeatedly spraining your ankle. So, we spoke to Mr Jordi Sanchez-Ballester to understand exactly what this injury is, how it can be diagnosed and how it can be treated.

 

 

What is chronic ankle instability?

Chronic ankle instability is a condition in which the ankle repeatedly gives way - most commonly occurring to the outer (lateral) side of the ankle. This condition usually develops after repeated ankle sprains. In about 20% of acute ankle sprain cases, patients go on to develop chronic ankle instability.

 

Three ligaments in the outer side of the ankle often get damaged:

 

• Anterior talofibular ligament (ATFL)
• Posterior talofibular ligament (PTFL)
• Calcaneo fibular ligament (CFL)

 

Usually, patients describe that their ankle gives way while walking or doing other activities, however, it can also happen when you’re just standing. The failure of functional rehabilitation after a significant acute ankle sprain can be another factor that leads to the development of recurrent ankle instability.

 

How do you treat a sprained ankle?

Treating an ankle sprain appropriately the first time will very often prevent it from recurring. However, most ankle sprains are fairly minor injuries that get better with simple self-care treatment (RICE).

 

• Rest — take the weight off the injured joint as much as possible for a day or two. Try to exercise and stretch the injured ankle as soon as possible after the injury.
• Ice — an ice pack (a small bag of frozen peas or corn is ideal) can be applied for 10-15 minutes 3-4 times a day to reduce swelling
• Compression — a firm bandage or strapping will help to get swelling down
• Elevation — resting with the ankle above the height of the body will allow swelling to drain away into the bloodstream

 

For a severe injury or an initial injury that does not recover normally, it is usually best to see a physiotherapist. The hospital A&E or orthopaedic department, your GP or sports club can arrange this for you.

 

Normally, a sprained ankle will recover within 6-8 weeks, however, you may still see some swelling for a few weeks longer. Recent evidence has shown that taping, bracing and neuromuscular training are effective measures to prevent recurrent ankle sprains in sports activities.

 

How do you test for ankle instability?

Taking a history and physical examination are useful tools to identify areas of pain and for comparative analysis of mobility and laxity (ligament testing, anterior draw and inversion tests). There are also other tests including:

 

• radiological tests
• weight-bearing plain X-rays (stress X-ray)
• dynamic images to confirm and quantify laxity
• more sophisticated techniques such as an ultrasound and MRI arthrograms to identify ligament, tendon and cartilage damages

 

Is ankle instability dangerous?

There are suggestions in literature and it is from my experience that a persistent lateral ankle ligament instability (sprain) causes unbalanced loading of the medial joint of the ankle, which could, in turn, lead to the development of osteoarthritis (OA) of the ankle.

 

What causes recurrent ankle instability?

Most ankle ligament injuries are caused when the foot twists inwards and is pointing downwards rather than flat on the ground. When this happens, the foot may stretch and some tearing can occur to its fibres (sprain). It can also tear completely.

 

If there is a major injury of the anterior talofibular ligament, the forces transfer to the calcaneofibular ligament and the tibiofibular ligaments, which may also be sprained or torn.

 

Occasionally small pieces of bone may be torn off with the ligaments or a piece of the joint surface inside the ankle may be chipped off. Recurrent ankle instability often develops after repeated ankle sprains.

 

How can you fix ankle instability?

Most patients with ankle instability will not need an operation. Even if your ankle still feels unstable after physiotherapy, you could try a brace rather than having an operation to tighten it or replace the ligaments.

 

The nerve endings (proprioceptive nerves) of the ankle in most patients suffering from ankle instability are not working properly. Therefore, the first treatment is a physiotherapy programme to re-train these nerves through various exercises and activities to respond properly to the movements of the ankle. If your ankle is stiff, you will be shown exercises to stretch it. The strength of the muscles around your ankle will also be increased by these exercises.

 

If your natural foot shape makes you prone to extra stress on the ankle ligaments, then you may be advised to insert a special, moulded insole into your shoe to reduce these stresses.

 

Many people will find their ankle is much more stable and comfortable after approximately three to six months of physiotherapy. However, problems can continue for some patients which, at this point, the opinion of an orthopaedic foot and ankle surgeon would be helpful.

 

If you have not already had the special tests mentioned above, then these may be done now. The surgeon may also suggest an exploratory operation on your ankle (arthroscopy) to check on the state of the joint in addition to a dynamic test (while under anaesthesia) to assess the stability of the ligaments. If these tests suggest weakness of the ankle ligaments, a further operation may be advised.

 

What does surgery for treating ankle instability involve?

There are two main types of surgeries:

 

• Arthroscopy (keyhole) and stress views of the ankle — this procedure will establish the degree of instability, and often with the debridement of the scar tissue of the injured ligament, patients will find their ankle much more stable and comfortable. No further intervention would be necessary in this case. However, if following the arthroscopic procedure the patient still experiences pain and instability in the ankle, a repair of the ligaments would be advised.
• Modified brostrom-gould repair — this is the most common procedure that I perform. The damaged ligaments are tightened and re-attached to the bone. It aims to achieve an anatomical repair of the ligaments. Another piece of tissue, usually part of one of the nearby soft tissues, is borrowed and stitched between the bones where the ligaments should be. This is done by small incisions in the outer side of the ankle. You would usually be in a plaster or brace for several weeks after the operation and would need further physiotherapy to help regain normal function.

 

What complications can occur?

Problems that may occur after a ligament reconstruction operation include:

 

• pain in the ankle, either because of damage at the time of the original injury or because the ankle is now tighter than before
• numbness or tingling down the side of the foot due to stretching one of the nerves at the time of the original injury or during the operation
• persistent swelling of the ankle

 

Mr Jordi Sanchez-Ballester is a renowned consultant orthopaedic surgeon based in St Helens and Warrington. To book an appointment with him, visit his Top Doctors profile and check his availability.