Ankle Instability & Sprains 

What ligaments are there around the ankle? 

The ankle joint is the junction between the bones that make up your lower leg (tibia and fibula) and a bone in the foot known as the talus. The talus is held to the tibia and fibula by strong bands of tissue called ligaments. Each ligament is made up of strong fibres made from a material called collagen.

The ligament on the outside of the ankle (lateral ligament) is made up of three separate bands: one at the front (anterior talo-fibular ligament or ATFL), one in the middle (calcaneo-fibular ligament or CFL) and one at the back (posterior talo-fibular ligament or PTFL). The front band (ATFL) is the part that is usually injured in an ankle sprain, and occasionally the middle band (CFL) is also affected in more severe injuries. The ligament on the inside of the ankle (medial or deltoid ligament) is made up of two layers with the deepest part being more important to providing stability. This ligament is mainly torn in association with severe fractures of the ankle bones.

Ankle instability occurs when one or more ligaments become damaged or slack and fail to heal or respond to treatment.

How do the ligaments get injured? 

Most ankle ligament injuries happen when the foot twists inwards (inversion) beyond its normal limit. As the force of your body weight is transferred to the ankle, this can tear some or all of the fibres that make up the lateral ligaments. Occasionally small pieces of bone may be torn off with the ligaments (avulsion fracture).

In a few cases, a twisting force on the ankle may cause other damage:  the bones around the ankle may be broken; part of the surface inside the ankle joint may become chipped; ligaments connecting other bones in the foot may be sprained or torn; or the tendons around the ankle may be damaged.

What should I do if I sprain my ankle? 

Most ankle sprains are will improve with simple measures:

  • Rest – take the weight off the injured joint as much as possible for a day or two. For most mild sprains, it is best to start taking some weight on the injured ankle within 2-3 days to stop the muscles from weakening.

  • Ice – apply an ice pack (a small bag of frozen peas wrapped in a towel is ideal) three times a day for 15 minutes to reduce swelling.

  • Compression – consider strap the ankle with a snug bandage to help reduce swelling.

  • Elevation – ideally rest your ankle above the height of your chest since gravity can then help fluid to drain away from the injury to reduce swelling (and pain) more effectively.

Normally a sprained ankle will recover within 6-8 weeks, although swelling tends to take a few weeks longer.

When should I go to the emergency department? 

You should attend your local hospital’s emergency department or minor injuries unit if you have a severe injury. The following may suggest a severe injury:

  • Your ankle is so painful you cannot put any weight on it.

  • Your ankle looks deformed.

  • The skin over your ankle is broken.

  • The injury was caused by a severe force such as a fall from a height or a blow from a heavy object.

  • The pain and swelling gets worse, rather than better, after the first 3-4 days. Please note that bruising often gets worse for a week or more before it starts to fade and frequently tracks down into the foot.

Do I need physiotherapy or an operation? 

Most simple sprains will get better without any special treatment. However, if you have a severe injury or the initial injury does not recover normally, it is usually best to see a physiotherapist initially. They will help to re-train your ankle to respond to various movements by doing different exercises and activities; this is known as proprioceptive physiotherapy. If your ankle or Achilles tendon are stiff, you will also be shown exercises to stretch these, and the strength of the muscles around the ankle will be increased by exercises. If your foot shape makes you prone to extra stress on the ankle ligaments, a moulded insole may be advised for your shoe to reduce these stresses.

You cannot absolutely prevent another injury, but there are things you can do to reduce the risk. This includes taking care when walking to avoid twisting your foot on uneven pavements, cobbles etc. High-heeled shoes put extra stress on your ankle and should be avoided. If your ankle or Achilles tendon are stiff this puts extra stress on your ankle ligaments when you walk or run, and exercises would probably improve this.

In some people, going over on the ankle can persist despite physiotherapy. At this point, the opinion of an orthopaedic foot and ankle surgeon would be helpful. They will examine your ankle and might organise an x-ray or scan of it. Depending upon the findings, the surgeon may suggest an exploratory operation on your ankle (arthroscopy) to check on the state of the ankle joint and possible repair of the damaged ligaments.