Ankle sprains and instability

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What are ankle sprains and instability?

Strong ligaments keep the bones of the ankle joint together, and these, combined with the muscles attached to the foot’s bones, are key in maintaining joint stability.

An ankle sprain, a common soft-tissue injury, occurs when the ankle’s ligaments are twisted sharply or over-stretched, leading to a partial or complete tear.

Many sprains impact the lateral ankle ligament. An ankle sprain can mean long-term ankle instability if it is not treated effectively.

What causes an ankle sprain?

The normal cause of a lateral ankle sprain is an ‘inversion injury’ in which the foot’s sole is abruptly forced inwards. Untreated, a serious sprain resulting in a complete tear may lead to long-term instability and weakness, leaving the ankle liable to collapse and for injury to recur. With serious sprains, tiny pieces of bone may also shear away at the point where the ligament attaches. Exercising on bumpy surfaces, falling, or twisting the foot while participating in sport are other causes of sprains.

What are the symptoms of an ankle sprain?

Symptoms include:

  • Bruising, pain and swelling are typical, but it may still be possible to put a certain amount of weight on your foot
  • A feeling that your ankle is ‘catching’ or locking
  • Lack of stability in your ankle causing the ankle to give way frequently
  • Possible ankle dislocation or osteochondral injury (defect in the cartilage at the tip of the bones)

How is an ankle sprain diagnosed?

Often an X-ray is done on patients suffering sprains, to exclude the possibility of a fracture. Your consultant may also organise an MRI scan to assess the extent of ligament injury, peroneal tendon issues (tendons in the foot running side by side behind the outer ankle bone) and look for bits of loose bone.

How is an ankle sprain treated?

An ankle sprain won’t normally need an operation. Instead you will be instructed to rest your ankle, lift it above the level of your heart as often as you can, and treat it with an ice pack to keep the initial swelling to a minimum.

The application of compression dressings or a removable boot to immobilise and support the joint can also be beneficial, depending on the severity of your sprain. Anti-inflammatory painkillers may also be recommended, together with some non-strenuous physiotherapy to help strengthen the joint and prevent stiffness.

Surgery: should your ankle remain painful or not restabilise after two or three months, your consultant may perform an arthroscopy (keyhole surgery) for a detailed assessment and repair of the joint; alternatively he may decide ankle ligament reconstruction surgery (lateral ankle sprain surgery) is necessary to restore the torn ligament. A personal rehabilitation programme with a physiotherapist will then be put in place to restore strength, range of movement and balance.