What is an ankle sprain?
An ankle sprain is a wrenching or twisting injury to the ankle when the ligaments are stretched beyond their capacity but no break / fracture of the bone occurs.
Why do they occur?
Ankle sprains usually occur when weight is placed through the ankle when it is not correctly aligned to cope with the load being placed on it and the ankle ’gives out’. Uneven ground is most often the cause for the ankle to be incorrectly aligned when the weight is placed on it. Landing after jumping with the foot not quite in the correct position is another cause. Finally the foot and ankle may themselves not be correctly aligned due to a congenital (inherited) or acquired (developed) condition leading to increased chance of a sprain on fairly normal terrain.
Should I have an X-Ray if I have had an ankle sprain?
Most people have had simple ankle sprains and are aware that they tend to settle in a few days/ weeks. If the injury appears more severe or there is tenderness over the bones of the ankle then you should have the ankle examined by a doctor, who will then decide whether an X-Ray is required.
If the ankle has not settled down within 3 months or if the ankle just does not feel right, then a scan may be required- some injuries/ subtle breaks/ cracks are not seen on standard X-Rays
How long do they take to settle?
Ankle sprains take a few days to weeks to settle down and if they do not there is usually a cause (e.g. damage to the tendons, cartilage).
What problems can they cause?
Pain: Initially the pain is related to soft tissue/ ligament injury, pain that persists after a few weeks may be due to cartilage damage (See: Ankle Cartilage Defects) that can occur at the time of the initial injury. It may also occur if scar tissue that develops after a sprain gets trapped in between the ankle joint surfaces at the extremes of movement (See: Ankle Impingement: Anterior). A further cause of the pain might be damage to the tendons around the ankle.
Instability: Initially the ankle will feel insecure after a sprain due to loss of proprioception (ensuring that muscles around the ankle work to prevent the ankle giving way). If a feeling of instability continues this may be due to pain (e.g. due to cartilage damage, impingement etc) or because the ankle ligaments have not healed up correctly. These factors may be exacerbated if there is a deformity in the foot and ankle. (See: Ankle Instability)
What options are there for treatment?
Exercises to strengthen the muscles around the ankle and improve the proprioception- feedback from receptors in the ankle to ensure that the muscles work at the right time.
These may help in the short term and may be required long term if the ankle remains unstable after an injury and if you wish to avoid surgery. There are a large number of braces commercially available
This may be required if you have ongoing pain or instability (see links, above), it may also be required if a break/ fracture of the bones of the ankle occurs at the time of the injury (this would therefore not be a true sprain).