What is it?
A sprain of the ankle refers to injury/damage of one or more of the ligaments of the ankle joint. The ligaments are strong pieces of collagen tissue that attach from one bone to another separate bone across a joint. They are a form of passive stability and together with active stability provided by the muscle-tendon unit, keep the joint position and load bearing cartilage in good congruency.
How did I get it?
A sprain occurs when a joint is put in a position towards the extremities of its normal range of movement resulting in tensioning of the ligament. Damage to the ligament occurs when an applied force to this extreme position is greater than the breaking strain of the ligament. The subsequent sprain may involve damage to some or all of the fibres of the ligament. In the ankle this can occur when the foot inverts (balancing on the outside of the foot) and your bodyweight applies a force to the lateral ligament resulting in a sprain.
What does it feel like?
An ankle ligament sprain will be painful over the area over the ligament. This is usually associated with early swelling and bruising. There may be an associated odd feeling with the sprain as sensory receptors within the ankle ligament have been compromised. Instability is common especially on uneven surfaces.
How is it diagnosed?
A description of the symptoms and the event which lead to the injury is a good indicator of potential sprain sites. An inverted foot posture leads to lateral ligament sprain. This is the most commonly injured ligament in the ankle. An everted foot position indicates a medial ligament sprain. Medial ligament sprains are less common but often more serious. Hyper extension of the ankle or a dorsiflexed, externally rotated ankle often results in a high ankle sprain. Specific testing and palpation of each of the ligaments also is very reliable. Ultrasound and MRI are good for diagnosing the degree of injury and detecting concomitant bone, tendon and chondral injury.
How do I fix it?
- Lighter grade injuries respond well to RICE- Rest, Ice, Compression and Elevation. There may be some stiffness but this generally settles after the ligament has had time to repair. Recovery from a grade 1 injury will take between 2-4 weeks to complete. Strength and proprioceptive retraining should start after a week and once walking is relatively pain free.
- Higher grade injuries should be assessed by a professional because larger strains of the ligament may require early immobilisation to allow proper healing. Associated chondral damage and fracture are not uncommon sequelae of a sprain. Strength and proprioception exercises should be commenced after pain settles. Stiffness is greater in high grade sprains and may require joint mobilisation to restore full range of motion.
- Grade 2-3 high ankle sprains may require immobilisation in a boot initially and a period of non weight bearing.
Will I need surgery?
Surgery may be required for higher grade ligament sprains when conservative measures have failed to address instability issues. Damage to the higher ankle ligaments which provide the stability of the mortise will require fixation if the mortise displays widening on weight bearing x-rays.
How do I stop it coming back?
Ligament damage disrupts the ability of the sensory receptors in the ligament to detect ankle position and can therefore contribute to further ankle ligament sprain. Muscles stabilisers may also be inhibited early after ankle sprain. Proprioceptive retraining helps to re-educate these sensors and detect perturbations of the ankle. Peroneal strengthening exercises are important if there is any instability due to ligament laxity. This provides some preventative measures. Any remaining instability will benefit from taping and ankle support braces.