Ankle instability: presentation and management

The ankle joint is akin to a mortise. Damage to this mortise joint with injury to either the medial, lateral or syndesmotic complex can result in chronic ankle instability. In this article we discuss the management of ankle instability, most commonly arising from injuries to the lateral ligament complex. Chronic ankle instability may develop from an inversion-type ankle sprain, usually affecting the anterior talo-fibular ligament (ATFL). Most affected patients improve with conservative management following this injury, but up to 30% of patients can develop debilitating chronic ankle symptoms. In assessing ankle instability it is important to differentiate between patients with functional instability and those with mechanical instability. Clinical assessment is the cornerstone of diagnosis, although stress views performed under anaesthesia (including the contralateral ankle for comparison) are useful. MRI is helpful in the assessment of soft tissue and cartilage injury. Short periods of immobilisation and physiotherapy are the mainstay of acute treatment. Patients with functional instability may benefit from peroneal strengthening and proprioceptive rehabilitation. Surgery is recommended for patients with mechanical instability who fail conservative treatment. Anatomical ligament repair has the best results. Non-anatomic ligament reconstruction is reserved for revision cases although primary ligament reconstruction may have a role in selected cases.