Syndesmosis injuries or the “high ankle sprain”

A syndesmosis injury is a type of ligamentous injury also known as “high ankle sprain”. It is an uncommon type of sprain that occurs in 0.5% of all ankle sprains. They can be differentiated for the most common “low ankle sprain” that affects ligaments further down in the ankle. 

 

The mechanism of injury normally involves an external rotation and eversion force that damages the inferior tibio-fibular ligament located over the lateral aspect of the ankle. It can present with associated injuries such as an osteochondral defect or a peroneal tendon injury in up to 25% of cases, as well as fractures in the ankle or other bones such as the 5th metatarsal, the lateral talar process, or the anterior calcaneal process. It is important to ascertain the level of injury to the deltoid ligament located over the medial ankle as this will have a prognostic effect. 

 

The syndesmosis is formed of a number of ligaments, which as a whole provide integrity between the fibula and tibia, resisting rotational and translational forces. 

 

The symptoms experienced will include anterolateral ankle pain, medial ankle pain if the deltoid ligament is involved, swelling around the ankle and pain on weight bearing. Through a series of examination tests your doctor will be able to suspect and diagnose syndesmotic injuries. Imaging such as X-rays or MRI scans will confirm the diagnosis, being the latter the gold standard given its accuracy and high sensitivity to diagnose ligament injuries. 

 

Once diagnosed the treatment will depend on the injury grade and instability that it produces. For mild cases, non-operative management is proposed with a combination of physiotherapy and rest. Those severe cases will benefit from surgery to stabilise the torn ligaments. 

 

A return to sports could be expected at 6 weeks for those mild cases and at 9 weeks for surgical ones. 

 

The importance of an early diagnosis is paramount for the best outcomes as when these injuries are diagnosed late the results of treatment can be compromised. 

 

 

 

Article based on a previous publication I co-authored with Dr Kal Parmar and Colin Lewin. For the original article click here.