High ankle sprains are injuries to the distal tibiofibular syndesmosis. They are far less common that the usual lateral ankles sprains that we see in the Pediatric Emergency Department. American football and ice hockey are the most common sports in which injuries occur, with the mechanism being an external rotation force applied to a dorsiflexed ankle. Generally this is when a foot is firmly planted and the leg is forcefully rotated during a tackle. Patients have pain in the anterolateral ankle – but in higher grade injuries the pain may be a lot more diffuse. Severe injuries limit weight bearing significantly.

On exam you can see lateral and possibly anterior ankle edema, and tenderness over the anterior inferior tibiofibular ligament and more proximally across the interosseous membrane. Patients won’t be able to hop on one foot and will experience pain upon dorsiflexion & external rotation. Sensitive signs for syndesmotic injury include tenderness over the AITFL, inability to perform a single-leg hop, and a painful dorsiflexion-external rotation test. You can also perform a squeeze test by placing the heel of each hand just above the mid calf and then compress the tibia and fibula by squeezing in the anteromedial to posterolateral directions. A “positive” squeeze test will result in the patient feeling pain in the distal syndesmosis, just above the ankle joint.

X-Rays should be obtained if you suspect a high ankle sprain. Diastasis (further apart than normal) of the distal fibula and tibia means that the syndesmosis is torn (grade 2 or 3) and this patient should be referred to Orthopedics because surgery is generally required in these cases. Any fracture also means that surgery should be considered. This can happen in a few days as long as there is no neurovascular compromise. MRI can lead to definitive diagnosis, but this is not necessary to obtain in the Emergency Department. Grade 1 injuries are fortunately the most common type.

Initial management includes non-weightbearing (crutches) with an ace-wrap or ankle lacer. Any fracture can be placed into a boot, or a below the knee splint. Ibuprofen, elevation, and ice can help. Grade 1 (no fracture and partial tears) get physical therapy whereas grade 2 and 3 (tears, disastasis, or any fracture) need surgery.

References

Vosseller JT, Karl JW, Greisberg JK. Incidence of syndesmotic injury. Orthopedics 2014; 37:e226.

Mauntel TC, Wikstrom EA, Roos KG, et al. The Epidemiology of High Ankle Sprains in National Collegiate Athletic Association Sports. Am J Sports Med 2017; 45:2156.

Prakash AA. Epidemiology of High Ankle Sprains: A Systematic Review. Foot Ankle Spec 2020; 13:420.