Peroneal tendons are tendons that support two important foot muscles (peroneus brevis and peroneus longus) that originate on the outside of the calf. These two muscles allow you to roll to the outside of the foot while standing.
The two muscles are held in place by a band of tissue, called the peroneal retinaculum. Injury to the retinaculum can cause this tissue to stretch or tear. When this happens, the peroneal tendons can dislocate from their groove on the back of the fibula. The tendons can be seen to roll over the outside of the fibula, which damages the tendons.
Skiing, football, basketball, and soccer are the most common sports activities leading to peroneal tendon dislocation. In some cases, ankle sprains have also caused this condition. Patients usually have to use crutches after such an injury, in order to allow the retinaculum tissue to heal and the tendons to move back to their natural position on the fibula. Sometimes a splint or compression bandage is applied to decrease swelling. Anti-inflammatory medications, icing, injections, and supportive braces are often part of the treatment.
In moderate to severe cases of injury, when the peroneal retinaculum is torn or severely stretched and susceptible to dislocation, surgery may be required.