The peroneal tendons are located on the lateral/outside part of the leg and their main function is to stabilize the ankle when walking on uneven ground such as grass or gravel. They are also important for stability when performing athletic activity. There are two tendons that are in that area - one is called the peroneus brevis and the other is called the peroneus longus. In some patients, an additional tendon - called the peroneus quartus can be found, and this is an accessory tendon/muscle that is associated with pathology of the tendons.
Diagnosing conditions of the peroneal tendons starts with a good history to understand what condition is causing the pain along the tendons. Tenosynovitis, which is inflammation of the tendons, causing swelling and pain along the course of the tendons and is commonly related to an overuse activity or starting a new athletic activity. In cases of tendinosis (degeneration or tearing of the tendon), there can be pain with daily activities, not isolated to uneven surfaces or athletic activity. Some patients may feel a sensation of snapping on the outside of the ankle. This sensation is from the tendons snapping around the bone called the fibula from an injury that has caused the tissue that holds the ligaments in places to stretch out. In severe cases of tendon degeneration, the tendon can rupture completely, although thankfully this is not common. The physical exam may demonstrate that the ankle ligaments are loose - which may be part of the reason why the peroneal tendons become degenerated. The tendons stabilize the ankle from turning in and if the ligaments are loose, the tendons are under more strain than normal and can become pathologic. The shape of the foot may demonstrate a high arch with a heel that is tilted “in”/varus - this places more mechanical stress on the tendon and the alignment of the foot may need to be addressed.
Further imaging is considered in many cases after the history and examination and includes a MRI or Ultrasound to further evaluate the tendons. In many cases, we can initiate non-surgical treatment prior to ordering further studies based on the history and examination. Many patients may benefit from the use of a lace up ankle brace to stabilize the ankle and decrease stress on the tendons. Additionally physical therapy to strengthen the muscles is a very effective method for many patients. If there is continued pain, the use of PRP (platelet rich plasma) - LINK can be considered prior to surgery. Surgical intervention to clean the inflamed tissue and repair/reconstruct the tendons if non-surgical treatment has not been successful.
