Tendonitis & Tendinosis

Subluxations & Dislocations

Tears & Ruptures


Injury and damage to the peroneal tendons can present in many forms, from tendinitis and tenosynovitis to subluxations and dislocations to even tears and ruptures. Although not common in the lower extremity, the injury can go misdiagnosed (1,4). Therefore, it is important to recognize and treat it early to prevent further, more chronic, conditions from resulting. 



There are two peroneal muscles in the lateral (outside) aspect of the leg: the peroneus longus and peroneus brevis. Both muscles start in the lower leg, course down the lateral side of the leg and ankle, where they become tendinous and then travel behind the lateral malleolus (the bony bump along the outside of the ankle). The peroneus brevis tendon then inserts into the base of the 5thmetatarsal bone, while the peroneus longus tendon continues underneath the foot and inserts on the plantar side of the 1stmetatarsal base and medial cuneiform.


These muscle act to plantarflex the ankle and evert (move outwards) the foot. The peroneus longus muscle also helps stabilize the medial column of the foot when standing.


Another important structure involved with the peroneal tendons is the superior peroneal retinaculum (SPR), which is a band of tissue that holds the tendons against the ankle, preventing them from subluxing or dislocating.
















Definition & Causes:

Tendonitis is inflammation of the tendon, whereas tenosynovitis is

inflammation of the sheath that surrounds the tendon. Peroneal tendonitis

and tenosynovitis are typically a result of overuse. Certain foot types

(e.g. pes cavus/high-arches, metatarsus adductus/c-shaped foot) also put

added stress on the peroneal tendons, which put them at increased risk for

developing tendonitis or tenosynovitis.


Clinical Exam:

Peroneal tendonitis can cause pain, swelling, and/or warmth anywhere along

the tendons, but symptoms tend to occur distal to the lateral malleolus or a

little more proximal, behind the fibula bone. The pain is worse with activities

and improves with rest.


On exam, there may be pain with inversion of the foot, because this is

causing pull of the tendons, or with resisted eversion, when the tendons are contracting. To differentiate between the peroneus longus and peroneus brevis tendons, one can follow the course of the tendons to palpate specifically where the pain is located. 


Diagnosing tendonitis is usually done clinically. If there is concern of more extensive damage, or conservative treatment options have not been successful, an MRI or ultrasound can be ordered for further evaluation.


Treatment Options:

Rest, Modification of activities, & Immobilization

Sometimes it takes a temporary modification of activities to help give the tendons a rest. This means, avoiding higher impact activities (e.g. walking, running, jumping) and switching to lower impact activities (e.g. swimming, biking) until the symptoms improve or resolve. If pain persists doing all activities, though, continued participation will only prolong, or inhibit, the healing process. Therefore, sometimes complete rest and/or immobilization in a walking boot may be necessary. 



Icing one to two times daily (especially after exercise) can help decrease inflammation. Ice should be avoided in persons with neuropathy/numbness or poor circulation. 


Anti-inflammatory medications

Anti-inflammatory medications can also help with inflammation and swelling, which, in turn, helps with pain; however, pain medications should not be used long-term.


PRP Injections

Blood is made up of plasma, red and white blood cells, and platelets. Platelets function to help with clotting of blood, but they also contain growth factors that aid in the healing process. Platelet-rich plasma, or PRP, is plasma that contains a higher concentration of platelets than normal. The purpose of PRP injections is to increase the number of growth factors into and around an area of soft tissue damage, thus stimulating and speeding up the healing process. The ultimate goal is decreased pain, improved function, and return to sports and activities.


    CLICK HERE to learn more about PRP Injections



Definition & Causes:

Peroneal dislocations (complete displacement) and subluxations (partial dislocations) most often occur among athletes. Because of the quick movements required in certain sports, certain motions can put acute and significant stress on the peroneal tendons, thus resulting in rupture of the SPR and dislocation of the tendons (4).


Abnormal anatomy can also put an athlete at increased risk for peroneal subluxation. For example, if there is weakness in the SPR or the fibular groove that the tendons sit in is shallow, these anomalies can also put the tendons at increased risk for displacement.



If the condition is chronic, the person may be able to describe having a clicking or popping sensation around the lateral ankle. Similar symptoms can be reproduced with certain movements of the ankle.


In the acute setting, diagnosing the subluxation may be more difficult because it can often present similarly to an ankle sprain with pain, swelling, and bruising around the lateral aspect of the ankle (3). Therefore, it is essential for physicians to be thorough with their examination to pinpoint the exact area of pain. Typically, with peroneal syndromes, the pain will be slightly behind the fibula bone. The pain and subluxation may also be reproduced with certain movements and tests of the ankle (1). 


Imaging Studies:

X-rays can be ordered to help rule-out an ankle fracture or other bony injury or abnormality. Unfortunately, they do not show soft tissue, though, so they are not much help with diagnosing peroneal tendon subluxations.


An MRI or ultrasound may be more helpful in detailing soft tissue pathology; however, an MRI will not pick up the subluxation or dislocation if the tendon is not displacement during the time of the exam and an ultrasound takes an experienced professional to know how to use the machine and know how to maneuver the foot and ankle to try and reproduce the subluxation while capturing the image (1).



Conservative treatment with cast immobilization can be attempted for certain cases. The goal is to allow the SPR to scar back down to the fibula (3); however, recurrence rates have been documented as high as 76% (4). Therefore, surgical intervention is often recommended, especially for athletes and recurrent dislocations (4). 


There are several different surgical treatment options available for subluxations and dislocations. They range from reattachment and/or reinforcement of the SPR to bone block procedures, fibular groove deepening procedures to prevent subluxation recurrence, and even re-routing of the tendons (3,4). 


Regardless of the procedure, associated anatomic and biomechanical abnormalities should also be addressed at the time of surgery to prevent recurrence.




Most peroneal tendon tears are the result of an acute ankle injury, but some may

occur more slowly over time. Tears in the peroneus brevis tendon occur more often

than in the peroneus longus tendon (2).


Clinical Exam:

Like other peroneal tendinopathies, pain and swelling occur along the course of the

peroneal tendons. Weakness of the involved tendon(s) may also be noted. If extensive

injury or rupture is suspected, an MRI can be performed for confirmation.


Treatment Options:

For tears (depending on the severity), conservative treatment can be tried, which is

similar to tendinitis (i.e. rest, anti-inflammatories, immobilization, modification of

activities, PT). For failed conservative care cases, significant tears, and ruptures,

surgical treatment options include tubularization or tenodesis procedures can be



1. Chauhan, Y.A., Miller, J.M. (2017). How To Diagnose And Treat Subluxing Peroneal Tendons In The Athlete. Podiatry Today, 30(1), 50-55. Retrieved from https://www.podiatrytoday.com/how-diagnose-and-treat-subluxing-peroneal-tendons-athlete

2. Dombek, M. F., Lamm, B. M., Saltrick, K., Mendicino, R. W., & Catanzariti, A. R. (2003). Peroneal tendon tears: a retrospective review. The Journal of foot and ankle surgery, 42(5), 250-258.

3. Peroneal tendon subluxation. Physiopedia. Retrieved from https://www.physio-pedia.com/Peroneal_tendon_subluxation

4. van Dijk, P. A., Gianakos, A. L., Kerkhoffs, G. M., & Kennedy, J. G. (2016). Return to sports and clinical outcomes in patients treated for peroneal tendon dislocation: a systematic review. Knee Surgery, Sports Traumatology, Arthroscopy, 24(4), 1155-1164.

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Disclaimer: The above information is meant for educational purposes only and should not be construed as medical advice. Should you feel that you are suffering from a tendon injury or another foot-related issue, please schedule an appointment to see the doctor.