Peroneal tendonitis – Do regenerative medicine treatments work for tears?

Marc Darrow, MD, JD

Someone who has been suffering from chronic ankle problems may eventually receive a diagnosis of peroneal tendonitis or peroneal tendinopathy. This is an injury to the peroneal tendons in the ankle. If there is inflammation in the ankle area, the diagnosis would be peroneal tendonitis, the “itis” signifying inflammation. Little or no inflammation, the problem would be considered more chronic in nature and considered a disease of the tendon or “tendinopathy”

Peroneal tendon injuries are considered common but the injury can be complex and misdiagnosed

While peroneal tendon injuries are considered common, the injury can be complex, an an MRI evaluation may not provide an accurate assessment. This was discussed in a 2021 paper (1) in The Journal of foot and ankle surgery. The doctors here write:

“Peroneal tendon pathology is commonly associated with chronic lateral ankle instability. Foot and ankle surgeons often rely on preoperative magnetic resonance imaging (MRI) for identification of related pathology and surgical planning in these patients.”

What the doctors found was the pre-surgical MRI did not help as much as hoped for. During surgery doctors were able to identify peroneal tendon damaged in 92.7% patients MRI identified in 48.8% of those same patients.

A paper in the journal Foot & ankle orthopaedics (5) explained it this way: “For the patient who presents with lateral ankle pain, the differential diagnosis includes ankle sprain, lateral ligament instability, subfibular impingement, occult fracture of lateral process of the talus or anterior process of the calcaneus, osteochondral lesions of the lateral talar dome, peroneal tendonitis or subluxation, or peroneal tendon tears. These pathologies may coexist because they are frequently related to injury in inversion.”

The peroneus longus tendon and peroneus brevis tendon

The peroneal tendons are the attachments of the peroneal muscles to the bones of the ankle. There are two peroneal tendons, the peroneus longus tendon attaching the peroneus longus muscle and peroneus brevis tendon that attaches the peroneus brevis muscle. As seen in the illustration below, the muscles and tendons are on the outer side of the ankle and would be subject to tear or damage if you were to roll your ankle outwards.

In the image below we can see that peroneal tendonitis can occur when the peroneal tendons are subject to increased wear and tear and they become enlarged and inflamed leading to the tendons increased rubbing against the bones of the lower leg ankle complex.

Other factors that can lead to peroneal tendonitis include sudden increases in training or physical activity, partuclarly where weights and loads are involved. Poor choice of footwear has also been implicated.

Peroneus muscles

Polygon data were generated by Database Center for Life Science (DBCLS)[2], CC BY-SA 2.1 JP <>, via Wikimedia Commons

Chronic ankle problems and Peroneal tendon damage

The ankle area is a complex area. Damage to these tendons, as noted can occur with an acute ankle twist or sprain, chronic ankle sprains or repetitive overuse injury frequent in running or jumping sports. Peroneal tendon damage is typically suspected when significant pain is felt at the outside back of the ankle, there is obvious swelling and there is a sense of giving way when walking or running.

Even so, doctors can confuse the diagnose because as a February 2022 study points out: “Little is known regarding the impact of peroneal tendon tears on function.” This paper in the journal Foot & ankle international (2) was able to demonstrate diminished biomechanical function in patients with peroneal tendon tears. Gait analysis found significant changes in hindfoot motion, ankle motion, and ankle power. Impairments were related to the pattern and severity of the tears, and demonstrated a strong association of peroneal tendon tears with diminished ankle plantarflexion strength.”

Peroneal tendonitis treatment

The people I see still have pain in their ankles suspected of peroneal tendonitis and tears.  They also have a history of treatments that did not help them from the Rest, Ice, Compression, Elevation RICE treatments to anti-inflammatory (NSAIDs) medication to ankle braces, walking boots and shoe inserts. Some have had extensive physical therapy.

Others have had cortisone injection because nothing else was working for them. Cortisone injection is considered a last choice treatment because of the chance the cortisone may cause rupture of the tendons themselves.

The cortisone debate in Peroneal tendon treatments

cortisone  Peroneal tendon

A February 2019 stuyd in the journal Foot and ankle international (3) assessed the safety and clinical outcomes following ultrasound-guided peroneal tendon sheath corticosteroid injection for chronic peroneal tendinopathy or tears.

In this study was of 96 patients who had the corticosteroid injection

  • Twenty-four of 96 (25%) progressed to have surgery on their peroneal tendons following injection.
  • Following injection,
    • (43.7%) of patients reported 0-1 weeks of pain relief
    • (12.6%) 2-6 weeks of pain relief,
    • (6.9%) 7-12 weeks of pain relief, and
    • (36.8%) greater than 12 weeks of of pain relief.

The researchers concluded: “Our study demonstrates US-guided peroneal tendon sheath corticosteroid injection was safe and relatively effective in patients with symptomatic peroneal tendon tears or tendinopathy, including those who had undergone prior surgery, and may be considered in a comprehensive protocol of nonoperative management.”

The cortisone debate in Peroneal tendon treatments – concerns

Published in the journal Medicine (4) is this report: “Corticosteroid injections are well tolerated and more effective than other conservative treatments in the short term. Unfortunately, significant side effects have been reported as tendon degeneration and rupture. (Corticosteroid injections) can inhibit tendon repair, delay tendon sheath healing, and produce tendon degeneration.”

This is why corticosteroid injections are rarely offered for peroneal tendon problems.

Peroneal tendon surgery

Other than situations where a complete rupture has occurred, surgery is not typically recommended for peroneal tendinopathy or tendinitis. In The Journal of foot and ankle surgery (6) surgeons reported  of the success of recalcitrant insertional peroneus brevis tendinopathy successfully treated with an ultrasound-guided percutaneous ultrasonic needle tenotomy.” Needle tenotomy, it is an arthroscopic procedure where tendon tissue is cut away.

Platelet Rich Plasma – A Regenerative Medicine Injection

Platelet Rich Plasma injections are one of treatment techniques for tendon injuries. Platelet Rich Plasma injections involve collecting a small amount of your blood and spinning your blood in a centrifuge to separate the blood platelets from the red cells.

The collected platelets are then injected back into the ankle / peroneal tendon attachment areas to help stimulate healing and tissue regeneration. Platelets act as wound and injury healers. They are first on the scene at an injury, clotting to stop any bleeding and immediately helping to regenerate new tissue in the wounded area.

There is limited research specifically supporting PRP injections for the peroneal tendons. However there is much research on the use of PRP in general to treat tendon problems.

An April 2021 paper (7) wrote: “Multiple systematic reviews show efficacy of PRP in tendinopathies, early osteoarthritis, acute muscle injuries and in combination with rotator cuff repair and anterior cruciate ligament reconstruction.”

Our office has been offering regenerative medicine injections for more than 23 years. Empirical and in office data shows a benefit for many. Email me with the form below so we can assess whether or not these treatments would be viable for you.


1 Clair BL, Winder ML, Neubauer EF. Open Evaluation of the Peroneal Tendons Should Be Considered in Patients With Chronic Lateral Ankle Instability Undergoing Ankle Arthroscopy With Lateral Ankle Stabilization. The Journal of Foot and Ankle Surgery. 2021 Nov 2.
2 Chinitz N, Bohl DD, Reddy M, Tenenbaum S, Coleman S, Brodsky JW. Preoperative Gait Analysis of Peroneal Tendon Tears. Foot & Ankle International. 2021 Oct 1:10711007211036876.
3 Fram BR, Rogero R, Fuchs D, Shakked RJ, Raikin SM, Pedowitz DI. Clinical outcomes and complications of peroneal tendon sheath ultrasound-guided corticosteroid injection. Foot & Ankle International. 2019 Aug;40(8):888-94.
4 Lu H, Yang H, Shen H, Ye G, Lin XJ. The clinical effect of tendon repair for tendon spontaneous rupture after corticosteroid injection in hands: a retrospective observational study. Medicine. 2016 Oct;95(41).
5 Danna NR, Brodsky JW. Diagnosis and operative treatment of peroneal tendon tears. Foot & Ankle Orthopaedics. 2020 Apr 6;5(2):2473011420910407.
6 Sussman WI, Hofmann K. Treatment of insertional peroneus brevis tendinopathy by ultrasound-guided percutaneous ultrasonic needle tenotomy: A case report. The Journal of Foot and Ankle Surgery. 2019 Nov 1;58(6):1285-7.
7 Collins T, Alexander D, Barkatali B. Platelet-rich plasma: A narrative review. EFORT Open Reviews. 2021 Apr 1;6(4):225-35.


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