Original Editors - Pieter Jacobs
- 1 Definition/Description
- 2 Clinically Relevant Anatomy
- 3 Epidemiology /Etiology
- 4 Characteristics/Clinical Presentation
- 5 Differential Diagnosis
- 6 Diagnostic Procedures
- 7 Outcome Measures
- 8 Examination
- 9 Medical Management
- 10 Physical Therapy Management
- 11 Clinical Bottom line
- 12 References
Peroneal tendinitis is a condition that can be acute or become chronic (peroneal tendinopathy) whereby there is an irritation to one or both peroneal tendons with subsequent degeneration and inflammation.
Clinically Relevant Anatomy
The peroneus longus and peroneus brevis muscles reside in the lateral compartment of the lower leg and are innervated by the superficial peroneal nerve. The peroneal tendons receive their blood supply from the peroneal artery and the tibialis anterior artery. There are 3 avascular zones that may contribute to tendonitis: in both the tendons at the turn around the lateral malleolus and in the peroneus longus tendon where the tendon curves around the cuboid. 
The peroneus longus arises from the head and proximal two-thirds of the lateral surface of the body of the fibula and the origin of the peroneus brevis is located on the distal two-thirds of the lateral surface of the body of the fibula, medial to the Peroneus longus. Both muscles become tendons proximal to the ankle joint and pass posterior to the lateral malleolus in a fibro osseus tunnel, the retromalleolar groove. This groove is formed by the superior peroneal retinaculum (SPR), the fibula, the posterior talofibular ligament, the calcaneofibular ligament and the posterior-inferior tibiofibular ligament. Both peroneal tendons are in a common synovial sheath behind the lateral malleolus, where they are held in place by the superior peroneal retinaculum to prevent subluxation of the ankle. Distal to the fibula, the tendons travel within individual sheaths, separated by the peroneal trochlea on the lateral surface of the calcaneus. The peroneus longus tendon turns medially between the cuboid groove and the long plantar ligament and inserts onto the plantar surface of the base of the first metatarsal and the lateral aspect of the medial cuneiforms. The peroneus brevis tendon continues directly to its insertion onto the tuberosity (base) of the fifth metatarsal. Therefore the peroneus longus tendon remains posterior and inferior to the peroneus brevis until the lateral aspect of the foot.
The actions of the peroneus longus and brevis are plantarflexion and eversion of the foot in open kinetic chain motion. During weight bearing, the peroneus longus acts as a stabilizer of the transverse arch of the foot, as well as a stabilizer of the first ray during propulsion 
Peroneal tendonitis is common in running athletes (particularly endurance running due to a high number of cyclic muscle contractions), young dancers, ice skaters and sports requiring frequent change of direction or jumping such as basketball, skiing and even horse riding  The lesion may be due to partial tears, complete ruptures, subluxation, tenosynovitis, a fractured os peroneum, or damage to the peroneal retinacula. Chronic lateral ankle instability and excessive subtalar and ankle varus rotation may cause damage to the peroneal tendons and their associated structures. Contributional factors for the development of peroneal tendonitis are tight calf muscles, inappropriate training, poor foot biomechanics such as over-pronation of the foot or excess eversion of the foot, inappropriate footwear and muscle weakness of them. peroneus longus.  Other causes include severe ankle sprains, repetitive or prolonged activity, direct trauma’s, chronic ankle instability, fractures of the ankle or calcaneus, and peroneal tubercle hypertrophy. 
Tendonitis, in general, occurs when an individual returns to activity without proper training or after a period of extended rest. Specifically for athletes, the type of footwear, training regimen and training surface can contribute to the problem. For workers increased hours, changes in workstation or changes in the type of labour can contribute to symptoms.
Patients with peroneal tendonitis present with pain and, occasionally, swelling and warmth in the posterolateral aspect of the ankle along the course of the peroneal tendons.
- Peroneus brevis tendonitis is usually symptomatic from the lateral malleolus distally to its insertion at the base of the fifth metatarsal.
- Peroneus longus tendonitis is characterized by tenderness over the lateral calcaneus, often extending distally to the plantar aspect of the cuboid.
Patients may relate exacerbation with rising onto the ball of the foot, running (lateral running, figure-8 running), cutting, jogging, or walking on uneven surfaces or following these activities or following a rest period, especially upon waking in the morning. The pain tends to be of gradual onset which progressively worsens over weeks or months with the continuation of aggravating activities. Acute tendonitis presents with recent (<6 weeks) onset of pain along the lateral ankle and foot .
Peroneal tendinopathy can be difficult to distinguish.
- Ankle Sprain: anterior drawer test, talar tilt test
- Ankle fractures: Ottawa ankle rules
- Os Trigonum syndrome: MRI, passive forced plantarflexion
- Chronical lateral ankle pain with other cause: MRI 
- Longitudinal peroneal tendon tear: MRI 
- Peroneal subluxation: ultrasonography, CT, MRI or peroneal tenography 
- Flexor Hallucis longus tendon injury 
A thorough subjective and objective examination from a physiotherapist can be sufficient to diagnose peroneal tendonitis.
Plain film radiographs do not reveal soft tissue abnormalities; however, they are useful for excluding arthritis, bone abnormalities such as pes cavus, or fractures.
In chronic cases, or in cases which may be difficult to differentiate from lateral ankle ligamentous injury, computed tomography or magnetic resonance imaging may be helpful. T2-weight MR images often show visible accumulation of fluid within the peroneal tendon sheath. Thickening of the synovial lining may be appreciated with high-definition images. Tenography may be especially helpful in the chronic setting with suspected stenosis within the tendon sheath. 
- LEFS (Lower Extremity Functional scale): the objective of the Lower Extremity Functional Scale (LEFS) is to measure "patients' initial function, ongoing progress, and outcome" for a wide range of lower-extremity conditions. It can be administered to determine the level of difficulty of various functional tasks with a lower extremity disability and is scored from 0-80, with 80 indicating no limitations 
- FAAM (The Foot and Ankle Ability Measure): it is a self-report outcome instrument consisting of 29 questions to evaluate the physical function of patients with food or ankle disabilities. The questionnaire is divided into two subscales: activities of daily living and sports.
A thorough history should be taken prior to the examination.
- Attention should be paid to the overall alignment of the leg and posture of the hindfoot. Patients with hindfoot varus may subject the peroneals to increased forces that predispose to injury, or the varus might result from peroneal weakness.
- Look for the presence of swelling over the posterolateral aspect of the ankle.
Feel for warmth and muscle guarding and tenderness along the course of the tendons. Passive hindfoot inversion, passive ankle plantarflexion, active-resisted hindfoot eversion and active-resisted ankle dorsiflexion provokes pain posterior of the lateral malleolus. 
Range of motion:
Examination frequently reveals the painful limitation of subtalar joint range of motion secondary to muscle splinting. Pain may also be demonstrated with passive plantarflexion and inversion, or active dorsiflexion and eversion of the foot.
Muscle testing evaluation shows decreased peroneal muscle strength. The peroneal muscles can be isolated from each other by the peroneus longus and brevis tests If the peroneus brevis tendon alone is affected, the pain is located posterior and distal to the lateral malleolus. Peroneus longus tendonitis presents with pain along the lateral calcaneal wall extending to the cuboid. 
- A provocative test for peroneal pathology has been described. The patient’s relaxed foot is examined hanging in a relaxed position with the knee flexed 90°. Slight pressure is applied to the peroneal tendons posterior to the fibula. The patient then is asked to dorsiflex and evert the foot forcibly. Pain may be elicited, or subluxation of the tendons may be felt. 
- Testing of lateral ankle ligaments: lateral ankle ligamentous stability should be checked with the anterior drawer and ankle tilt test.
The primary aim of treatment is to afford pain relief, restore mechanics and return the patient to their desired level of active participation. Patients diagnosed with peroneal tendinitis can be treated with non-steroid anti-inflammatory medication (NSAID) and decrease the level of the activity in order to relieve pain.  There is lack of evidence for the use of corticosteroid.  Also, the use of lateral heel wedges can help to manage mild cases peroneal tendinitis
If nonoperative treatment is ineffective or failed after 3 to 6 months, an open tenosynovectomy is recommended. Postoperatively:-Patients are made non weightbearing during the first 2 weeks. Then they are placed in a short leg weight-bearing cast or boot. Range of motion exercises and strengthening activities (eccentric exercise) are started 2 to 4 weeks after surgery.
Physical Therapy Management
Treatment for peroneal tendonitis includes a program of stretching, strengthening, mobilisation and manipulation, proprioceptive and balancing exercises , icing, ankle bracing or taping during contact sports If symptoms are severe, a cast or ROM boot immobilisation is prescribed for 10 days. After symptoms resolve, the patient begins a progressive rehabilitation programme along with a gradual increase to full activity.
Also extracorporeal shock wave therapy (ESWT), acupuncture are used to treat tendinopathy. But there is only limited evidence from studies for these treatments.
There is evidence for using manual therapy, specifically the lateral calcaneal glide: To mobilize the left calcaneus, the patient is in left side lying with the calcaneus hanging over the table. The foot is held in a neutral position with the talus stabilized while the therapist performs a medial to lateral glide (in the transversal plane).
Clinical Bottom line
Tendinitis is the inflammation of a tendon resulting from micro-tears. These tears happen during an acute overload of the tendon from too heavy or sudden forces. This pathologic process leads to pain, swelling and decreased strength and flexibility of the tendon.
- A S. International Advances in Foot and Ankle London: Springer-Verlag Limited; 2012. (level of evidence 1A)
- Scanlan RL, Gehl RS. Peroneal tendon injuries. Clin Podiatr Med Surg. 2002. (level of evidence 4)
- DS Heckman, Gluck S G, SG. Parekh. Tendon Disorders of the Foot and Ankle, Part 1: Peroneal Tendon Disorder. Am J Sports Med. 2009. (level of evidence 5)
- MT Pfefer, SR Cooper, NL. Uhl. Chiropractic Management of Tendinopathy: a literature synthesis. Journal of Manipulative and Physiological Therapeutics. 2009. (level of evidence 1A)
- ML Omey, JM. Lyle. Foot and ankle problems in the young athlete. Medicine & Science in Sports & Exercise. 1999. (level of evidence 3A)https://www.themichelicenter.com/publications/media/Ref91a%5B1%5D.pdf
- Zgonis T, Jolly GP, Polyzois V, Stamatis ED. Peroneal tendon pathology. Clinics in podiatric medicine and surgery. 2005 Jan 1;22(1):79-85.https://www.ncbi.nlm.nih.gov/pubmed/15555845 (accessed on 2/8/18)
- W. Grasset, N. Mercier. The Surgical Treatment of Peroneal Tendinopathy (Excluding Subluxations): A Series of 17 Patients.. The Journal of Foot & Ankle Surgery. 2012. (level of evidence 4)
- Tjin A. Ton ER Schweiter ME, Karasick D. MR Imaging of peroneal tendon disorders. AJR. 1997. (level of evidence 4)
- M. Nyska, G Mann. Unstable Ankle: Leeds: Human Kinetics Publishers; 2002.
- Baumhauer J. ankle pain and peroneal tendon pathology. clin sports med. 2004.
- park Hee jing et al, Reliability of MRI findings of peroneal tendinopathy in patients with lateral chronic ankle instability. clinics in orthopedic surgery. 2010. (level of evidence 3B)
- Fessell DP Jacobson JA. Ultrasound of the Hindfoot and Midfoot. Radiol Clin N Am. 2008. (level of evidence 4)
- Pan SL. et al, Responsiveness of SF-36 and Lower Extremity Functional Scale for assessing outcomes in traumatic injuries of lower extremities. Injury, Int. J. Care Injured. 2014.
- Davda K, Malhotra K, O’Donnell P, Singh D, Cullen N. Peroneal tendon disorders. EFORT open reviews. 2017 Jun;2(6):281-92.
- Theodoros B. Grivas Georgios E Koufopoulos, Elias Vasiliadi, Vasilios D Polyzois. The Management of Lower Extremity Soft Tissue and Tendon Trauma. Clin Podiatr Med Surg. 2006. (level of evidence 3B)
- Roster B, Michelier P, Giza E. Peroneal tendon disorders. Clinics in sports medicine. 2015 Oct 1;34(4):625-41.https://www.ncbi.nlm.nih.gov/pubmed/28736620( accessed on 2/08/2018)
- Davda K, Malhotra K, O’Donnell P, Singh D, Cullen N. Peroneal tendon disorders. EFORT open reviews. 2017 Jun;2(6):281-92.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5508858/ (accessed on 02/08/18)
- I Geert et al,. Tendon injuries of the foot and ankle in athletes. Sportmedizin und Sporttraumatologie. 2004. (level of evidence 4)
- Wukich DK, Tuason DA. Diagnosis and Treatment of Chronic Ankle Pain. The Journal of Bone & Joint surgery. 2010. (level of evidence 2A)
- PH Craiget al. Novel use of a manual therapy technique and management of a patient with peroneal tendinopathy: A case report. Manual Therapy. 2012. (level of evidence 4)
- AskDoctorJo Peroneal Tendonitis Stretches & Exercises – Ask Doctor Jo Available from https://www.youtube.com/watch?v=gzw7zufAiw0