eMedicine Specialties > Sports Medicine > Lower Limb

Peroneal Tendon Syndromes

Steven Karageanes, DO, Director, Primary Care Sports Medicine Fellowship, Director, Sports Medicine Education, Center for Orthopedics and Neuroscience; Department of Medical Education, Oakwood Healthcare System
Kathleen Sharp, MD, Sports Medicine Fellow, Department of Family Practice, Henry Ford Hospital
Contributor Information and Disclosures

Updated: Sep 2, 2008

Introduction

Background

Injuries to the peroneal tendons are common but not always clinically significant.¹ They are misdiagnosed as a lateral ankle sprain most of the time, because isolated injury to the peroneal tendons is rare.^{2, 3} Injury can occur in one or both peroneus longus and brevis tendons and is typically classified as acute or chronic. Function can be severely compromised by any tendon disruption; conversely, complete tendon rupture can be asymptomatic. Lesions have been seen in symptomatic patients, as well as in cadaver studies of patients who were presumably asymptomatic.⁴ The reason for this variation is not known.

Acute injuries of the peroneal tendons include tendinitis, tear/rupture, laceration, and dislocation/subluxation. Acute injuries typically have 1 of 2 mechanisms as the cause: (1) inversion ankle injury, which is often seen with associated anterior talofibular ligament and/or calcaneofibular ligament disruption, and (2) a powerful contraction of the peroneal muscles with a forcefully dorsiflexed foot.

Chronic injuries include longitudinal tears^{5, 6, 7, 8, 9} and recurrent subluxation^{10, 11, 12} of the peroneus brevis tendon.¹³ These chronic injuries are usually associated with ankle or subtalar arthritis and ankle instability. People with "bad" or "weak" ankles may have peroneal tendon pathology. Core and lower extremity biomechanics must be evaluated in any chronic atraumatic peroneal tendinopathy, as flaws in those mechanics are usually the culprit.

For excellent patient education resources, visit eMedicine's Foot, Ankle, Knee, and Hip Center and Sprains and Strains Center. Also, see eMedicine's patient education article Ankle Sprain.

Frequency

United States

The occurrence of injuries to the peroneal tendons is not actually known. DiGiovanni et al found that 25-77% of patients with chronic lateral ankle instability had some type of injury to the peroneal tendons.¹⁴ Over 33 months, Fallat et al noted that of 638 acute ankle "sprains" seen at the Oakwood Hospital Downriver Center Emergency Room and Occupational Medicine Clinic in Dearborn, Michigan, only 83 involved damage to the peroneal tendons, whereas more than 450 involved the anterior talofibular ligament.¹

Functional Anatomy

The peroneal tendons originate in the lateral compartment of the leg. The peroneus longus originates from the head and proximal two thirds of the fibula, whereas the peroneus brevis originates from the distal two thirds of the fibula. Both tendons have a musculotendinous portion that courses just below the lateral malleolus.

At the posterior aspect of the lateral malleolus, the peroneal tendons lie within the fibular groove, with the peroneus brevis medial and anterior to the peroneus longus. The fibular groove forms the anterior border of the fibro-osseous tunnel that the peroneal tendons course through. The inferior retinaculum and the calcaneofibular ligament form the posterior border.

The posterior talofibular and the calcaneofibular ligaments form the medial border. The superior retinaculum forms the lateral border. Just inferior to the lateral malleolus, the peroneus brevis courses anteriorly, crossing over the cuboid to insert on the fifth metatarsal styloid.

Inferior to the peroneus brevis, the peroneus longus turns beneath the cuboid in a tunnel formed by the long plantar ligament and the groove of the cuboid. It then courses to insert onto the first metatarsal and medial cuneiform. In 20% of the population, an os peroneum may be present within the peroneus longus tendon as it turns under the cuboid bone. In 0.1% of the population, a structure known as the os vesalianum—a sesamoid bone—is found at the insertion of the peroneus brevis tendon.

Sport-Specific Biomechanics

Most sports have elements of running and lateral movement. Sports such as soccer, basketball, and football can be highly demanding on the lower extremity.

The role of the peroneus muscles is to evert the ankle and stabilize its subtalar motion. In balancing the foot, they play off the posterior tibialis muscle on the opposite side of the tibia. Maximal exertion occurs with side-to-side movement and jumping.

The importance of the peroneus muscles is most obvious after lateral ankle sprains. Trauma to the lateral ankle distorts the proprioceptive sense and stretches the connective tissues. The peroneus muscles are often stretched and injured from traction when the foot inverts.

Ankle instability ensues and continues until the lateral retinaculum heals, the peroneal muscles recover, and proprioception returns. If the retinaculum does not heal properly and cannot retain its tension to stabilize the peroneal tendons, symptoms of instability may not resolve without further intervention.

An analysis of overall biomechanics is essential in finding out the factors involved with peroneal tendon damage, especially when there is no traumatic insult. Leg-length discrepancies, femoroacetabular impingement, core instability, and low back pain are some of the correlated factors involved with lower extremity repetitive injuries, but little research has cemented the relationship. However, the core is the powerhouse of the body, and if foot planting is not well controlled by the hip and thigh, then extraneous forces run through the lower leg, ankle, and foot. This can only be controlled by increasing the activity of the supporting muscles, of which the peroneal tendons belong.

Clinical

History

The histories for each type of peroneal tendon injury have subtle differences. The key is to have a clinical suspicion and to listen carefully to the patient.

• Peroneal tendinitis
  • Symptoms of pain behind and distal to the lateral malleolus usually occur when the patient returns to activity after a period of time off.
  • Swelling and tenderness may also be present.
• Peroneal tendon subluxation
  • Snapping along the lateral ankle is present, with a sense of weakness or pain. A painful snapping sensation over the lateral ankle is the classic indication of peroneal tendon subluxation.
  • Pain with toe walking or cutting laterally while playing on a field are also observed.
  • With acute injury, pain and swelling are noted over the posterolateral aspect of the ankle.
  • Chronic injuries can lead to subluxation, including recurrent inversion injuries, leading to lateral ankle instability and painful snapping across the ankle.
• Peroneal tendon tears
  • With acute injury, pain and swelling are inferior and posterior to lateral malleolus. The patient may have had pain before the injury, but now the pain is debilitating and strength is decreased.
  • Chronic injury results in the subtle, insidious onset of pain posterior to lateral malleolus that progressively worsens in terms of both function and the level of pain.
• Anomalous peroneus brevis muscle injury
  • This injury can be acute or chronic.
  • The patient may have debilitating pain with the push-off portion of the stance, without a history of ankle injury.

Physical

The examination should concentrate on ankle function and stability.

• Inspection: Observe the amount and location of any swelling. Note ecchymosis and any ankle or foot deformity (the foot is in varus for acute brevis tears). Note the position of the peroneal tendons, which may be visibly subluxed without manipulative testing. Observe the patient's gait for abnormal rotation, heel strike, or weight transfer.
• Palpation: Palpate the lateral ankle ligaments and along the peroneal tendons down to their insertion sites. Palpate along the bony structures to identify possible fractures. Palpate the pulses, and check the neurovascular status.
• Specific tests: After testing passive and active plantarflexion, dorsiflexion, inversion, and eversion, a few specific tests for stability should be performed.
  • Anterior drawer test: Have the patient sit on the edge of the table with his or her legs dangling. Hold the distal tibia stable with your nondominant hand as the dominant hand pulls the posterior aspect of the calcaneus forward. Laxity indicates an injury to the anterior talofibular ligament. (see Image 2.)
  • Tilt test: With the patient seated on the edge of the table with his or her legs dangling, hold the distal tibia stable with your nondominant hand. With the dominant hand holding the calcaneus, attempt to open the lateral ankle compartment. Opening indicates an injury to the calcaneofibular ligament. (see Image 3.)
  • Peroneal tendon stability test: The operator hold the athlete’s foot with one hand, while the opposite hand gently palpates the peroneal tendons just posterior to the lateral malleolus. The operator moves the foot into end-range inversion, and then asks the athlete to evert against resistance. The other hand is monitoring the peroneal tendon, feeling for a palpable snap or translation. (see Image 5.)

Causes

Most peroneal tendon injuries are caused by the typical acute or recurrent lateral ankle sprain. As stated above, isolated injury to the peroneal tendons is rare.

• Acute injury involves forceful dorsiflexion with contraction of the peroneal muscles or an inversion injury with a high load. Most acute injuries have subacute and chronic tendinopathy.
• Chronic injury involves repeated inversion injuries, damage to the posterior talofibular and lateral malleolar retinaculum, and/or recurrent dislocation of the peroneal tendons, leading to chronic tears and lateral ankle instability.

Biomechanical factors can set up the peroneal tendons for injury. 

• Gait abnormalities must be fully evaluated and treated. Excessive eversion can pinch and put pressure on the peroneal tendons as they travel between the lateral malleolus and the peroneal trochlea.
• Severe pes planus or hindfoot deviation (valgus or varus) can be a factor.
• Equinus or restricted ankle dorsiflexion can lead to injury of the peroneal tendons.
• Anterolateral ankle impingement, particularly soon after an ankle sprain, can lead to peroneal overcompensation.
• Poor fitting equipment, such as ice skates or basketball high-top shoes, can be factors in peroneal tendon injuries.

References

• Achilles Tendonitis
• Ankle Fracture
• Ankle Impingement Syndrome
• Ankle Sprain
• Athletic Foot Injuries
• Calcaneofibular Ligament Injury
• Talofibular Ligament Injury

• Foot, Ankle, Knee, and Hip Center
• Sprains and Strains Center
• Ankle Sprain Overview
• Ankle Sprain Causes
• Ankle Sprain Symptoms
• Ankle Sprain Treatment