Peroneal tendonitis is an inflammatory condition found along the course of either the peroneus longus tendon or the peroneus brevis tendon. Peroneal tendonitis occurs as a result of acute or chronic overloading of one or both of the peroneal tendons. Peroneal tendonitis results when a load is applied to the tendon that is greater than what it can sustain over time.  The location of pain associated with peroneal tendonitis is distal to the lateral ankle and just proximal to the 5th metatarsal base as seen in the image to the right.

Tendon injuries, including peroneal tendonitis, are notoriously slow to heal. The reason that tendons are slow to heal is simply due to the fact that the blood supply to a tendon is limited and extremely fragile. As a result, tendons are poorly supplied with blood and are unable to respond well in cases of injury. When a tendon is injured, the initial response to the injury is that the tendon becomes inflamed.   Inflammation is the primary means by which the body sends out a signal or call for help to manage the injury to the tendon.  Inflammation is a signal that requests increased chemical and cellular responses to the injury.  Inflammation is also the body's tool that is used to bring additional blood flow and oxygen into a specific area.

Why does tendonitis hurt? While inflamed, the tendon is actively working to repair itself. There's an acute influx of blood, oxygen and cells that results in swelling. The arrival of all these cells is a new and unusual activity in and around the tendon causing pain. Pain is simply natures way of limiting physical activity and promoting rest. Although pain is not desirable, pain is our best guide to the nature and degree of injury and will help guide choices used in healing the injury.

Treatment Of Peroneal Tendonitis

As mentioned, tendons are notoriously slow to heal. Therefore, treatment of peroneal tendonitis can take weeks to months before the problem is completely resolved. Most important in the treatment of peroneal tendonitis is the need to decrease the load applied to the peroneal tendons with each step. There are two means by which this can be accomplished.  First, begin by wearing a heel lift and avoiding walking in bare feet. The lower the heel, the tighter the peroneal tendons and subsequently the greater the load carried by the peroneal tendons.  Also avoid low heeled shoes such a loafers, slippers, etc. Calf stretching or the use of a night splint can also be of value.

Second, a lateral sole wedge may also helpful. A lateral sole wedge is a wedge placed under the lateral or outside of the shoe. A lateral sole wedge inhibits the foot from rolling out.  Limiting the outward roll of the foot decreases the load applied to the peroneal tendons.  There are a number of varieties of lateral sole wedges.  Lateral sole wedges can be placed on orthotics.  Lateral sole wedges can also be placed on the outside of the shoe by a shoe repair shop or O&P facility. 

Medical treatment of peroneal tendonitis includes the use of  ice, rest and anti-inflammatory medications.  If oral medications are ineffective, injectable cortisone is often used.  In severe cases, non-weight bearing casts may be necessary.  Walking casts may be used as long as the walking cast is modified with a heel lift.  Walking casts are traditionally very low in the heel.  If a walking cast is used to treat peroneal tendonitis without a heel lift, the low position of the heel may actually contribute to the symptoms of peroneal tendonitis.

Brevis - meaning brief or short. Used to define the shorter of the two peroneal tendons.

Crepitus - a crackling sensation with motion.

Longus - the longer of the two peroneal tendons

Plantarflexion - the motion of the foot away from the shin. The combined peroneal tendons plantarflex the foot at the ankle during each cycle of gait.

The peroneal tendons originate high in the lateral aspect of the leg attaching to both the tibia and fibula. They descend the later compartment of the leg rounding the posterior aspect of the lateral malleolus (outside ankle bone) to continue down to the lateral side of the foot. The peroneus brevis inserts into the base of the fifth metatarsal. The peroneus longus curves under the midfoot to the bottom of the arch. Both the brevis and longus are innervated by the superficial peroneal nerve.

The peroneal muscles tendons have two functions;

• Their primary function is to stabilize the foot as the body passes over the foot. The peroneal tendons will help to stabilize the foot on uneven, rough surfaces. As the foot rolls from side to side, the peroneal tendons help to inhibit a lateral ankle sprain by preventing the foot from rolling to the outside (lateral side) of the foot
• The secondary function of the peroneal is to assist the calf with plantarflexion.

The peroneal muscles and tendons will be active in the gait cycle beginning in mid stance (to stabilize the foot) through toe off (to help the calf with plantarflexion). The antagonist of the peroneus brevis is the tibialis posterior.  The antagonist of the peroneus longus is the tibialis anterior.

Peroneal tendonitis is usually specific to the peroneus brevis tendon. Pain is most commonly found at the insertion of the tendon at the base of the 5th metatarsal. Pain is usually insidious in onset. Pain normally begins with the start of an activity that tends to warm up and subside as the activity progresses. Peroneal tendonitis does not normally cause swelling or redness.

Arthritis

Cuboid syndrome

Gout

Metatarsal fracture

Peroneal tendon rupture

Sinus tarsi syndrome

• Peroneal Tendon Subluxation

• Peroneal Tendon Rupture

• Cuboid Syndrome

• Sinus Tarsi Syndrome

• Ankle Pain

This article was written by Jeffrey A. Oster, DPM and last updated 4/5/10. No additional information is available for this topic.