What are the peroneal tendons and why do they hurt?

The peroneal tendons run down the outer side of the lower leg and curve behind the outer ankle bone, helping to stabilize the ankle and turn the foot outward. They become irritated after ankle sprains or from overuse, causing pain and swelling behind and below the outer ankle bone that is worse with activity.

Could this be why my ankle still hurts after a sprain?

Quite possibly. Peroneal tendonitis frequently follows an ankle sprain, because the same outer-ankle structures are involved. Outer-ankle pain and swelling that linger after a sprain are a reason to look specifically at the peroneal tendons, which can be a hidden source of ongoing symptoms.

Usually not. Most peroneal tendonitis settles with relative rest, bracing or taping, physical therapy, and anti-inflammatory measures. Surgery is reserved for tendons that subluxate, repeatedly slipping out of position behind the bone, or that have torn and do not respond to conservative care.

What does a snapping feeling at the outer ankle mean?

A snapping or popping sensation behind the outer ankle bone can mean a peroneal tendon is slipping out of its normal groove, called subluxation. That pattern is worth evaluating, because tendons that repeatedly subluxate are the ones more likely to need surgical stabilization rather than conservative care alone.

Peroneal Tendonitis, Steven J. Lee, MD

Peroneal tendonitis is irritation of the peroneal tendons, two tendons that run down the outer side of the lower leg and curve behind the outer ankle bone (the lateral malleolus) on their way into the foot. They help stabilize the ankle and turn the foot outward, and they are commonly irritated after ankle sprains or from overuse.

It typically causes pain and swelling behind and below the outer ankle bone, worse with activity. Most cases respond well to conservative care. The cases that may need surgery are the ones where a tendon slips out of its normal position behind the bone (subluxation) or develops a tear.

Symptoms

Common findings include:

Pain and swelling behind and below the outer ankle bone
Pain that worsens with activity and eases with rest
Tenderness along the tendons on the outer ankle
A snapping or popping sensation if a tendon is slipping out of place

Often follows a sprain

Peroneal tendonitis frequently appears after an ankle sprain or in an ankle that keeps rolling, because the same outer-ankle structures are involved. Outer-ankle pain that lingers after a sprain is a reason to look specifically at the peroneal tendons, since they can be a hidden source of ongoing symptoms.

How it is diagnosed

The diagnosis is mainly clinical, based on tenderness along the tendons and pain when the foot is turned outward against resistance. Ultrasound or MRI is used when a tear or tendon subluxation is suspected, or when symptoms do not settle with conservative care.

Dr. Lee's approach

Dr. Lee treats peroneal tendonitis conservatively first. That means relative rest from aggravating activity, bracing or taping to support the outer ankle, physical therapy to strengthen and rebalance the tendons, and anti-inflammatory measures to settle the irritation. Most cases improve with a genuine course of this care.

Surgery is reserved for the specific situations that do not respond to conservative care: a tendon that subluxates, repeatedly slipping out of position behind the bone, or a tendon that has torn. In those cases the tendon is repaired and stabilized so it tracks properly again. Because outer-ankle pain often follows a sprain, any associated ankle instability is addressed as well.

Non-surgical treatment

Most cases respond to conservative care:

Relative rest from the activity that aggravates it
Bracing or taping to support the outer ankle
Physical therapy to strengthen and rebalance the tendons
Anti-inflammatory measures to settle the irritation

Surgical treatment

Tendons that subluxate, slipping out of their groove behind the outer ankle bone, or that have torn, may need surgery when conservative care does not resolve them. The procedure repairs the torn tendon and stabilizes it so it tracks properly behind the bone, and any associated ankle instability is addressed at the same time.

Recovery timeline

Recovery depends on whether surgery is needed:

Non-surgical
Relative rest, bracing or taping, and therapy over several weeks, with most cases improving in that window.
After surgery, weeks 0 to 6
Protected immobilization while the repaired and stabilized tendon heals.
Months 2 to 4
Progressive strengthening and a graded return to running and cutting activity.

What patients commonly misunderstand

Two things to keep in view:

Lingering outer-ankle pain after a sprain may be the tendons. Peroneal tendonitis often follows an ankle sprain. Outer-ankle pain and swelling that persist after a sprain are a reason to look specifically at the peroneal tendons rather than assuming it is just a slow-healing sprain.
Most cases do not need surgery. The large majority of peroneal tendonitis settles with relative rest, bracing or taping, therapy, and anti-inflammatory measures. Surgery is reserved for tendons that slip out of position or tear and do not respond to that care.

This page is general educational content authored by Dr. Lee. It is not a substitute for individual medical advice. Every patient's case is different, book a consultation to discuss yours.

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Outer-ankle pain and swelling, especially after a sprain? The peroneal tendons are worth a look.

Peroneal tendonitis causes outer-ankle pain and swelling, often after a sprain or from overuse. The large majority settle with relative rest, bracing or taping, physical therapy, and anti-inflammatory measures. Tendons that slip out of position or tear may need surgical repair and stabilization.

Peroneal Tendonitis: outer-ankle pain from the tendons behind the bone.