Peroneal Tendon Repair

Why this approach — at MOS

Peroneal tendon pathology is one of the most consistently underdiagnosed causes of chronic lateral ankle pain. I see patients regularly who have been treated for "ankle sprains" for months when the actual problem is a peroneus brevis tear visible on MRI. Physical examination clues — pain directly over the peroneal tendons posterior to the fibula, rather than at the ATFL ligament anterior to it — help differentiate the diagnosis. I confirm every case with MRI before recommending surgery.

When both peroneal tendon pathology and lateral ankle instability are present, I address both at the same operation. The Broström-Gould ATFL repair through the anterior incision and the peroneal tendon repair through the posterior incision can be performed sequentially. Treating both problems in one anesthetic is more efficient for the patient and avoids two separate recovery periods.

For the peroneus brevis repair, I make a judgment call on tissue quality intraoperatively. A reasonable-looking tendon with a cleanly split tear is tubularized — the results are good. A severely degenerated tendon with minimal viable tissue is better treated by tenodesis to the peroneus longus. Over-repairing poor tissue leads to re-tear. Patients across the Germantown and Montgomery County area who present with both problems benefit from a surgeon who can address both at one sitting.

Who is a candidate?

Indications

• Symptomatic peroneal tendon tear confirmed on MRI with persistent lateral ankle pain and weakness unresponsive to conservative treatment
• Peroneal tendon subluxation (tendon snapping or dislocating over the fibula) causing mechanical symptoms and functional impairment
• Peroneus brevis longitudinal split tear involving more than 50% of the tendon cross-section (smaller tears are managed non-operatively longer)
• Concurrent lateral ankle instability with the peroneal tear — both can be addressed in one procedure
• Peroneal tendon subluxation in an athlete who cannot afford episodes of tendon dislocation during competition

Contraindications

• Mild partial tear (<50%) responding to activity modification, physical therapy, and bracing — surgery is not necessary for well-compensated partial tears
• Active ankle infection
• Peripheral vascular disease compromising wound healing

Conservative Treatment First

Non-surgical treatment is appropriate for partial peroneal tendon tears and peroneal tendinopathy. Relative rest and activity modification reduce tendon load during the acute phase. A lace-up ankle brace or rigid stirrup brace provides lateral support and prevents the inversion stress that loads the peroneal tendons. Physical therapy targeting peroneal strengthening, proprioception training, and eccentric loading exercises can improve tendon health and symptoms over 6–12 weeks.

A corticosteroid injection in the peroneal tendon sheath can reduce tenosynovitis and is used diagnostically as well — temporary relief confirms the peroneal tendons as the pain source. Steroid injections must be used sparingly because they can weaken tendon tissue and risk rupture with repeat injections.

Surgery is offered when a thorough conservative trial has failed and MRI confirms a significant structural tear causing persistent symptoms.

The procedure

What Is Peroneal Tendon Repair?

Peroneal tendon repair is surgery to fix torn or dislocating peroneal tendons on the outer side of the ankle. The most common injury is a longitudinal split tear of the peroneus brevis tendon. Surgery trims, tubularizes, and repairs the tendon and, when the tendon has been dislocating, repairs the superior peroneal retinaculum that keeps the tendons in their groove behind the fibula.

The peroneal tendons are two tendons — the peroneus brevis and peroneus longus — that run behind the fibula (outer ankle bone), through a fibrocartilaginous groove, and into the foot. The peroneus brevis inserts at the base of the fifth metatarsal and is the primary lateral stabilizer of the ankle. The peroneus longus runs under the foot to the first metatarsal and is important for plantarflexion of the first ray. Both tendons are held in the fibular groove by the superior peroneal retinaculum (SPR), a fibrous band that acts as a restraint.

Peroneal tendon pathology frequently coexists with chronic lateral ankle instability (the same ankle inversion sprains that stretch the ATFL and CFL also stress the peroneal tendons and SPR). Patients with peroneal tendon tears often present with persistent lateral ankle pain that has been attributed to ankle sprains for months or years, with the tendon pathology going unrecognized until MRI is obtained.

Peroneus brevis longitudinal split tear is the most common peroneal tendon injury. The tendon splits lengthwise — often developing a C-shaped or U-shaped configuration as it wraps around the peroneus longus. The split is repaired by debridement of non-viable tissue and tubularization (sewing the viable edges together to restore a round tendon cross-section).

Peroneal tendon subluxation occurs when the SPR is torn or lax, allowing one or both tendons to dislocate anteriorly over the fibula during ankle movement. Repair includes restoring the SPR and often deepening the fibular groove.

Peroneus longus tears are less common, most often occurring at the cuboid tunnel on the plantar foot, and are managed based on tear extent and patient symptoms.

What Happens During Peroneal Tendon Repair?

Surgery is performed at an ambulatory surgery center as an outpatient procedure.

Anesthesia: A popliteal sciatic nerve block provides anesthesia for the posterior ankle and lateral foot. Sedation or general anesthesia is added per patient preference. The block provides post-operative pain control for 12–18 hours.

Positioning: The patient lies on their side (lateral decubitus) with the operative ankle on top, or supine with the leg rotated inward. A tourniquet on the calf controls bleeding.

Incision: A curved incision is made along the posterior fibula, following the course of the peroneal tendons from behind the fibula to the fifth metatarsal base. The sural nerve, which runs adjacent, is identified and protected.

Tendon sheath opening and exploration: The peroneal tendon sheath is opened longitudinally. Both tendons are inspected for tears, degeneration, and position. Chronic tenosynovitis (inflamed, thickened tendon sheath) is debrided.

Peroneus brevis repair (tubularization): The split tear is assessed. Non-viable, frayed tissue is sharply debrided. If the remaining tendon cross-section is adequate (greater than 50% of normal), the split edges are approximated with a running suture, restoring the tendon to a tubular shape. For tears involving more than 75% of the tendon cross-section with poor tissue quality, tenodesis to the peroneus longus may be performed (the small remnant of the brevis is attached to the longus).

Superior peroneal retinaculum repair: If the SPR is torn or lax, it is repaired back to the fibular periosteum using sutures, tightening the restraint over the tendons. The fibular groove is deepened with a burr if it is shallow (groove deepening), creating a better mechanical restraint against future dislocation.

Combined Broström procedure: If lateral ankle ligament instability coexists — as it frequently does — the Broström-Gould ATFL and CFL repair is performed through an additional incision just anterior to the fibula at the same operative sitting.

Closure: The tendon sheath is closed. Layered wound closure. Posterior splint in neutral ankle position.

Recovery timeline

Frequently Asked Questions