eMedicine Specialties > Orthopedic Surgery > Foot & Ankle

Peroneal Tendon Pathology

Author: Kurtis Hort, MD, Foot and Ankle Surgery Fellow, Department of Orthopedic Surgery, Orthopaedic Associates of St. Augustine, Florida
Coauthor(s): James K DeOrio, MD, Director of Foot and Ankle Fellowship Program, Assistant Professor of Orthopedic Surgery, Orthopedic Surgery, St. Luke's Hospital, Jacksonville, Florida
Contributor Information and Disclosures

Updated: Mar 27, 2008

Introduction

History of the Procedure

Disorders of the peroneal tendons have been reported infrequently. Monteggia described peroneal tendon subluxation in 1803,¹ and this entity seems to be more commonly encountered than are disruptions of the peroneus longus or brevis alone. Nonetheless, peroneus brevis disorders have been described more often in the literature, with peroneus longus problems gaining more recent attention. However, much of the literature regarding both tendons is in the form of case reports.

Problem

A sesamoid bone called the os peroneum may be present within the peroneus longus tendon at about the level of the calcaneocuboid joint. The frequency with which an os peroneum occurs is controversial, with many supporting the idea that one is always present. However, the os peroneum may be ossified in only 20% of the population. The peroneus longus serves to plantar flex the first ray, evert the foot, and plantar flex the ankle.

The peroneus brevis originates from the fibula in the middle third of the leg. Its tendon courses anterior to the peroneus longus tendon at the ankle. It courses over the peroneal tubercle and inserts onto the base of the fifth metatarsal. The peroneus brevis everts and plantar flexes the foot.

The peroneal tendons share a common tendon sheath proximal to the distal tip of the fibula. More distally, each tendon is housed within its own sheath. The common sheath is contained within a sulcus on the posterolateral aspect of the fibula, which prevents subluxation. The primary restraint to tendon subluxation is the superior peroneal retinaculum (SPR). This fibrous band originates on the posterolateral aspect of the fibula and inserts onto the calcaneus. It is reported to average 10-20 mm in width and to course in a posteroinferior direction, although variants are not uncommon.

Problems may arise in either of the tendons alone, or both may be involved with subluxation. The hallmark of disorders of the peroneal tendons is laterally based ankle or foot pain. Whether the problem is tendinous degeneration or subluxation, the clinical manifestation is pain. With time, loss of eversion strength may occur.

Problems arising with the peroneus longus include tenosynovitis and tendinous disruption (acute or chronic). The os peroneum may be involved with the degenerative process or as a singular disorder and can be fractured or fragmented. Longitudinal tears of the peroneus longus are uncommon but have been reported.²

Longitudinal tears of the tendon are the most common problem seen with the peroneus brevis tendon. These may be single or multiple. Tendinitis and tenosynovitis also may occur.

Subluxation of both peroneal tendons may occur following an acute traumatic episode or may be of a more chronic nature.

Related eMedicine topics:
Ankle, Tibialis Posterior Tendon Injuries
Peroneal Mononeuropathy
Peroneal Tendon Syndromes

Related Medscape topics:
Resource Center Arthritis
Specialty Site Orthopaedics
Evans procedure with peroneus brevis tendon transfer.

Frequency

Disorders of the peroneal tendons are less common than other tendon problems involving the Achilles or posterior tibial tendons. However, it is impossible to estimate their true frequency in the United States or abroad.

Etiology

The precise etiology of peroneal tendon disorders depends somewhat on the specific problem being addressed. All disorders may result following a traumatic episode, direct or indirect, with a lateral ankle sprain being the most common trauma. Brandes and Smith have reported that 82% of patients with primary peroneus longus tendinopathy had a cavo-varus hindfoot.³ The presence of an os peroneum also has been postulated to predispose to peroneus longus rupture. Ruptures likewise have been reported to occur secondary to rheumatoid arthritis and psoriasis, as well as diabetic neuropathy, hyperparathyroidism, and local steroid injection.^4,5,6

Longitudinal splits in the peroneus brevis tendon appear to result from mechanical factors. Repetitive or acute trauma causes the attritional ruptures. These ruptures may result from an incompetent superior peroneal retinaculum that allows the peroneus brevis to rub abnormally against the fibula.

Overcrowding from a peroneus quartus muscle also has been reported. The blood supply to the tendon has been shown to be adequate.

Subluxation of the peroneal tendons results from disruption of the superior peroneal retinaculum and usually involves avulsion of the retinaculum from its fibular insertion. The mechanism of injury typically involves an inversion injury to the dorsiflexed ankle with concomitant forceful contraction of the peroneals. Some patients have a more chronic presentation and cannot recall a traumatic episode. Congenital dislocations also have been reported. An inadequate groove for the peroneals in the posterolateral fibula may be a cause of subluxation as well.

Pathology of the longus and brevis tendons almost always occurs concurrently. Brandes and Smith noted a 33% incidence of concomitant problems.³

Pathophysiology

Brandes and Smith have described and classified primary peroneus longus tendinopathy.³ They present 3 anatomic zones in which the tendon can be injured. Zone A is the level of the superior peroneal retinaculum. Zone B is the level of the inferior peroneal retinaculum. Zone C is the level of the cuboid notch. In their series, complete ruptures were most likely in zone C, while partial ruptures were more common in zone B. In the same study, surgical findings were classified into 3 groups. Group I pathology had no frank rupture but did have adhesions or thickening of the tendon. Group II pathology consisted of partial tears with some continuity of the tendon. Group III had complete ruptures with complete loss of continuity. All group III pathology occurred in zone C.

Other attempts have been made to classify peroneal tendon pathology. Sobel et al have presented a classification for tears of the peroneus brevis tendon as follows:^7,8

• Grade 1 - Flattened tendon
• Grade 2 - Partial-thickness split less than 1 cm in length
• Grade 3 - Full-thickness split less than 2 cm in length
• Grade 4 - Full-thickness split more than 2 cm in length

Eckert and Davis have classified superior peroneal retinaculum (SPR) pathology as follows:⁹

• Grade I - SPR elevated from fibula
• Grade II - Fibrocartilaginous ridge elevated from fibula with SPR
• Grade III - Cortical fragment avulsed with SPR

Presentation

The patient with peroneal tendon pathology typically complains of laterally based ankle or hindfoot pain. The pain usually worsens with activity. However, presentation and diagnosis often are delayed. Patients may or may not recall a specific episode of trauma. Brandes and Smith reported that only 9 of 22 patients with primary peroneus longus tendinopathy recalled an inciting event and that the event was an average of 4.3 months prior to presentation.³

Peroneal tendon subluxation or dislocation may present acutely following a traumatic injury to the ankle. However, it is not uncommon for these to present later with an uncertain history of trauma. Patients also may complain of snapping or popping in the ankle.

On physical examination, there usually is tenderness to palpation along the course of the peroneal tendons. Edema also may be present. These disorders require a high level of suspicion. Even frank dislocations may be missed if not specifically evaluated.

A provocative test for peroneal pathology has been described. The patient's foot is examined hanging in a relaxed position with the knee flexed 90^º. Slight pressure is applied to the peroneal tendons posterior to the fibula. The patient is then asked to forcibly dorsiflex and evert the foot. Pain may be elicited, or the tendons may be felt to sublux.

Indications

The primary indication for treating these disorders is pain. Nonsurgical treatment usually is attempted first. Failure of conservative measures is an indication for operative intervention.

Relevant Anatomy

See Problem.

Contraindications

The only true contraindication to surgery is inability to tolerate surgery for another medical reason. Because the surgery can be performed under regional anesthesia, this is rarely the case.

Age is not a contraindication, as even elderly patients who place low demands on these tendons may experience significant pain relief following surgery.

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