Monday, May 6, 2013

Overview of Peroneal Tendon Issues

Many patients that we treat at our office have chronic ankle instability in the form of lateral tendon dislcocations, or chronic ankle sprains. Many times these patients are unclear as to how important these tendons are to the overal stability and function of the ankle joint. With abnormal tendon gliding and ligamentous attenuations and ruptures, these tendons may also become painful with patients who have chronic ankle sprains. This is a comprehensive overview of this pathology and treatment options to help out with the understanding of these clinical scenarios.

History of the Procedure
Disorders of the peroneal tendons have been reported infrequently. Monteggia described peroneal tendon subluxation in 1803, 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.

The peroneal muscles make up the lateral compartment of the leg and receive innervation from the superficial peroneal nerve. The peroneus longus muscle originates from the lateral condyle of the tibia and the head of the fibula. The tendon of peroneus longus courses behind the peroneus brevis tendon at the level of the ankle joint, travels inferior to the peroneal tubercle, and turns sharply in a medial direction at the cuboid bone. The tendon inserts into the lateral aspect of the plantar first metatarsal and medial cuneiform.
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.

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.
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.

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.

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.

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.

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 90ยบ. 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.

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.

Operative Considerations

With physical therapy, MRI, and need for primary or secondary repair will be determined based on overal health of the patient, as well as how effective nonsurgical measures have been. If the pain and resolution is not fully noted through physical therapy and bracing one should consider the possiblity of repair. If there are tendon tears associated with the pathology, repair is recommended. If an associated low muscle (peroneus quartius) or ruptured retinaculum is identified, repair is also likely required. We are experts in this pathology, and treat this regularly, and I feel a proper evaluation for this condition will be beneficial to anyone with recurrent ankle sprains, as well as pain in the lateral ankle.

Hammer Toes

Hammertoes occur when the smaller toes of the foot become bent and prominent. The four smaller toes of the foot are much like the same fingers in the hand. Each has three bones (phalanges) which have joints between them (interphalangeal joints). The toes form a joint with the long bones of the foot (metatarsals) and it is this area that is often referred to as the ball of the foot.
Normally, these bones and joints are straight. A hammertoe occurs when the toes become bent at the first interphalangeal joint, making the toe prominent. This can affect any number of the lesser toes. In some cases, a bursa (rather like a deep blister) is formed over the joint and this can become inflamed (bursitis). With time, hard skin (callous) or corns (condensed areas of callous) can form over the joints or at the tip of the toe.

What causes hammertoes?
There are many different causes but commonly it is due to shoes or the way in which the foot works (functions) during walking. If the foot is too mobile and / or the tendons that control toe movement are over active, this causes increased pull on the toes which may result in deformity.
In some instances trauma (either direct injury or overuse from walking or sport) can predispose to hammertoes. Patients who have other conditions such as diabetes, rheumatoid arthritis and neuromuscular conditions are more likely to develop hammertoes.

Are women more likely to get the problem?
It is more common in women as they tend to wear tighter, narrower shoes with increased heel height. These shoes place a lot of pressure onto the joint and predispose to deformity. It is common for patients to wear shoes that are too small and this can predispose to the problem. In a study we have performed, 95% of patients were in the wrong size shoes.

Will it get worse?
At the start of the deformity, it is generally mobile which means that the toe can be straightened. However, with time, the joint become fixed or rigid. This can then affect the joint at the ball of the foot and, in severe cases, the joint capsule ruptures (tears) so that the joint becomes dislocated and the toe sits up in the air.

What are the common symptoms?
Deformity / prominence of toe
Redness around the joints
Swelling around the joints
Corn / Callous
Difficulty in shoes with deformity of the shoe upper
Difficulty in walking
Stiffness in the joints of the toe

How is it identified?

Clinical examination and a detailed history allow diagnosis. X-rays are often not required but can help to evaluate the extent of the deformity and the degree of arthritis within the joint.

What can I do to reduce the pain?
There are several things that you can do to try and relieve your symptoms:
Wear good fitting shoes with a deep toe box
Avoid high heels
Use a toe prop to straighten the toe if it is still mobile
Wear a protective pad over the toe
See a doctor at the Family Foot and Leg Center.

What can we as a specialist do to correct or reduce your symptoms?
If simple measures do not reduce your symptoms, there are other options:
Advise appropriate shoes
Advise exercises if the toes are still mobile
Show you how to strap the toe in a corrected position
Provide a splint or protection
Consider orthotics

Advise on surgery
The way in which your foot loads during walking can place increased stress on the ball of the foot and cause increased toe activity. Special shoe inserts (orthoses) can help to control foot movement. Whilst these are unlikely to resolve established deformity they may help reduce discomfort in the ball of the foot.

Will this cure the problem?
If the deformity is mobile, then this may help prevent progression although there have been no scientific studies to analyse the benefit. If the deformity is fixed, then orthotics will not cure the problem but may reduce the associated symptoms.

What will happen if I leave this alone?
Generally, the deformity becomes worse with time and slowly becomes fixed (stiff). This can cause discomfort in shoes. The position of the toe places increased stress on the ball of the foot and this can become painful. Corn and callous formation on the ball of the foot is not uncommon. In some cases, the metatarsophalangeal joint capsule ruptures, causing the toe to sit up in the air.

Can the deformity be reversed or cured?
The only effective way of correcting the deformity is to have an operation.

How does the operation correct the deformity?
There are a number of different operations. However, the most common operations are:
Tendon transfer
Digital arthroplasty
Digital arthrodesis

Hopefully this is an effective run down of various questions commonly asked by my patients here, and if you come up with more please comment and the questions will be answered.