Peroneal Tendon Pathology Treatment & Management

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.

The only true contraindication for surgical treatment is inability to tolerate surgery for another medical reason. Because the operation can be performed under regional anesthesia, such inability is rare. Age is not a contraindication; even elderly patients who place low demands on these tendons may experience significant pain relief following surgery.

The decision to use a specific procedure depends on the specific pathology present and on good surgical judgment. The effectiveness of nonoperative versus operative treatment may be debated, though the current evidence favors surgical treatment of tendon dislocation. Magnetic resonance imaging (MRI) has emerged as an extremely valuable evaluation tool in this setting, and ultrasonography (US) is increasingly used.

The need to proceed to surgery is always controversial. Peroneal tendoscopy as a diagnostic and therapeutic tool has lacked support from level I and II studies. The role of platelet-rich plasma (PRP) in the treatment of peroneal tendon pathologies remains to be defined.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are often given to reduce pain and inflammation. Any underlying medical problem (eg, diabetes, rheumatoid arthritis) should be medically controlled. ^[31]

After medical therapy is initiated, nonoperative treatment usually is attempted. In general, conservative therapy may include the following:

• Activity modification
• Footwear changes
• Temporary immobilization
• Corticosteroid injection ^{[32, 33]}

Lateral heel wedges can take stress off of the peroneal tendons to allow healing. Nonoperative treatment of tenosynovitis alone often is successful, whereas a complete or partial tendon rupture often leads to surgery. Likewise, an acute injury is more likely to respond to conservative care than is a chronic process. Several authors have reported a high percentage of patients with tendon ruptures or subluxation that eventually require surgery.

As with other disorders of the foot and ankle, the use of corticosteroid injection must be undertaken with extreme caution to avoid iatrogenic rupture.

Surgical treatment is best considered in the context of the specific pathology being addressed. ^[34] With any procedure, it is important to remove abnormal-appearing synovium or tenosynovium, which can cause persistent pain if not removed. This can be accomplished easily with the use of a rongeur. (See the images below.)

Torn or degenerated tendons or ganglia removed from peroneal tendons can show a myxoid pattern of degeneration (see the images below).

Tenosynovitis

Tenosynovitis may be treated surgically with simple division of the tendon sheath. Coughlin's description of the procedure is as follows. ^{[35, 36]}

A tourniquet is used. The tendons are exposed through an incision that curves from the posterior aspect of the fibula toward the base of the fifth metatarsal. Care must be taken to protect the sural nerve. The tendon sheath is opened longitudinally, and each tendon is examined. Any degenerated area of tendon generally is removed. A peroneus quartus can be excised. If the peroneal tubercle is proud, it may be smoothed or leveled. The tendon sheath is left unrepaired.

Postoperatively, the patient is placed in a short leg cast. Weightbearing in the cast may begin after 2 weeks. Range of motion (ROM) and strengthening are started after casting is discontinued at 4 weeks.

Primary peroneus longus tendinopathy

This disorder may be approached in a manner similar to that described above with subsequent debridement of the tendon, release of the inferior peroneal retinaculum (IPR), and smoothing of the peroneal tubercle. Brandes and Smith advocated adding a lateral closing wedge calcaneal osteotomy (Dwyer) if the patient has a cavus or varus deformity of the hindfoot. ^{[5, 37]}

Postoperatively, a short leg cast may be used for up to 6 weeks to allow for the osteotomy to heal. Weightbearing in a protective boot is recommended for an additional 6 weeks.

Os peroneum excision

If symptoms are directly referable to the os peroneum by reason of fracture or fragmentation, it may simply be excised as follows.

The inferior portion of the typical peroneal tendon approach is used. With pathology limited to the os peroneum, this may consist only of the portion of the incision from the tip of the fibula to the base of the fifth metatarsal. The tendon sheath is incised, and the os is sharply removed by "shelling out" the ossified fragment from the tendon.

The tendon may be repaired with interrupted absorbable or nylon suture if only a longitudinal defect is present. If the tendon has lost continuity, it may be repaired with a modified Kessler or similar stitch or tenodesed to the intact peroneus brevis tendon.

Postoperatively, a short leg cast is applied for a total of 6 weeks, with weightbearing beginning after 3-4 weeks. A removable boot then is used for an additional 4 weeks, with normal footwear to follow. Activity is advanced to tolerance after boot removal.

Peroneus brevis repair

The patient is placed supine with a sandbag under the ipsilateral hip. A thigh-high tourniquet is used. A curved longitudinal incision along the course of the peroneal tendons is extended from several centimeters above the lateral malleolus to the base of the fifth metatarsal. The superior peroneal retinaculum (SPR) is incised sharply, with a small tag left on the fibula for later repair. The tendons are inspected. The peroneus brevis will lie closer to the fibula.

If a single longitudinal tear is noted, it may be simply repaired with a running coated polyester suture (eg, Ethibond Excel; Ethicon, New Brunswick, NJ. If the tendon split represents less than 30% of the normal tendon width, the smaller section may be excised. If a peroneus quartus muscle is encountered, it may simply be resected. If multiple degenerative tears are present, they are debrided with an eventual attempt to tubularize the remaining tendon. Coughlin and Mann recommended tenodesis to the peroneus longus if less than one third of the tendon remains. ^[35]

After tendon pathology is addressed, the SPR is repaired over the tendons. The skin is closed in a routine fashion.

Postoperatively, a short leg cast is applied for 6 weeks, with weightbearing started after 4 weeks. A boot is then used for an additional 4 weeks with daily ROM exercises.

Peroneal tendon subluxation

Surgical treatment often is necessary to correct subluxing or dislocating peroneal tendons. If the problem is diagnosed early, acute repair of the peroneal retinaculum may be undertaken, though most often, intervention occurs later. ^{[38, 39, 40, 41, 42, 43]}

Mak et al reported that for patients with fractures of the calcaneus in association with dislocation of the peroneal tendon, use of an anterior incision to repair the peroneal tendon avoided problems associated with proximal extension of the vertical limb via a lateral extensile approach. ^[44] In a series of 14 patients, this approach proved technically effective and produced favorable outcomes.

Acute repair of superior peroneal retinaculum

A thigh tourniquet is used. The incision is in line with the peroneal tendons from 6 cm proximal to the tip of the fibula to 2 cm distal to it. The SPR is identified and sharply removed from the fibula 1 cm posterior to the fibula. A bony trough is then created on the posterolateral fibula parallel with the remaining edge of the retinaculum just posterior to it. This can be performed with an osteotome or with a burr.

Three or four drill holes then are created in the fibula along the trough. A polyester suture is used to approximate the retinaculum to the fibula by passing it through both of the holes and the retinaculum. The retinaculum is then further imbricated to the portion that is still attached to the fibula with an absorbable suture. The skin is closed in a routine manner.

If a large piece of the fibula has been avulsed, it may be internally fixed with a small fragment bone screw, making true repair of the retinaculum unnecessary.

Postoperatively, a short leg cast is applied for 6 weeks, with weightbearing allowed after 4 weeks.

Surgical options for chronic dislocation

Surgical options for chronic dislocation have been grouped into five broad categories (see below). ^{[45, 46]}  At present, insufficient high-quality data are available to establish which option or options are superior in this setting. ^[47]

Superior peroneal retinaculum repair

The direct retinacular repair is the most anatomic in nature and probably the easiest to perform with the least chance of complications. It is gaining popularity. The procedure is identical to the one described for acute repairs.

A knotless tendoscopic approach to SPR repair was described by Nishimura et al for recurrent peroneal tendon dislocation. ^[48]

Tissue transfer to reinforce superior peroneal retinaculum

Transfers have been described using the Achilles tendon, as well as the plantaris and peroneus brevis tendons. They all basically involve taking a strip of free tissue (eg, plantaris) or a strip of tendon in continuity (eg, tendo Achillis) and reconstructing a portion of the retinaculum to prevent subluxation. These procedures are mentioned only for completeness and are not currently recommended.

Tendon rerouting

The tendons may be rerouted beneath the calcaneofibular ligament. This procedure involves cutting the peroneal tendons with subsequent repair after rerouting. ^[49]  Occcasionally, the calcaneofibular ligament may be sharply released from its fibular origin and transferred superficially to augment SPR repair.  

Bone block procedures

Numerous bone block procedures have been described. They involve sagittal osteotomy of the fibula, whether partially or in whole, with posterior displacement or rotation of the more lateral fragment to serve as a mechanical block to prevent anterior subluxation of the tendons. Bone displacement usually is secured with screws.

Groove-deepening procedures

The patient is placed in a supine position with a bump under the ipsilateral hip. A thigh tourniquet is used. A 10-cm incision in line with the peroneal tendons is centered over the distal posterior border of the fibula. The SPR is incised, and the tendons are dislocated anteriorly and inspected.

A sharp osteotome is used to raise a bony flap from the posterolateral corner of the distal fibula that is approximately 3 cm long. Care is taken to keep the posteromedial border of the flap intact so that it may act as a hinge. A burr then is used to remove cancellous bone from beneath the flap in order to deepen the peroneal groove. The flap then is reduced and impacted with a bone tamp. A screw may be used for added stability. (See the image below.)

The SPR then is repaired, and the skin is closed in a routine fashion.

Postoperatively, a short leg nonweightbearing cast is applied for 2 weeks in a position of slight eversion and plantarflexion. After 2 weeks, sutures are removed, and the patient is placed in a removable boot or short leg cast in a more neutral position. Weightbearing to tolerance is allowed at that time. All immobilization is discontinued after 6 weeks.

Peroneal tendoscopic surgery

Several reports have confirmed peroneal tendoscopy as an effective treatment in improving functional outcome scores across a range of peroneal tendon pathologies. Even though the traditional open surgical techniques have shown good outcomes for a variety of peroneal tendon pathologies, these can lead to adhesions, postoperative stenosis, synovitis, tendon subluxation, and nerve damage.

Currently accepted indications for peroneal tendoscopy, in addition to its role as a diagnostic tool, include treatment of the following:

• Partial tears requiring debridement
• Snapping
• Peroneal tendon instability
• Tenosynovitis
• Postoperative adhesions and scarring

Tendoscopic intervention offers a minimally invasive surgical approach that can potentially minimize the risk of these complications and has several advantages over traditional open procedures, including shorter hospital stays, reduced cost, improved cosmesis, reduced morbidity and postoperative pain, and earlier recovery. ^{[50, 51, 52]}  Level IV and V studies on peroneal tendoscopy have generally reported it to be safe and effective.

Rehabilitation

The clinical success of surgical treatment of peroneal tendon tears and ruptures is largely dependent on appropriately directed rehabilitation. For optimal outcomes, the rehabilitation protocol must be adjusted to each patient on an individual basis. Currently, there is a trend toward a shorter immobilization time and early ROM, though there is no consensus in the literature on best-practice recommendations for optimizing rehabilitation after surgical treatment of peroneal tendon tears or ruptures. ^[53]

Recurrence of symptoms after surgical treatment is possible. Patients may complain of stiffness or tightness of the ankle after surgical repair. Surgical treatment also may be complicated by injury to the sural nerve or to the superficial peroneal nerve. The sural nerve may be more at risk because of its variable position. Infections may complicate any surgical procedure. The potential for blood clots or pulmonary embolus, while uncommon with foot and ankle surgery, must not be underestimated.