Peroneal Tendon Pathology


Background

Disorders of the peroneal tendons are often overlooked as causes of lateral ankle pain and have been reported infrequently. These injuries may go unrecognized or may be misdiagnosed as ankle sprains. The three major pathologies of the peroneal tendons include the following:

  • Tenosynovitis and tendinitis
  • Peroneal tendon instability (subluxation and dislocation)
  • Peroneal tendon tear or rupture

Monteggia described peroneal tendon subluxation in 1803, [1and 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.

For patient education resources, see Ankle Sprain.

Anatomy

The peroneal muscles make up the lateral compartment of the leg and are innervated by the superficial peroneal nerve. The peroneus longus originates from the lateral condyle of the tibia and the head of the fibula. The tendon of the peroneus longus courses posterior to the peroneus brevis tendon at the level of the ankle joint, travels inferior to the peroneal tubercle, turns sharply in a medial direction just plantar to the cuboid bone (through the cuboid tunnel), and inserts into the lateral aspect of the plantar first metatarsal and the medial cuneiform. (See the image below.)

Peroneus longus tendon next to peroneus brevis tenPeroneus longus tendon next to peroneus brevis tendon.

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 plantarflex the first ray, evert the foot, and plantarflex the ankle.

The peroneus brevis originates from the fibula in the middle third of the leg. Its tendon is 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 plantarflexes 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 retromalleolar sulcus/groove is 6-7 mm wide and 2-4 mm deep and is lined by fibrocartilage to allow smooth gliding of the tendons. The sulcus is concave in 82% of cases, flat in 11%, and convex in 7%. A rim of fibrocartilage is often present at the lateral border of fibula, adding 2-4 mm to the depth of the groove.

At the level of the retromalleolar sulcus is the superior peroneal retinaculum (SPR).  The calcaneofibular ligament lies deep to the peroneal tendons just distal to the sulcus. The calcaneofibular ligament helps stabilize the peroneal tendons and is oriented in much the same direction as the SPR. Therefore, inversion injuries that damage the calcaneofibular ligament can also result in injury to the SPR. More distally (inferiorly), the tendons are restrained by the inferior peroneal retinaculum (IPR).

The SPR is the primary restraint to tendon subluxation. This fibrous band originates on the posterolateral aspect of the fibula and inserts onto the lateral wall of the calcaneus. It is reported to average 10-20 mm in width and to course in a posteroinferior direction, though variants are not uncommon.

Pathophysiology

Problems may arise in an individual peroneal tendon, or both may be involved. The hallmark of peroneal tendon disorders 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. Patients may also notice a popping or clicking that accompanies pain in the setting of subluxation or dislocation.

Problems arising with the peroneus longus include tenosynovitis and tendinous disruption (acute or chronic). The os peroneum may be involved with the degenerative process. Alternatively, the os peroneum may be fractured or fragmented acutely. 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 tears may be single or multiple. Tendinitis and tenosynovitis also may occur.

Subluxation of both peroneal tendons may occur after an acute traumatic episode or may be associated with more chronic disease. Chronic changes may also occur at the muscle. A comparison of the muscles attached to normal and torn peroneus brevis tendons demonstrated increased fatty degeneration at the muscle. [3The scoring system developed by Goutallier for the rotator cuff has been extrapolated to the peroneus brevis, but the impact of these findings remains to be seen. 

Brandes and Smith described and classified primary peroneus longus tendinopathy, [4specifying the following three anatomic zones in which the tendon can be injured:

  • Zone A - The level of the SPR
  • Zone B - The level of the IPR
  • Zone C - The level of the cuboid notch

In their series, complete ruptures were most likely in zone C, whereas partial ruptures were more common in zone B. [4In the same study, surgical findings were classified into three groups, as follows:

  • 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 presented a classification for tears of the peroneus brevis tendon that divides these injuries into the following four grades [56:

  • 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 classified SPR pathology as follows [7:

  • Grade I - SPR elevated from fibula
  • Grade II - Fibrocartilaginous ridge elevated from fibula with SPR
  • Grade III - Cortical fragment avulsed with SPR ("fleck" sign)
  • Grade IV (later added by Oden [8) - Posterior injury with dislocation of the tendon(s) superficial to the SPR

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. Severe calcaneal fractures with lateral displacement of the calcaneus can also result in the dislocation of the peroneal tendons. Forceful dorsiflexion of the foot with the peroneal muscles strongly contracted, as happens with a forward fall during skiing or springboard diving, can result in acute subluxation or dislocation of the peroneal tendons.

Brandes and Smith reported that 82% of patients with primary peroneus longus tendinopathy had a cavovarus hindfoot. [4The 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, hypothyroidism, foot and ankle fractures, tophaceous gout, fluoroquinolone use, and local steroid injection. [91011]

A hypertrophied peroneal tubercle that increses mechanical stresses on the peroneal tendons and interferes with normal gliding within the tendon sheaths can also predispose to peroneal tendon attrition and rupture. Irregularities of the retromalleolar groove can result in peroneal tendon tears as well.

Longitudinal splits in the peroneus brevis tendon appear to result from mechanical factors. In rare instances, repetitive or acute trauma may cause transverse ruptures. These ruptures may result from an incompetent SPR that allows the peroneus brevis to rub abnormally against the fibula.

Overcrowding from a peroneus quartus muscle, peroneal tenosynovitis, or a low-lying muscle belly of the peroneus brevis also has been reported as a cause of tendon ruptures. The blood supply to the tendon has been controversial, with cases for both tenuous and adequate blood supply having been put forth by various authors; at present, the issue remains undecided.

Tenosynovitis and tendinitis of the peroneal tendons are common among runners and ballet dancers and may occur in more than 75% of patients with chronic lateral ankle instability.

Subluxation of the peroneal tendons results from disruption of the SPR 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, though the extent of disease at each tendon typically varies. Brandes and Smith noted a 33% incidence of peroneus longus tendon tears in cases with peroneus brevis tendon tears. [4]

Epidemiology

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.

Prognosis

Outcome assessment after surgical treatment of peroneal tendon pathology is difficult. Much of the literature is in the form of case reports, with few large series in existence. Additionally, with the large variability in treatment, conclusions are hard to draw. Much of the decision-making in this area is based on surgeon experience.

Sammarco reported 10 of 13 patients with good or excellent results using varied surgical treatments of peroneus longus problems. [12Eight of those patients also had associated peroneus brevis pathology. Thompson and Patterson reported on three of their patients with peroneus longus pathology who responded well to surgical debridement and tenodesis. [13]

Krause and Brodsky reviewed 20 cases of peroneus brevis tears and noted that good or excellent results can be expected with surgical treatment. [14]

Demetracopoulos et al conducted a review of long-term outcomes in 34 patients with peroneal tendon tears treated with debridement and primary repair. [15At the time of final follow-up, pain scores had improved from a mean of 39 before operation to a mean of 10 postoperatively. There was a significant increase in the Lower Extremity Functional Scale score, from a mean of 45 preoperatively to a mean of 71 postoperatively. Of the 18 patients who responded, 17 returned to full sporting activity without limitation. There were no reoperations or operative failures.

Subsequent data confirm good outcomes, high satisfaction, and a quick return to sports with surgical treatment of peroneal tendon dislocation. Rates of return to sports are significantly higher in patients treated with both groove deepening and SPR repair than in those treated with SPR repair alone. [16Whereas a redislocation rate of nearly 50% is reported with conservative treatment, the rate is lower than 1.5% at long-term follow-up after surgical treatment.

History

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 nine 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. [4]

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.

Physical Examination

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. (see the image below.)

Ganglion arising from peroneal tendon sheath as caGanglion arising from peroneal tendon sheath as cause of painful swelling. Left image shows palpable tender swelling behind lateral malleolus; center image shows ganglion as seen intraoperatively; right image is view after excision.

A provocative test for peroneal pathology has been described. The patient's foot is examined hanging in a relaxed position with the knee flexed 90º. 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 subluxation of the tendons may be felt.

Circumduction of the ankle may reveal dislocation of the tendons with dorsiflexion and eversion and relocation with inversion and plantarflexion. Chronic dislocation of the tendons may be associated with chronic swelling and a palpable ridge along the posterolateral fibula (the "secondary pseudogroove” of the lateral fibular cortex).

A complete examination of the ankle must always be performed to rule out pathologic conditions such as lateral ankle instability, syndesmotic injuries, and painful os trigonum, as well as fractures at the posterior process of the talus, the lateral process of the talus, the anterior process of the calcaneus, and the fifth metatarsal base.

Diagnostic Considerations

Differential diagnoses for peroneal tendon pathology include the following:

  • Lateral ankle instability
  • Syndesmotic injuries
  • Osteochondritis of talus
  • Painful os trigonum
  • Lateral ankle and foot fractures (see Physical Examination)
  • Retrocalcaneal bursitis


Laboratory Studies

Laboratory studies are infrequently used in evaluating a patient for peroneal tendon pathology. If infection is a consideration, a complete blood count (CBC) with differential, an erythrocyte sedimentation rate (ESR), and a C-reactive protein (CRP) level may be obtained. Likewise, if undiagnosed rheumatologic disease is suspected, screening laboratory tests may be indicated.

Imaging Studies

Plain radiography

Standard radiographs [17of the foot and ankle, including weightbearing anteroposterior (AP), lateral, and mortise views, are usually obtained first. These can reveal fractures, large osteochondral defects of the talus, spurring of the retrofibular groove, lateral ankle impingement, and hypertrophy of the peroneal tubercle. Acute injuries with avulsion of the superior peroneal retinaculum (SPR) insertion on the fibula may demonstrate a characteristic fleck sign. Dislocation of the peroneal tendons should be considered in talus and calcaneus fractures. [1819]

Plain radiographs are also used to assess the hindfoot for arthritis that may contribute to the pain. Stress radiographs can rule out the presence of ankle instability.

Although the tendons cannot be imaged directly by means of radiography, the presence of an os peroneum fracture or proximal migration of the os peroneum is suggestive of peroneus longus rupture.

The os peroneum is best visualized on the oblique radiograph of the foot; it is less well seen on the other standard foot films. The AP view of the foot can reveal a fracture of the base of the fifth metatarsal, suggesting avulsion of the peroneus brevis insertion. The Harris view may be useful for demonstrating an enlarged peroneal tubercle on the calcaneus. The Canale view is used for visualizing the talar neck.

Tenography

Tenography is infrequently used but may be of benefit if combined with anesthetic injection into the tendon sheath for diagnostic purposes. It has been shown to be useful for demonstrating peroneal tendon impingement in patients with lateral ankle pain after calcaneal fracture. [20]

Magnetic resonance imaging

Magnetic resonance imaging (MRI) has been the imaging modality of choice for the peroneal tendons. [212223 MRI features of normal variants and diseases of the peroneal tendons, as well as the SPR, have been very elegantly demonstrated. [24(See the images below.) Increased fluid within the tendon sheath, tenosynovitis, or the presence of scar tissue may be apparent on MRI. Dynamic MRI can detect dislocatable peroneal tendons.

Appearance of normal peroneal tendons on MRI. AxiaAppearance of normal peroneal tendons on MRI. Axial turbo spin-echo (TSE) T1-weighted image (left) shows peroneus brevis (short arrow). TSE proton density (PD)-weighted fat-suppressed (FS) image (center) shows peroneus longus (arrowhead). Sagittal TSE T2-weighted FS image (right) shows peroneus longus (arrowhead).
Axial turbo spin echo (TSE) T1-weighted and TSE T2Axial turbo spin echo (TSE) T1-weighted and TSE T2-weighted fat-suppressed (FS) MRI shows split of peroneus brevis tendon into two subtendons.

Longitudinal tears in the peroneus brevis have been readily identified on MRI. In addition, associated findings on MRI have been described for peroneus brevis tears. These include chevron-shaped tendon, high signal, flat peroneal groove, abnormal lateral ligaments, and fibular spurring.

The peroneus quartus muscle, which, when present, may contribute to attritional rupture of the peroneus brevis, can be noted on MRI as well. MRI also is excellent in imaging ruptures of the peroneus longus tendon. With peroneal tendon subluxation, MRI may allow identification of a small avulsion of the posterolateral fibula or redundancy of the SPR to aid in diagnosis. MRI is also invaluable in the diagnosis of ligament disorders, the grading of SPR injuries, the evaluation of the retrofibular groove, and the definition of tendon contours. (See the images below.)

Turbo spin-echo (TSE) T1-weighted MRI shows hypoinTurbo spin-echo (TSE) T1-weighted MRI shows hypointense peroneus quartus tendon (arrow) with muscle belly seen posterior to peroneus longus and peroneus brevis tendon.
Coronal short TI inversion recovery (STIR)-sequencCoronal short TI inversion recovery (STIR)-sequence MRI shows hyperintense calcaneofibular ligament at fibular attachment (left) and calcaneal attachment (right).

One must be familiar with the “magic angle phenomenon,” in which fibers of the tendon, when oriented 55º to the magnetic field axis, show an artifact appearing as an intratendinous signal that can be mistaken for tenosynovitis, degeneration, or tearing of the tendon.

Computed tomography

Computed tomography (CT) may show retrofibular groove anatomy, small avulsion fractures (“fleck” sign), and os peroneum pathology. (See the image below.) Axial CT images can reveal peroneal tendon dislocation. Three-dimensional (3D) color volume-rendered CT imaging of the ankle was studied by Ohashi et al in cases of peroneal tendon dislocation associated with acute calcaneal fractures but was found to be not as good as multiplanar imaging for the diagnosis of peroneal tendon dislocation in these patients. [25]

Plain lateral radiograph (left) shows os peroneum.Plain lateral radiograph (left) shows os peroneum. Axial CT (right) shows os peroneum adjacent to cuboid bone .

Ultrasonography

Ultrasonography (US) is rapidly gaining popularity for the evaluation of peroneal tendon disorders. It is easily available, inexpensive, noninvasive, and free of ionizing radiation, though it is operator-dependent and has a substantial learning curve.

US can reveal tendon thickening, partial or complete ruptures, and fluid around tendons. Moreover, it allows dynamic real-time evaluation of peroneal subluxation on provocative maneuvers and tendon splits that may be missed on MRI. US has been reported to be more sensitive and accurate than MRI for the diagnosis of tendon lesions around the ankle. [26]

Procedures

If peroneal tendon pathology is suspected, local anesthetic may be injected into the tendon sheath to aid in the diagnosis. Mizel et al injected bupivacaine mixed with contrast material into the peroneal tendon sheath to ensure accurate placement. [27Frequently, injections communicated with the ankle or subtalar joints, raising questions about the purity of the results.

Peroneal tendoscopy has been employed to diagnose the peroneal tendon pathologies. Tendoscopy allows exploration of the whole tendon surface from the myotendinous junction to the peroneal tubercle, using a minimally invasive approach that reduces the likelihood of postoperative scarring and nerve entrapment. Moreover, it allows dynamic evaluation of peroneal tendons under direct visualization by passive movements at the ankle.



Approach Considerations

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 therapeautic tool still lacks support from level I and II studies. The role of platelet-rich plasma in the treatment of peroneal tendon pathologies remains to be defined.

Medical Therapy

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. [29]

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

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 Therapy

Surgical treatment is best considered in the context of the specific pathology being addressed. [30With 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.)

Peroneus brevis degeneration forming ganglion-typePeroneus brevis degeneration forming ganglion-type mass.
Peroneus brevis above after resection of degeneratPeroneus brevis above after resection of degenerative mass and peroneus longus below.
Partial repair of peroneal tendon sheath. Partial repair of peroneal tendon sheath.
Repaired peroneal tendon sheath. Repaired peroneal tendon sheath.
Skin closed over peroneal tendon repair. Skin closed over peroneal tendon repair.

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

Cystic mass (ganglion) on right arising from peronCystic mass (ganglion) on right arising from peroneal tendon (×40).
Ganglion with myxoid degeneration and connective tGanglion with myxoid degeneration and connective tissue with myxoid material pools with cystic change (×400).

Tenosynovitis

Tenosynovitis may be treated surgically with simple division of the tendon sheath. Coughlin's description of the procedure is as follows. [3132]

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 advocate adding a lateral closing wedge calcaneal osteotomy (Dwyer) if the patient has a cavus or varus deformity of the hindfoot. [433]

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. [31]

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. [343536373839]

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. [40In 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 categories, as follows. [4142]

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.  

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. [43  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.)

Lateral view of ankle, with marking of distal fibuLateral view of ankle, with marking of distal fibula, base of fifth metatarsal, and intended incision.

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 intervention 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. [44 At present, only level IV and V studies on peroneal tendoscopy are available; these 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. [45]

Complications

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.


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