DEFINITION

Pathology of the peroneal tendons may be due to a singular traumatic episode or recurrent ankle sprains. In patients undergoing surgery for ankle instability, 25% have peroneal tendon tears; however, the true incidence is unknown.4

Isolated tears of the peroneus brevis and longus are rare.

When recognized early, direct repair is possible with good results.2,3

Delays in diagnosis are common, as up to 40% of peroneal tendon disorders are missed at first evaluation.5

 

 

ANATOMY

 

The peroneus brevis and longus are innervated by the superficial peroneal nerve and reside in the lateral compartment of the leg.

 

The peroneal longus attaches to the base of the first metatarsal and medial cuneiform and is responsible for plantar flexion of the first ray and eversion. Its muscular antagonist is the tibialis anterior.

 

The peroneal brevis attaches to the base of the fifth metatarsal and acts to evert and plantarflex the foot. Its muscular antagonist is the tibialis posterior. The brevis often has a low-lying muscle belly.

 

At the level of the lateral malleolus, the peroneus brevis is directly posterior to the bone; the longus is posterior to the brevis.

 

Both peroneal tendons are tethered at the level of the lateral malleolus in the fibular groove by the superior peroneal retinaculum, a 1- to 2-cm fibrous sling that extends from the tip of the lateral malleolus to the calcaneus. Disruption of this retinaculum can cause a subluxation of the tendons.

 

The inferior peroneal retinaculum is continuous with the inferior extensor retinaculum anteriorly and passes obliquely down to insert onto the lateral surface of the calcaneus. At this level, the peroneal tubercle of the calcaneus is a bony ridge that separates the brevis and longus. Injury to the inferior retinaculum does not allow for tendon subluxation.

PATHOGENESIS

 

The peroneal tendons may be injured in an inversion ankle sprain (FIG 1) or in chronically unstable ankles.

 

 

Contributing factors to tearing include tendon subluxation, superior retinacular stenosis,1 a low-lying peroneal brevis muscle belly,7 the presence of a peroneus quartus,17 and tenosynovitis.

 

The most common location for longitudinal peroneus brevis tendon tears is at the fibular groove,12 whereas the most common location for a peroneus longus tear is at the peroneal tubercle, at the entry of the cuboid tunnel.

 

At the fibula, both the peroneus longus and brevis have reduced vascularity.13

 

NATURAL HISTORY

 

 

Peroneal tendon pathology can be commonly overlooked in a patient with chronic lateral ankle pain. Anatomic variants may predispose to peroneal tendon tears. For example, a shallow retromalleolar groove predisposes the peroneals to subluxation or dislocation.15

 

Peroneal tendons that frequently subluxate or dislocate causes fraying at the tip of the fibula, as the tendons are constantly exposed to abnormal loads.

 

Additionally, the fibrocartilage of the distal fibula may hypertrophy and cause splitting of the brevis tendon.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

Patients may present after a severe ankle sprain or chronic lateral ankle instability.

 

Acute or chronic swelling and pain along the posterior border of the distal fibula is an important clinical indicator of peroneal pathology.

 

Palpation along the course of the peroneal tendons is important in eliciting pain. Pain at the tip of the fibula is

usually due to a tear of the peroneus brevis10 as compared to the peroneus longus tear, which presents as pain close to the base at the fifth metatarsal or cuboid tunnel.

 

Pain may be associated with active, resisted eversion and ankle dorsiflexion. The patient may also experience subluxation of the tendons with this maneuver.

 

On eversion strength testing, patients can have considerable weakness and pain.

 

Alignment of the affected lower extremity must be assessed. A fixed hindfoot varus deformity may need to be corrected at the time of surgery.

 

The single heel rise is helpful to evaluate the normal inversion (varus) alignment of the hindfoot.

 

 

 

FIG 1 • Radiograph of inversion stress test demonstrating left ankle instability.

 

 

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FIG 2 • A. Fleck sign: Note avulsed bone fragment from distal lateral fibula. B. Oblique radiograph of right foot demonstrating irregular os peroneum. In some peroneus longus tears, the os peroneum will be separated into two distinct fragments.

 

 

The peroneal tunnel compression test is used to evaluate peroneus longus tears. One applies manual pressure along the peroneal tendon sheath in the retromalleolar groove with the knee flexed to 90 degrees and the foot in a

 

resting plantar flexed position.14 A peroneal longus tendon tear may be present if the first ray does not plantarflex. Circumduction of the foot may reveal subluxating or dislocating peroneal tendons.

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Weight-bearing ankle and foot radiographs must be obtained.

 

Radiographs may show a “fleck sign” (FIG 2A) at the lateral most border of the fibular tip. This represents an avulsion of the superior peroneal retinaculum and is pathognomonic.6

 

The os peroneum (FIG 2B), if present, should be identified. Any fragmentation or displacement of this sesamoid may indicate peroneal longus disruption.

 

Ultrasonography can identify peroneal tendon tears with 90% to 100% accuracy, 100% sensitivity, and 85% to 100% specificity.8,11,16

 

 

 

FIG 3 • T2-weighted axial MRIs demonstrating a peroneus brevis tear. A. Posterior to distal fibula, peroneus brevis, the more anterior tendon, appears intact. B. More distally, the peroneus brevis tendon demonstrates signal change. C. At the distal fibula, there is a greater signal change within the peroneus brevis tendon. D. Immediately distal to the tip of the fibula, more extensive signal change in peroneus brevis tendon, suggesting degenerative tear.

 

 

Magnetic resonance imaging (MRI) is generally useful in confirming peroneal tendon pathology, demonstrating tears in the substance of the tendon and fluid in the sheaths. Associated pathology of the ankle can be identified as well (FIGS 3 and 4).

 

DIFFERENTIAL DIAGNOSIS

Stress fracture of fibula, cuboid, or fifth metatarsal Lateral ankle instability

Acute fracture of os peroneum or lateral process of the talus Ankle or syndesmosis sprain

Talar osteochondral lesions Sinus tarsi syndrome Calcaneocuboid syndrome Degenerative joint disease Accessory muscle/bone Hypertrophic peroneal tubercle Sural neuritis

 

 

NONOPERATIVE MANAGEMENT

 

Functional rehabilitation includes range of motion for the ankle and hindfoot, concentric and eccentric muscle strengthening, endurance training with particular attention to the peroneal musculature, and proprioceptive exercises.

 

Functional bracing or taping may be useful to help prevent recurrent injury during “at-risk” activities.

 

The senior author avoids performing corticosteroid injections to avoid any unnecessary risk of causing rupture or further damage to the tendons.

SURGICAL MANAGEMENT

Preoperative Planning

 

All imaging studies must be reviewed so that the location of the lesion is identified. MRI is often useful in identifying the exact level of peroneal tendon pathology.

 

Plain films must be reviewed for associated pathology, including degenerative changes, malalignment, and fractures. The ankle radiographs may reveal an avulsion of the superior peroneal retinaculum.

 

 

49

 

 

 

 

FIG 4 • T2-weighted axial MRIs demonstrating a peroneus longus tear. A. Posterior to distal fibula, peroneus longus, the more posterior tendon, appears intact. B. More distally, the peroneus longus tendon is thickened. C. More distally, adjacent to the talus, there is a signal change within the peroneus longus tendon. D. Even more distally, in the foot adjacent to the calcaneus, more extensive signal change in peroneus longus tendon, suggesting degenerative tear.

 

Positioning

 

The patient is placed in a modified lateral or full lateral decubitus position.

 

Saline bags or large blanket bumps are placed under the ipsilateral hip to achieve a lazy lateral position; a beanbag may be used to maintain a full lateral decubitus position.

 

A well-padded thigh tourniquet is placed.

 

The operative foot is elevated, with a bump made of blankets under the sterile field or with sterile towels within the

sterile field.

TECHNIQUES

• Preliminary Steps

Exposure

An 8- to 12-cm longitudinal incision is centered over the course of the peroneal tendons, beginning 1 cm posterior and proximal to the tip of the fibula.

Depending on the preoperative plan, the incision may need to be extended to the base of the fifth metatarsal or just distal to the distal tip of the fibula.

Care must be taken to identify and protect the saphenous vein and sural nerve in the distal aspect of the incision, which is subcutaneous and just posterior to the incision. A hemostat is often the best tool to achieve blunt dissection in this region.

The nerve, once identified, is tagged with a purple skin scribe or a vessel loop.

The peroneal sheath is inspected for redundant tissue that may be suggestive of inflammation (TECH FIG 1). The tendons are manipulated in order to elicit any subluxation.

 

 

At this point, the superior retinaculum is incised.

 

Usually, the peroneus longus tendon is encountered first.

Inspecting and Débriding the Peroneal Tendons

 

The tendon is inspected both proximally and distally (in light of the preoperative MRI) in order to document any tearing or degeneration. Oftentimes, the inferior peroneal retinaculum must be incised to fully appreciate the longus.

 

Once this tendon has been thoroughly inspected, a tenosynovectomy is performed sharply with a no. 15 blade scalpel.

 

Degenerated or nonviable tendon is excised. Any low-lying peroneus muscle belly that may create impingement posterior to the fibula should also be excised.

 

 

The peroneus brevis is then inspected and any residual pathology is documented. After comprehensive tenosynovectomy and tendon débridement, repair is initiated.

Treatment Decision

 

Once both tendons have had an extensive synovectomy and débridement, a treatment decision must be made. The senior author conceptualizes this similar to the algorithm proposed by Krause and Brodsky.9

 

For tendons that have damage to less than 50% of their crosssectional area, the tendon is considered salvageable.

 

In tendons which have greater than 50% of their cross-sectional areas débrided due to degeneration, the stump is tenodesed to the other peroneal tendon (assuming it is viable).

 

If both tendons have over 50% degeneration, another algorithm, based on Redfern and Myerson,10 is used.

 

 

If the proximal muscle bellies are not mobile, then a tendon transfer is performed. If there is some proximal muscle excursion:

 

 

If the tissue bed is scarred: silicone rod-staged reconstruction If the tissue bed is mobile: allograft or tendon transfer

 

 

 

TECH FIG 1 • Peroneal tendon sheath fullness suggests inflammation.

 

 

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• Repair of a Peroneus Brevis Tear in Isolation

   

  MRI scan is typically accurate in identifying peroneal tendon tears and may be useful in determining the location of the tear (see FIG 3).

   

   

  If the damage is less than 50% of the cross-sectional area of the tendon: The area of the longitudinal split is inspected (TECH FIG 2A,B).

   

  If present, a low-lying muscle belly that may impinge within the peroneal sheath should be excised (TECH

  FIG 2C).

   

  The diseased/degenerated portion of the peroneus brevis tendon is excised (TECH FIG 2D,E).

   

   

   

  TECH FIG 2 • A,B. Peroneus brevis tendon tear. A. Thickened tendon is consistent with MRI findings in FIG 3D. B. A longitudinal split tear creates a loss of contour of the tendon. C. Débridement of low-lying peroneus brevis muscle. The bulbous thickening of the peroneus brevis tendon is characteristic of chronic tendon tear/degeneration. D. Débridement of diseased portion of peroneus brevis tendon. E. Residual healthy fibers of débrided peroneus brevis tendon. F-H. Peroneus brevis tendon repair. F. Proximal anchoring suture. G. Repair via tubularization of the peroneus brevis tendon. H. Distal repair reinforced with a combination of interrupted and running sutures. (continued)

   

   

  Using an absorbable 3-0 suture, the tendon is repaired in a tubularized fashion.

   

  At one end of the longitudinal tear, a surgeon's knot is thrown (TECH FIG 2F,G).

   

  In a whipstitch/running fashion or in an interrupted simple suturing technique, each end of the split is

  captured to reestablish a smooth tendon (TECH FIG 2H).

   

   

  The superficial peroneal retinaculum is then repaired (TECH FIG 2I,J). If the damage is greater than 50% of the cross-sectional area of the tendon:

   

  The diseased tendon is excised with a scalpel.

   

  The viable proximal and distal tendon are tenodesed to the peroneal longus tendon with a 2-0 absorbable suture

   

  51

  where the stumps lie when the foot is in a neutral position. This should be done for at length of about 2 cm to improve strength of the repair.

   

   

   

  TECH FIG 2 • (continued) I,J. Repair of the superficial peroneal retinaculum following peroneus brevis repair. I. Retinaculum being sewn after peroneal tendons reduced to their anatomic position. J. Imbrication of the superior peroneal retinaculum with tendons reduced posterior to fibula.

   

   

  Usually, the proximal tenodesis is 3 to 4 cm proximal to the tip of the fibula and the distal tenodesis is 5 to 6 cm distal to the fibular tip.

   

  A (rare) rupture of the peroneal brevis from the base of the fifth metatarsal requires securing the tendon stump to its insertion.

   

   

  Prepare a bleeding bone bed at the anatomic footprint of the base of the fifth metatarsal. Use a 3.5-mm suture anchor to secure the stump to the bone.

• Repair of a Peroneus Longus Tear in Isolation

   

  MRI scan is typically accurate in identifying peroneal tendon tears and may be useful in determining the location of the tear (see FIG 4).

   

   

  If the damage is less than 50% of the cross-sectional area of the tendon: The area of the longitudinal split is inspected (TECH FIG 3A-C).

   

  The diseased/degenerated portion of the peroneus brevis tendon is excised (TECH FIG 3D,E).

   

  Using an absorbable 3-0 suture, the tendon is repaired in a tubularized fashion (TECH FIG 3F,G).

   

  An imbricating suture pattern is used to create the tubularization (TECH FIG 3H-J).

   

  In a whipstitch/running fashion, each end of the split is captured to reestablish a smooth tendon (TECH

  FIG 3K).

   

   

   

  TECH FIG 3 • A. Peroneus longus tendon degeneration identified, corresponding to MRI findings in FIG 4C. B. Tendon degeneration corresponding to MRI findings in FIG 4D. (continued)

   

   

  The superficial peroneal retinaculum is then repaired (TECH FIG 3L,M).

   

  If the damage is over half of the cross-sectional area of the tendon, the tendon is tenodesed to the peroneal brevis tendon with a 2-0 absorbable suture where the residual tendon lies when the foot is in a neutral position.

   

  If the os peroneum is fractured and needs to be excised, then the dissection must be extended distally to visualize the tendon, diving below the cuboid. The abductor muscle must be retracted inferiorly.

   

  If the tendon is disrupted transversely (after the os is removed), then the tendon ends are reapproximated and can be repaired end to end with a nonabsorbable suture.

   

  If the tendon cannot be repaired end to end, then the tendon may be tenodesed to the peroneus brevis tendon.

   

  If the tendon does not have excursion, then a tenodesis should not be performed because it may limit the function of the peroneus brevis tendon.

   

   

  52

   

   

   

  TECH FIG 3 • (continued) C. Distal tendon degeneration at the os peroneum. D,E. Débridement of diseased portion of peroneus longus tendon. D. Tenosynovectomy and partial tendon excision. E. Excision of central tendon degeneration in more distal portion of tendon. F. Healthy tendon fibers after central portion of diseased tendon excised. G. Planned tubularization of residual healthy tendon. H. Suture pattern to create tubularization.

  I. Tendon overlapped to create tubularized repair. J. Tendon repair secured. K. More proximal interrupted suture to reinforce repair. L,M. Repair of the superficial peroneal retinaculum following peroneus longus repair.

  L. Retinaculum being sewn after peroneal tendons reduced to their anatomic position. M. Imbrication of the superior peroneal retinaculum with tendons reduced posterior to fibula.

• Repair of a Peroneus Brevis Tear with Fibular Groove Deepening

 

 

The peroneus brevis tendon may have a tear due to chronic subluxation around the distal fibula. The tear should be inspected (TECH FIG 4A).

 

Any structures that may cause impingement within the peroneal tendon sheath such as a low-lying peroneus brevis muscle belly or inflamed tenosynovium should be excised (TECH FIG 4B).

 

The diseased portion of tendon is excised (TECH FIG 4C-E).

 

The tendon is assessed for a persistent tendency to subluxate (TECH FIG 4F).

 

If subluxation persists, then a fibular groove deepening is performed (TECH FIG 4G-I).

 

The peroneus brevis tendon is repaired via tubularization using absorbable suture (TECH FIG 4J).

 

The peroneal tendons are reduced in their anatomic position, now without tendency to subluxate following

fibular groove deepening (TECH FIG 4K).

 

The superior peroneal retinaculum is repaired (TECH FIG 4L,M).

 

 

53

 

 

 

 

TECH FIG 4 • A. Right peroneus brevis tear due to recurrent tendon subluxation at tip of fibula. B. Flexor tenosynovectomy. C. Identifying degenerative peroneus tendon tear. D. Débridement of degenerated portion of tendon anteriorly. E. Débridement of degenerated portion of tendon posteriorly. F. Despite débridement and tenosynovectomy, the peroneus brevis tendon continues to subluxate anterior to the fibula. G. Microsagittal saw creating “trapdoor” in posterior distal fibula. H. Trapdoor hinged open and distal fibula decancellated to create deeper fibular groove. I. With trapdoor reduced after decancellation, deeper fibular groove established. J. Peroneus brevis tendon repair via tubularization. K. Peroneal tendons now remain reduced even without superior peroneal retinacular repair. L. Superficial peroneal retinaculum being sewn after peroneal tendons reduced to their anatomic position. M. Imbrication of the superior peroneal retinaculum with tendons reduced posterior to fibula, with sutures passed through the bony ledge created by fibular groove deepening.

 

 

 

54

Indication

• Complete history and physical examination

• Address associated malalignment and pathology such as ankle instability.

Incision

• Avoid injury to the sural nerve.

Débridement

• Perform adequate débridement of the peroneal tendons.

Tubularization ▪ The goal is to create a smooth tendon surface. One should try to bury the first and

last knots of the suture.

PEARLS AND PITFALLS

 

 

POSTOPERATIVE CARE

 

Patients are initially placed in a bulky Jones dressing for the first 2 weeks.

 

Thereafter, they are allowed to bear weight as tolerated in a removable short-leg walking boot.

 

They are instructed to remove the boot four times a day and perform active and passive range-of-motion exercises of the ankle and hindfoot in all planes of motion.

 

Home strengthening exercises are begun at 8 weeks, and the patient is advanced to an ankle stirrup at 12 to 14 weeks based on his or her strength.

 

All patients are enrolled in formal physical therapy for functional rehabilitation of the ankle starting at 8 weeks.

OUTCOMES

Data on the 6.5-year follow-up of 18 patients has been published by Demetracopoulos et al.3

These patients had débridement and primary repairs (tubularization) of their peroneus longus and brevis tendons who had less than 50% débrided.

There were no reoperations or failures during this time interval.

There was a significant improvement in the postoperative visual analog scale (VAS) and Lower Extremity Functional Scale scores.

Seventeen of 18 patients returned to full sporting activities without limitation.

 

 

COMPLICATIONS

Wound complications

Sural neuralgia or sural nerve injury Chronic pain

Rerupture

 

 

REFERENCES

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2. Cox D, Paterson FW. Acute calcific tendinitis of peroneus longus. J Bone Joint Surg Br 1991;73(2):342.

    

    

3. Demetracopoulos CA, Vineyard JC, Kiesau CD, et al. Long-term results of debridement and primary repair of peroneal tendon tears. Foot Ankle Int 2014;35(3):252-257.

    

    

4. DiGiovanni BF, Fraga CJ, Cohen BE, et al. Associated injuries found in chronic lateral ankle instability. Foot Ankle Int 2000;21(10): 809-815.

    

    

5. Dombek MF, Lamm BM, Saltrick K, et al. Peroneal tendon tears: a retrospective review. J Foot Ankle Surg 2003;42(5): 250-258.

    

    

6. Eckert WR, Davis EA Jr. Acute rupture of the peroneal retinaculum. J Bone Joint Surg Am 1976;58(5):670-672.

    

    

7. Geller J, Lin S, Cordas D, et al. Relationship of a low-lying muscle belly to tears of the peroneus brevis tendon. Am J Orthop 2003;32(11): 541-544.

    

    

8. Grant TH, Kelikian AS, Jereb SE, et al. Ultrasound diagnosis of peroneal tendon tears. A surgical correlation. J Bone Joint Surg Am 2005;87(8):1788-1794.

    

    

9. Krause JO, Brodsky JW. Peroneus brevis tendon tears: pathophysiology, surgical reconstruction, and clinical results. Foot Ankle Int 1998;19(5):271-279.

    

    

10. Redfern D, Myerson M. The management of concomitant tears of the peroneus longus and brevis tendons. Foot Ankle Int 2004;25(10): 695-707.

     

     

11. Rockett MS, Waitches G, Sudakoff G, et al. Use of ultrasonography versus magnetic resonance imaging for tendon abnormalities around the ankle. Foot Ankle Int 1998;19(9):604-612.

     

     

12. Sammarco GJ, DiRaimondo CV. Chronic peroneus brevis tendon lesions. Foot Ankle 1989;9(4):163-170.

     

     

13. Sobel M, Geppert MJ, Hannafin JA, et al. Microvascular anatomy of the peroneal tendons. Foot Ankle 1992;13(8):469-472.

     

     

14. Sobel M, Geppert MJ, Olson EJ, et al. The dynamics of peroneus brevis tendon splits: a proposed mechanism, technique of diagnosis, and classification of injury. Foot Ankle 1992;13(7): 413-422.

     

     

15. Title CI, Jung HG, Parks BG, et al. The peroneal groove deepening procedure: a biomechanical study of pressure reduction. Foot Ankle Int 2005;26(6):442-448.

     

     

16. Waitches GM, Rockett M, Brage M, et al. Ultrasonographic-surgical correlation of ankle tendon tears. J Ultrasound Med 1998;17(4): 249-256.

     

     

17. Zammit J, Singh D. The peroneus quartus muscle: anatomy and clinical relevance. J Bone Joint Surg Br

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