DEFINITION

Lateral ankle injuries are among the most common musculoskeletal injuries in the athletic population. Rates as high as 7 per 1000 person-years have been reported in the general population.

From 10% to 20% of sprains progress to some kind of chronic symptoms.

Determining whether the patient's instability is functional (ie, subjective giving way) or mechanical (ie, motion beyond the normal physiologic limits) is important for formulating treatment recommendations.

 

 

ANATOMY

 

The lateral ankle ligament complex consists of the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL), and posterior talofibular ligament (PTFL).

 

The ATfloriginates from the anterior aspect of the distal fibula and inserts on the lateral aspect of the talar neck. It is often ill defined and, in the chronically sprained ankle, may be manifest as a capsular expansion.

 

The ATfllimits anterior translation of the talus with the ankle in neutral and becomes the primary restraint to inversion when the ankle is plantarflexed.

 

The Cfloriginates from the distal tip of the fibula and inserts on the lateral wall of the calcaneus (FIG 1A,B).

 

The Cflmeasures 4 to 6 mm in diameter and 13 mm in length and is directed posteriorly 10 to 45 degrees from the tip of the fibula.

 

The Cflfunctions to resist inversion with the ankle in neutral.

 

The anterior margin of the talus is wider than the posterior margin, which makes the ankle more susceptible to inversion injuries while in plantarflexion.

 

The peroneal tendons provide dynamic stability to the ankle joint.

 

 

 

 

FIG 1 • The CFL is directly deep to the peroneal tendons as demonstrated by this surgery to repair peroneal

tendon dislocation. A. Peroneal tendons in their anatomic location. B. CFL identified when peroneal tendons are retracted.

 

PATHOGENESIS

 

 

An inversion force with the ankle in plantarflexion is the most common mechanism of injury. The ATfltypically is the first ligament injured, followed by the CFL.

 

Ligament ruptures are most commonly midsubstance tears or avulsions off of the talus.

 

NATURAL HISTORY

 

Despite a relatively high incidence of lateral ankle injuries, most patients do well with nonoperative management.

 

Patients are at increased risk for recurrent lateral ankle sprains after sustaining the initial injury and failing to rehabilitate completely.

 

Chronic lateral instability may lead to progressive loss of function and osteoarthritic changes of the ankle.

 

PATIENT HISTORY AND PHYSICAL FINDINGS

 

Patients with chronic ankle instability frequently present with pain as well as complaints of multiple sprains caused by minor provocation.

 

Duration of symptoms, the type of incidents that cause sprains, the need for functional bracing, and previous treatments are important for determining treatment recommendations.

 

If pain is present between episodes of instability, other lesions about the ankle should also be considered.

 

An anterior drawer test with a bony end point that is distinctly different from that of the contralateral ankle is considered markedly positive.

 

Physical examination techniques include the following:

 

Palpation. Palpate the ATFL, CFL, syndesmosis, medial and lateral malleoli, peroneal tendons, base of the fifth metatarsal, and anterior process of the calcaneus.

 

 

00

 

 

 

FIG 2 • Anterior drawer test. A. Ankle reduced. B. Anterior subluxation.

 

 

Anterior drawer test (FIG 2A,B). The ankle is held in plantarflexion, and the talus is translated forward relative to the tibia. With intact medial structures, the displacement is rotatory. Translation of 5 mm more than the contralateral ankle or absolute translation of 9 to 10 mm is a positive test and suggests an incompetent ATFL. Grading ATFL injuries: I, stretching; II, partial tearing; III, complete rupture; most useful in the acute setting to determine which structures are injured.

 

Talar tilt. The heel is inverted with the ankle in neutral. Range of motion is compared to the contralateral ankle. Increased inversion is suggestive of a CFL injury.

 

Alignment. Assess the standing alignment of the hindfoot. Varus hindfoot alignment predisposes the ankle to inversion injury.

 

IMAGING AND OTHER DIAGNOSTIC STUDIES

 

Standard radiographs should include standing anteroposterior (AP), lateral, and mortise views to evaluate for anterior tibial marginal osteophytes, talar exostoses, osteochondral lesions of the talus, or intra-articular loose bodies.

 

Talar tilt can be assessed with inversion stress mortise views of the ankle (FIG 3A).

 

Comparison views of the contralateral ankle should also be obtained.

 

A talar tilt angle greater than 10 degrees, or 5 degrees greater than the contralateral ankle, is considered pathologic laxity.

 

 

 

 

FIG 3 • Radiographic stress tests. A. Positive talar tilt test. B. Positive anterior drawer test.

 

 

Anterior translation stress radiographs can be obtained by performing the anterior drawer test and shooting a lateral radiograph (FIG 3B).

 

Comparison stress views of the contralateral ankle should also be obtained.

 

Anterior translation 5 mm greater than the contralateral ankle, or an absolute value of greater than 9 mm, is suggestive of instability.

 

Stress radiographs may be helpful, but physical examination remains the gold standard for evaluation of instability.

 

Magnetic resonance imaging (MRI) can be useful to evaluate the ligamentous injury as well as peroneal tendon pathology and suspected osteochondral injuries.

 

DIFFERENTIAL DIAGNOSIS

Lateral process talar fracture Anterior process calcaneus fracture Base of the fifth metatarsal fracture Tarsal coalition

Osteochondral lesion of the talus or tibia Subtalar instability

Syndesmosis injury

Neurapraxia of the superficial peroneal or sural nerve Peroneal tendon tear

 

Peroneal instability

Sinus tarsi syndrome

Anterolateral ankle soft tissue impingement

 

 

NONOPERATIVE MANAGEMENT

 

Physical therapy should be the initial treatment for patients with chronic instability.

 

 

Proprioceptive training and peroneal tendon strengthening are the most important features. The duration of therapy varies based on strength deficiencies and the intensity of the program.

 

 

External stabilization of the ankle with taping or bracing can be effective. Taping provides tibiotalar stability, but quickly deteriorates with activity.

 

Reusable braces provide similar stability, but do not lose effectiveness with activity.

 

Orthotic devices and shoe wear modification can also be used when foot or ankle malalignment contributes to the instability.

 

 

01

 

 

 

 

FIG 4 • With the patient in the lateral decubitus position, the nonoperated extremity should be well padded. A. Nonoperated leg in a gel pad. B. With the nonoperated leg protected, a platform may be used to facilitate positioning of the operated leg. C. Alternatively, positioning in the lateral decubitus position, using a stack of folded sheets to serve as a rest for the operated leg.

 

SURGICAL MANAGEMENT

 

If the patient fails 3 to 6 months of conservative treatment and has persistent signs and symptoms of functional and mechanical instability, he or she becomes a candidate for the modified Brostrom procedure or the modified Brostrom-Evans procedure, which is a combination of the modified Brostrom procedure and the Evans procedure, in which the anterior 50% of the peroneus brevis (PR) is tenodesed to the fibula.

 

Indications for the Brostrom-Evans procedure

 

Athlete or patient in whom greater restraint against inversion is desired, such as football lineman who does not need as much hindfoot flexibility as a running back

 

Anatomic repair planned but greater than anticipated instability, particularly with inversion stress, and an intraoperative determination that more restraint to inversion is needed than can be afforded by the modified Brostrom procedure alone

 

Lateral ankle instability in a patient with preexisting longitudinal split tear of the PR

Preoperative Planning

 

The history must be considered. A relative contraindication for this anatomic repair is generalized ligamentous laxity as might be encountered in Ehlers-Danlos syndrome.

 

Carefully review the physical examination. If a varus heel exists, a Dwyer-type calcaneal osteotomy should be considered.

 

 

 

 

FIG 5 • A. A traditional J approach on the anterior distal fibula. B. An extensile curvilinear exposure to the lateral ankle. This approach facilitates access to the peroneal tendons; should there be associated peroneal tendon pathology.

 

 

If an osteochondral lesion is present, the ligamentous reconstruction should be done in conjunction with arthroscopic or open treatment of the osteochondral defect.

 

Positioning

 

The patient is placed in the lateral decubitus position with appropriate padding at bony prominences to avoid damage to subcutaneous structures (FIG 4A,B).

 

An operative platform is created using bolsters or blankets.

 

A “bump” made of four or five towels is used either proximal to the ankle to create a varus or inverted position for better exposure or distal to the ankle to create a valgus or everted position to approximate the edges of the repair (FIG 4C).

 

Approach

 

 

Two commonly used approaches J incision (FIG 5A)

 

The incision is made from the distal tip of the fibula along its anterior margin proximally to the level of the ankle mortise.

 

 

Does not afford optimal access to the peroneal tendons Curvilinear extensile exposure (FIG 5B)

 

Curvilinear incision over posterior tip of fibular, extending to sinus tarsi area

 

Affords comprehensive exposure to anterior ankle, ATFL, CFL, and peroneal tendons

 

 

02

 

TECHNIQUES

• Modified Brostrom Anatomic Lateral Ankle Ligament Repair with Suture Anchors

Perioperative antibiotics are given.

The patient is positioned as described, a thigh tourniquet is placed, and a standard orthopaedic prep and drape is carried out. The tourniquet is inflated.

The incision is made as described under Approach in the Surgical Management section (TECH FIG 1A).

With the bump placed proximal to the ankle, a dissection is carried out to isolate the inferior extensor retinaculum.

The joint capsule is then incised in line with the skin incision and just distal to the leading edge of the fibula. The ATflmay or may not be visible as a capsular expansion.

The Cflis inspected. This inspection, along with the preoperative evaluation, is used to decide whether or not a repair of this ligament is needed.

The joint is inspected for chondral injury.

A subperiosteal dissection is carried out at the anterior and lateral aspect of the fibula, raising a flap 3 to 6 mm wide.

Using curettes and rongeurs, a trough is made in the anterior and lateral aspect of the fibula at its leading edge, about 3 mm deep and 3 mm wide.

 

 

 

 

TECH FIG 1 • A. Traditional approach to perform the modified Brostrom repair. B. Suture anchors placed in the distal fibula.

 

 

If no Cflrepair is needed, a single corkscrew anchor double-armed with no. 2 FiberWire (Arthrex, Inc., Naples, FL) suture is inserted centrally in the trough. If a Cflrepair is performed, a second anchor with no. 2 FiberWire is used (TECH FIG 1B).

 

The joint is thoroughly irrigated, and the actual repair begins. Move the bump so it sits under the lateral border of the foot, placing the subtalar and ankle joints into an everted position before repairing the Cflif necessary.

 

The capsular ligament and ATflrepair is now performed by bringing the sutures from deep to superficial in a horizontal mattress pattern. The “ligament” is shortened by creating the trough at the fibula. If further shortening is needed, the capsule may be trimmed from the distal cut edge.

 

A second reinforcing layer of repair is created by suturing the inferior extensor retinaculum to the periosteal flap with absorbable 2-0 figure-8 sutures.

 

The skin is closed in layers with 3-0 absorbable suture in the subcutaneous layers and staples or subcuticular suture used in the skin.

 

Dressings are applied, and a short-leg non-weight-bearing splint is applied.

Case Example (Courtesy of Mark E. Easley)

 

Confirm ankle instability with examination under anesthesia.

 

A curvilinear incision is made over posterior tip of the fibula and extending to the sinus tarsi (TECH FIG 2).

 

Protect sural nerve posteriorly and superficial peroneal nerve anteriorly.

 

Prepare the inferior extensor retinaculum.

 

 

Identify and mobilize the inferior extensor retinaculum (TECH FIG 3A,B). Relatively thin superficial structure

 

 

Identify, inspect, and protect the peroneal tendons (TECH FIG 3C,D). Anterior arthrotomy

 

 

Detach the capsule, including the ATfland Cfl(TECH FIG 4A,B). Protect the peroneal tendons (TECH FIG 4C).

 

Excise the anterior inferior tibiofibular ligament (Bassett ligament) (TECH FIG 4D).

 

Usually present in patients after ankle sprain

 

 

Potential for anterolateral soft tissue ankle impingement Inspect the lateral talar dome for cartilage defect.

 

 

 

TECH FIG 2 • Curvilinear extensile exposure to the lateral ankle ligaments.

 

 

03

 

 

 

TECH FIG 3 • A,B. Mobilize the inferior extensor retinaculum to be used to augment the repair (Gould modification of the Brostrom procedure). A. Identify the inferior extensor retinaculum. B. Demonstrate that the retinaculum can be advanced. C,D. Identify, inspect, and protect the peroneal tendons. C. Identify the tendons. D. Inspect the tendons.

 

 

 

TECH FIG 4 • Anterior arthrotomy. A-C. The anterolateral capsule is elevated from the distal fibula. D. With the anterolateral tibiotalar joint exposed, the talar articular cartilage may be inspected and the hypertrophied anterior inferior tibiofibular ligament (Bassett ligament) may be excised. (Following multiple ankle sprains, anterolateral soft tissue ankle impingement frequently develops.)

 

 

04

 

 

 

TECH FIG 5 • Identify the ATfland Cflwithin the lateral capsule; these structures represent condensations within the lateral capsule. A,B. ATfland its anatomic location on the fibula identified. C,D. Cflidentified and its competency tested with ankle/hindfoot inversion.

 

 

Identify the ATfland Cfl(TECH FIG 5A-D); these are condensations within the capsular sleeve.

 

 

Develop a distal fibular periosteal flap (TECH FIG 6A,B) to use as an additional reinforcement of the repair. Prepare anterior distal fibula for reattachment of capsule and ligaments.

 

Create a trough using a rongeur (TECH FIG 6C).

 

Predrill anatomic footprints for ATfland Cflsuture anchor placement (TECH FIG 6D,E).

 

Place suture anchors (TECH FIG 7A,B).

 

 

 

Orient them so that they do not Interfere with one another Violate the joint

 

Violate the posterior cortex of the fibula and irritate the PR

 

 

 

TECH FIG 6 • Distal fibular periosteal flap. This flap may be developed to create another layer for repair.

A,B. Mobilizing distal fibular flap. (continued)

 

 

Test the stability of the suture anchors (TECH FIG 7C).

 

Lift the limb by the anchors; if the anchors are going to fail, we want them to do so now so the problem can be rectified.

 

Pass the respective sutures through the CFL, the adjacent capsule, and the ATfl(TECH FIG 7D-F).

 

Test the sutures to ensure that they indeed advance the appropriate portion of the capsule to the desired location on the distal fibula (TECH FIG 7G).

 

Position the ankle properly for securing the sutures (TECH FIG 8A).

 

Reduce the talus within the ankle mortise

 

 

Avoid anterior translation of the talus within the mortise Dorsiflex the ankle to neutral

 

Maintain slight hindfoot valgus

 

 

05

 

 

 

TECH FIG 6 • (continued) C. Using a rongeur to prepare the distal fibula for reattachment of the capsule. D,E. Predrill holes for suture anchors. D. First, drill hole in anatomic footprint of ATFL. E. Second, drill hole in anatomic footprint of CFL.

 

 

 

TECH FIG 7 • Suture anchors. A. First anchor in anatomic footprint of ATFL. B. Second anchor in anatomic footprint of CFL. C. Stability of suture anchors tested by lifting limb from the operating room table by the anchor sutures. D-G. Anchor sutures passed through respective capsular condensations. D. Suture through CFL. E. Suture through posterior aspect of capsule adjacent to CFL. (continued)

 

 

06

 

 

 

TECH FIG 7 • (continued) F,G. Suture through ATFL.

 

 

Tie the sutures (TECH FIG 8B-D).

 

 

Check the stability of the repair after the anchor sutures have been tied (TECH FIG 8E). Pass the anchor sutures through the distal fibular periosteal flap (TECH FIG 9A-C).

 

This reinforces the repair.

 

Place additional sutures from the periosteum to the capsule that has been advanced to the distal fibula (TECH FIG 9D,E).

 

Augment the repair further with the inferior extensor retinaculum.

 

 

 

TECH FIG 8 • A. Reduce the talus within the ankle mortise before reattaching the ligaments and capsule. The ankle is held in dorsiflexion, with a posterior force maintaining the talus within the ankle mortise.

Although covered, a bump has been placed under the distal tibia to allow the heel to translate posteriorly without interfering with the operating table. The heel is maintained in slight valgus. B-D. Secure the sutures while ankle is maintained in optimal position. B. Protect the peroneal tendons. C. Secure the Cfland more posterior capsule. (continued)

 

 

Protect the peroneal tendons because they are in close proximity to the inferior extensor retinaculum (TECH FIG 10A).

 

Advancing the inferior retinaculum to the distal fibula over the capsular advancement is the (Nathaniel) Gould modification of the Brostrom lateral ankle ligament reconstruction (TECH FIG 10B-D).

 

If possible, advance the inferior retinaculum so that the tissue covers the sometimes prominent permanent anchor suture knots. Final check of the anterior drawer and talar tilt tests to ensure that ankle stability has been reestablished (TECH FIG 11A).

 

Closure (TECH FIG 11B)

 

 

07

 

 

 

TECH FIG 8 • (continued) D. Secure the ATFL. E. Recheck the anterior drawer test to determine if the primary sutures are securely maintaining ankle stability.

 

 

 

TECH FIG 9 • Anchor sutures passed through the periosteal flap to reinforce the repair. A. Sutures through the periosteal flap. B. Check the stability. C. Secure the sutures. D,E. Reinforce the repair with additional sutures.

D. Pass sutures from the capsule through the periosteal flap. E. Secure these sutures.

 

 

08

 

 

 

TECH FIG 10 • Gould modification of the Brostrom procedure. A. Protect peroneal tendons. B. More posterior advancement of the inferior extensor retinaculum. C. Anterior advancement. D. Attempt to cover the permanent anchor sutures with the retinaculum.

 

 

 

TECH FIG 11 • A. Final check of anterior drawer and talar tilt tests to be sure repair is satisfactory. B. Closure.

• Modified Brostrom-Evans Procedure

 

Same positioning and approach as for a modified Brostrom procedure

 

The ATfland Cflare released with the capsular sleeve from the fibula, the same way as for the modified Brostrom procedure (TECH FIG 12A).

 

Preparing the PR tendon

 

The PR is isolated distal and proximal to the superior peroneal retinaculum (SPR) that is left intact.

 

The PR is split longitudinally and the anterior 50% is released proximally (TECH FIG 12B).

 

While keeping the SPR intact, the PR is split using a suture that is passed beneath the SPR that is used to separate the PR into anterior and posterior limbs, acting as a “saw” to divide the tendon along its longitudinal fibers.

 

After being released proximally, the anterior limb of the PR is passed beneath the SPR distally.

 

Passing the anterior limb of the PR through the fibula

 

Drill an oblique tunnel in the distal fibula (TECH FIG 13A).

 

 

Pass the anterior 50% of the PR through the tunnel from distal to proximal (TECH FIG 13B). Complete the modified Brostrom procedure (TECH FIG 13C,D).

 

The ankle is held in neutral position.

 

The talus is maintained in the ankle mortise.

 

Slight valgus is maintained in the hindfoot.

 

 

09

 

 

 

TECH FIG 12 • A. Prepare the lateral ankle ligament complex as is done for the isolated modified Brostrom procedure. B. Isolate the anterior 50% of the PR tendon.

 

 

Augment the modified Brostrom with the Evans modification.

 

The anterior slip of the PR is secured to the fibular periosteum, both at the anterior and posterior aspects of the tunnel.

 

Avoid excessive valgus or excessive tensioning, as overtightening could occur; the goal is to have a restraint to inversion, not a complete lack of inversion.

 

 

 

TECH FIG 13 • A. Transect the anterior 50% of the tendon proximally and pass this half of the PR tendon beneath the intact superficial peroneal retinaculum. Drill a fibular tunnel from distal to proximal.

B. Pass the anterior slip of the PR through the tunnel from distal to proximal. C,D. Complete the modified Brostrom procedure. (continued)

 

 

Typically, the anterior slip of the PR can be sewn over the fibula after being passed through the tunnel to further augment the repair (TECH FIG 13E,F).

 

Check ankle stability with anterior drawer test and particularly inversion stress test (TECH FIG 13G,H).

 

 

10

 

TECH FIG 13 • (continued) E,F. After passing through the fibular tunnel, the anterior slip of the PR may be folded distally over the fibula to augment the repair. Check the ankle stability: (G) anterior drawer and (H) inversion stress tests.

 

 

 

PEARLS AND PITFALLS

Incision

• When making the traditional J incision, be sure it is positioned over the distal fibula

and not the lateral process of the talus. Palpate the landmarks carefully.

Use a ▪ Position is everything. A bolster under the ipsilateral hip ensures that the leg is

bump/bolster maintained in the optimal position, thereby maintaining adequate exposure to the lateral ankle. A bolster under the operated ankle is also useful and improves access to the lateral ankle.

Ankle

position when securing the sutures

• Reduce the talus within the ankle mortise. Dorsiflex the ankle, push the talus

posteriorly within the mortise, and maintain slight hindfoot valgus. It is useful to use a bump under the distal tibia so that the foot can be pushed posteriorly.

Protect the

superficial peroneal nerve

• The superficial peroneus nerve crosses the anterior aspect of the surgical approach

for the classic J incision and potentially for the extensile exposure as well. Be careful not to injure the nerve.

 

POSTOPERATIVE CARE

The patient is to remain non-weight bearing until seen in the clinic for the first cast change in 10 to 14 days.

At this first postoperative visit, the splint is removed and wound evaluated. If no problems are seen, the skin closure is removed and the patient is placed in a short-leg weightbearing cast for the subsequent 4 to 5 weeks. Consider early mobilization with an ankle brace. Recent work has demonstrated that this leads to an earlier return to sport and work with fewer patients experiencing less satisfactory function.

At the next visit, the cast is removed and a physical therapy program is initiated for range-of-motion, proprioceptive training, and progressive resistive exercises.

Gradual return to sport is possible at 12 to 16 weeks following surgery.

 

 

COMPLICATIONS

Minimal; avoid injury to the superficial peroneal and sural nerves Infection

Wound dehiscence Failure of repair

Peroneal weakness (postoperative physical therapy program is important)

If the talus was not reduced within the ankle mortise when the sutures were secured, then the repair may prove inadequate.

With an anatomic repair, overtightening is unlikely.

 

 

11

SUGGESTED READINGS

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2. Broström L. Sprained ankles. VI. Surgical treatment of chronic ligament ruptures. Acta Chir Scand 1966;132:551-565.

    

3. Burks RT, Morgan J. Anatomy of the lateral ankle ligaments. Am J Sports Med 1994;22:72-77.

    

4. Colville MR. Surgical treatment of the unstable ankle. J Am Acad Orthop Surg 1998;6:368-377.

    

5. Colville MR, Marder RA, Boyle JJ, et al. Strain measurement in lateral ankle ligaments. Am J Sports Med 1990;18:196-200.

    

6. Colville MR, Marder RA, Zarins B. Reconstruction of the lateral ankle ligaments. A biomechanical analysis. Am J Sports Med 1992;20:594-600.

    

7. de Vries JS, Krips R, Sierevelt IN, et al. Interventions for treating chronic ankle instability. Cochrane Database Syst Rev 2006;(4):CD004124.

    

8. Hølmer P, Søndergaard L, Konradsen L, et al. Epidemiology of sprains in the lateral ankle and foot. Foot Ankle

    

   Int 1994;15:72-74.

    

    

9. Johnson EE, Markolf KL. The contribution of the anterior talofibular ligament to ankle laxity. J Bone Joint Surg Am 1983;65(1):81-88.

    

    

10. Peters JW, Trevino SG, Renstrom PA. Chronic lateral ankle instability. Foot Ankle 1991;12:182-191.