Current Concepts In Minimally Invasive Lateral Ankle Stabilization

We can broadly categorize lateral ankle stabilization as either surgical repair or reconstruction of unstable lateral collateral ankle ligaments secondary to partial or complete rupture or repeated sprains.

Surgeons may restore ankle stability via anatomic repair of the remaining ligaments with or without augmentation or reconstruction of lateral ligaments by autogenous, allogeneic or synthetic materials.

Let us take a closer look at a percutaneous approach for reconstruction of the anterior talofibular and calcaneofibular ligaments with a graft supplemented by interference screw fixation.

Step-By-Step Pearls On Performing The Surgical Procedure

Perform the procedure with the patient in the lateral recumbent position. Anesthesia is per the surgeon’s choice. Tourniquet hemostasis is preferable.

Make four percutaneous incisions. The first incision is along the anterior border of the lateral malleolus corresponding to the fibular attachment of the anterior talofibular ligament. The second incision is along the posterior-inferior border of the lateral malleolus corresponding to the fibular attachment of the calcaneofibular ligament. The third incision is on the lateral aspect of the calcaneus, inferior to the peroneal tendons and corresponding to the calcaneal attachment of the calcaneofibular ligament. Create a tunnel between the third and second incision beneath the peroneal tendons. Make the fourth incision on the lateral aspect of the talar neck, corresponding to the talar attachment of the anterior talofibular ligament.

Create drill holes for passage of the synthetic ligament. Use a 5.0 mm cannulated drill to ensure accurate placement in the lateral wall of the calcaneus and the lateral talar neck. Use a 4.0 mm cannulated drill to create an anterior-posterior hole in the fibular malleolus.

Drill the first wire (4.0 mm cannulated drill) posterior to anterior through the distal fibular malleolus. Drill the wire through the center of the lateral malleolus in oblique fashion, keeping the drilling lower posterior than anterior. Drill a second wire (5.0 mm cannulated drill) at the calcaneal attachment of the calcaneofibular ligament, perpendicular to the lateral wall of the calcaneus. The depth of the hole should be 15 to 20 mm.

Drill a third wire at the talar neck attachment of the anterior talofibular ligament laterally. We prefer to drill this wire through the entire talus, exiting the medial aspect of the foot. In larger individuals, it may be easier to drill the talar hole from medial to lateral. The medial surface of the talar neck is palpable and the starting point is readily accessible. From the medial side, aim the wire for the 5.0 mm cannulated drill just anterior to the lateral malleolus, which corresponds to the attachment of the anterior talofibular ligament.

Use an Artelon strip (Artelon) for the ligament reconstruction. Artelon comes in sizes of 0.3 or 0.5 x 16 cm. Place a whip stitch at both ends of the Artelon strip and then place the ligament through the drill hole in the fibula. Route the posterior portion of the Artelon strip below the peroneal tendons and into the calcaneal hole. Secure the strip with a 4.75 x 15 mm interference screw (Arthrex). Route the anterior portion of the Artelon strip through the talar hole. Feed a wire loop from lateral to medial through the talus and exiting the medial side of the foot. Pull the whip stitch out of the medial side of the foot and apply tension, pulling the strip into the talar hole.

Place the foot in the desired corrected position (neutral subtalar joint) and place appropriate tension on the Artelon ligament, taking care to take all the slack out of the replacement ligament. Then secure the Artelon ligament in the talar hole with a 4.75 x 15 mm interference screw. One may add stability by placing a third interference screw (measuring 3 x 8 mm) in the fibula. One may imbricate the surrounding soft tissue around the Artelon ligament. Close the percutaneous incisions in appropriate fashion.

Pertinent Postoperative Considerations

Apply a compressive dressing and emphasize to the patient that he or she stays non-weightbearing for three to four days. On the first postoperative visit, apply a lighter dressing and allow the patient protected weightbearing to tolerance in a controlled ankle motion (CAM) boot. Allow active range of motion (ROM) exercise after two weeks and active and passive ROM rehabilitation at the end of four weeks.
Unprotected weightbearing can usually happen by the end of the fifth or sixth week. Activity levels are variable and dependent on patient tolerance.

What You Should Know About The Emerging Ligament Reconstruction Procedure

There are many advantages with this technique. Anatomic reconstruction of the lateral collateral ligaments occurs without sacrificing anatomic structures. The peroneal tendons remain fully functional.  
Artelon is composed of inert polyurethane urea that is strong, creep-resistant and hyperelastic. Creep resistance protects the repair during acute healing. Hyperelasticity permits loading and stimulation during late remodeling.^1,2 Artelon is fabricated from extruded and wet-spun fibers of polyurethane urea that have been woven into textile patches and strips to optimize the mechanical properties.³

Artelon exhibits tensile strength comparable to the anterior talofibular ligament. The tensile strength for rupture of the anterior talofibular ligament ranges from 58 to 556 N with an average of 206 N.⁴ During the stance phase of gait, an average force of 130 N acts on the anterior talofibular ligament and an average force of 135 N acts on the calcaneofibular ligament.⁵ The rupture tensile strength for Artelon is 500 N and it maintains 90 percent of this strength at one year, 80 percent of this strength at two years and 50 percent of this strength at four years.³ Artelon allows for creeping substitution of ligament regenerate, integrates into the repair site without foreign body reaction and the body eliminates it via benign hydrolytic degradation.^6,7 These characteristics contribute to the effectiveness of Artelon in surgical repair.

Soft tissue complications are minimal due to the percutaneous approach. There have been no infections in our series of 33 cases. This approach accelerates weightbearing, active and passive rehabilitation, and return to activity. Pain is minimal. Operating room time is reduced to approximately 30 minutes as opposed to the usual 60 to 90 minutes, and surgeons perform the procedure on an outpatient basis.

This percutaneous approach has proven to be a simple, effective, reproducible and inexpensive method to stabilize the lateral collateral ligaments. Surgeons should evaluate this technique and determine if it complements their approach to this common pathology.

Dr. LaPorta is a Diplomate of the American Board of Foot and Ankle Surgery, and a Diplomate of the American Board of Podiatric Medicine. He is in private practice in Dunmore, PA and Vestal, NY. Dr. LaPorta is a Fellow of the American College of Foot and Ankle Surgeons.

Dr. Woodley is a third-year reconstructive rearfoot/ankle surgery resident at Geisinger Community Medical Center in Scranton, PA.

References

1. Giza E, Frizzell L, Farac R, Williams J, Kim S. Augmented tendon Achilles repair using a tissue reinforcement scaffold: a biomechanical study. Foot Ankle Int. 2011;32(5):S545-9.
2. Gisselfält K, Edberg B, Flodin P. Synthesis and properties of degradable poly(urethane urea)s to be used for ligament reconstructions. Biomacromolecules. 2002;3(5):951-8.
3. Artelon. Available at https://artelon.com/atfl-reconstruction/ .
4. St Pierre RK, Rosen J, Whitesides TE, et al. The tensile strength of the anterior talofibular ligament. Foot Ankle. 1983;4(2):83-5.
5. Ozeki S, Kitaoka H, Uchiyama E, et al. Ankle ligament tensile forces at the end points of passive circumferential rotating motion of the ankle and subtalar joint complex. Foot Ankle Int. 2006;27(11):965-9.
6. Liljensten E, Gisselfält K, Edberg B, et al. Studies of polyurethane urea bands for ACL reconstruction. J Mater Sci Mater Med. 2002;13(4):351-9.
7. Peterson L, Eklund U, Engström B, et al. Long-term results of a randomized study on anterior cruciate ligament reconstruction with or without a synthetic degradable augmentation device to support the autograft. Knee Surg Sports Traumatol Arthrosc. 2014;22(9):2109-20.
8. Messer T, Cummins C, Ahn, J, Kelikian A. Outcome of the modified Brostrom procedure for chronic lateral ankle instability using suture anchors. Foot Ankle Int. 200;21(12):996-1003.
9. VanDijk C. Posterior ankle impingement. In: VanDijk C, ed. Ankle Arthroscopy. Springer, Berlin, 2014, pp. 231-258.
10. Peterson W, Pufe T, Zantop T, Paulson F. Blood supply of the flexor hallucis longus tendon with regard to dancers tendinitis: injection and immunohistochemical studies of cadaver tendons. Foot Ankle Int. 2003; 24(8):591-596.
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12. Ogut T, Ayan E, Irgit K, Sarikaya A. Endoscopic treatment of the posterior ankle pain. Knee Surg Sports Traumatol Arthrosc. 2011; 19(8):355-1361.

Editor’s note: For a related article, see “Emerging Insights On Surgical Options For Chronic Ankle Instability” in the March 2015 issue of Podiatry Today.