Augmented Lateral Ankle Ligament Reconstruction for Persistent Ankle Instability

Nicholas A. Abidi, MD

Dr. Abidi or an immediate family member has received royalties from Arthrex, Inc.; is a member of a speakers’ bureau or has made paid presentations on behalf of Acumed, LLC; serves as a paid consultant to or is an employee of Acumed, LLC; serves as an unpaid consultant to Wright Medical Technology, Inc.; and has stock or stock options held in Global Orthopaedic Solutions, LLC.

PATIENT SELECTION

Indications

There are up to 27,000 ankle sprains in the United States every day.¹ If evaluated and treated shortly after the initial injury, most sprains can be successfully treated nonsurgically. Patients with persistent ankle pain, locking, giving way, and swelling should be considered for further investigation into the etiology of the symptoms. Older patients with instability of the knee or ankle can fall unexpectedly and sustain wrist and hip fractures. Surgery should not be considered in patients with chronic lateral ankle ligament instability until a course of treatment with ankle bracing treatment and physical therapy has failed. Many of these patients can develop osteochondral defects of the talus, impinging spurs, and tibiotalar joint osteoarthritis.² Surgical reconstruction of the ankle ligaments should be considered before the sequelae of chronic instability develop. Patients with thick, native, attenuated ligaments can be considered for traditional lateral ankle ligament reconstruction.³ Patients with underlying hyperlaxity, more than 10 years of instability, and nonexistent ligaments upon intraoperative inspection or failed prior Broström procedure should undergo tendon or 2 mm nonabsorbable suture-tape augmentation as opposed to simple native lateral ankle ligament reconstruction.⁴^,⁵

Contraindications

There are some contraindications to ankle ligament reconstruction. Patients with significant underlying arthritis should not undergo ankle ligament reconstruction expecting that it would be a definitive procedure. These patients are typically more suitable for arthrodesis or total ankle arthroplasty. Some arthroplasty patients may actually require lateral ankle ligament reconstruction before undergoing total ankle arthroplasty to stabilize the prosthesis. Older patients who cannot participate in rehabilitation are not optimal surgical candidates. In addition, patients with suspected acute posterior tibial tendon rupture would not do well postoperatively. Patients with poor blood supply and previous scar tissue formation laterally should undergo reconstruction along with plastic surgery advice. Neuropathic patients who are at risk of Charcot arthropathy are not acceptable candidates for lateral ankle ligament reconstruction. We will describe lateral ankle ligament reconstruction with native ligaments,⁴ 2 mm nonabsorbable suture-tape augmentation with interference anchors⁵ and peroneus longus tendon strip autograft, or hamstring autograft/allograft.⁶

PREOPERATIVE IMAGING

Stress ankle radiographs have been used in the past as the diagnostic standard for demonstrating ankle instability. However, there are groups of patients who present with functional instability and have negative stress radiographs. Stress ankle radiographs are cumbersome and inaccurate. Commercially available instability devices do not appear to correlate well with clinical ankle instability. In addition, these studies are painful to patients. Studies have pointed out the inconsistencies among MRI, stress radiography, and intraoperative arthroscopic findings.⁷

Weight-bearing radiographs of the foot and ankle are necessary to determine articular space and alignment. Patients with varus tibiotalar joint degenerative changes may not be candidates for lateral ankle ligament stabilization alone (Figure 1). Younger patients with this deformity may be candidates for supramalleolar osteotomy. However, removing periarticular osteophytes can occasionally result in a plantigrade ankle that is amenable to lateral ankle stabilization. Patients with varus heel alignment on examination and plain radiographs may require lateralizing calcaneal osteotomy at the time of lateral ankle ligament stabilization. A lateral foot radiograph may determine that the patient has excessive plantar flexion of the first ray, which might lead to excessive varus moment on the hindfoot and ankle.⁸ This may require dorsiflexion osteotomy of the first metatarsal shaft in addition to the lateral ankle ligament stabilization (Figure 2). MRI of the ankle, preferably in at least a 1.5-T scanner with an extremity coil, provides
images that can evaluate bony surfaces and portions of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL). Most experienced surgeons use MRI to look for unexpected problems in the tendons or joint that require planning and additional attention at the time of surgery. The diagnosis of instability is typically based on a history of instability and the clinical evaluation (Figure 3).

FIGURE 1 CT scan demonstrates medial tibial degenerative joint disease and supramalleolar varus deformity.

VIDEO 86.1 Augmented Lateral Ankle Ligament Reconstruction. Nicholas A. Abidi, MD; Brian Martin, PA-C (25 min)

View Quicktime Video

Video 86.1

FIGURE 2 Postoperative lateral radiograph shows a first metatarsal dorsiflexion osteotomy combined with calcaneal osteotomy.

FIGURE 3 Photograph shows the anterior drawer test. The foot is slightly plantarflexed and internally rotated. The examiner’s right hand stabilizes the tibia while the left hand exerts an anterior pull.

PROCEDURE

Patient Positioning

Patient positioning must take into account procedures that are performed at the same time as lateral ankle ligament reconstruction. I typically perform simultaneous ankle arthroscopy and occasionally fluoroscopy. Patients are placed on a beanbag in a semilateral position. The patient’s feet should be at the end of the operating table to facilitate dorsiflexion of the foot during ligament tensioning at the end of the ligament reconstruction. The range of motion of the hip joint and the leg should be checked to be sure that access will be appropriate for all the planned procedures before prepping and draping. It is important to be able to externally rotate the ankle and leg enough to have access to the medial and lateral ankle arthroscopic portals during the initial phase of the case (Figure 4).

Anesthesia

Patients undergo a popliteal block anesthetic that can be supplemented with a spinal or general anesthetic as necessary. The saphenous nerve should undergo a regional block to manage medial postoperative pain. This can be performed by injecting local anesthetic at the proximal medial calf and distal supramalleolar region to get variable branches of the saphenous nerve. This can also limit pain when using a calf tourniquet.

Surgical Technique

I routinely perform ankle arthroscopy to débride the distal portion of the anterior tibiofibular ligament, the impinging tibiotalar osteophytes, and loose bodies from the anterior tibiotalar joint (Figure 5). In addition, the talus is carefully inspected for osteochondral defects on the medial and lateral talar dome. This is performed
before the open lateral ankle ligament stabilization procedure but during the same surgical session. Detailed ankle arthroscopic technique in the presence of ankle instability will not be described here because the indications and the technique of the arthroscopic procedure in the presence of ankle instability have been described by multiple authors.²^,⁴^,⁵^,⁶^,⁷^,⁸^,⁹^,¹⁰^,¹¹^,¹² The accompanying video outlines ankle arthroscopy in addition to the augmented Broström ligament reconstruction involving a split free peroneus longus tendon autograft. In addition, we have provided new illustrations of 2 mm nonabsorbable suture-tape augmentation of the native lateral ankle ligament reconstruction.

FIGURE 4 Photograph shows setup and patient positioning for lateral ankle ligament reconstruction. The surgical leg is elevated on a foam block. The peroneal nerve of the nonsurgical leg and all bony prominences are shielded from any pressure.

FIGURE 5 Arthroscopic view shows a loose body being removed from the tibiotalar joint.

Technique

Split Peroneus Longus Autograft Augmentation of Lateral Ankle Ligament Reconstruction

An incision is made from 5 cm above the tip of the lateral malleolus, traveling over the midmalleolus and coursing distally over the peroneal tendons toward the base of the fifth metatarsal. During the dissection, the sural nerve is avoided.

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