Violation of the Subtalar Joint With Novel Suture Tape Augmentation of Lateral Ligament Reconstruction: A Report of 2 Cases

Introduction

The modified Broström-Gould operation is the gold standard for surgical treatment of chronic lateral ankle instability.^2,4 Modified Broström-Gould repair with the InternalBrace (IB) is a relatively new technique promoted as providing additional biomechanical advantage resulting in early mobility during recovery and quicker return to activity.⁶ Although the IB has a reportedly low complication profile, with the rise in its usage, providers should be aware of potential detrimental complications.⁸ Intra-articular placement of suture anchors is a potential complication warned against in the manufacturer surgical technique videos of the IB; however, to our knowledge, this complication has yet to be reported in the literature.^1,3

In the current article, we present 2 cases of suture anchor violation of the subtalar joint during IB augmentation for lateral ligamentous complex repair of the ankle.

Both patients were informed that the data concerning their cases would be submitted for publication, and both provided verbal consent.

Case Report

Case 1

A 59-year-old active woman presented to an orthopaedic foot and ankle clinic for evaluation of 7 months of chronic left ankle pain after she underwent a modified Broström-Gould with IB augmentation of the CFL with an orthopaedic surgeon for ankle instability. The initial goal of the IB placement was to allow for faster rehabilitation and augment poor-quality tissue. The patient reported that subtalar fusion was discussed, but she preferred to proceed with IB placement, understanding that fusion would still be an available option in the future. Once she was able to weightbear postoperatively, she experienced intense sharp pain in her heel, likened to walking on a broken bone. The pain was exacerbated when walking on uneven surfaces. She was unable to return to her active lifestyle after extensive physical therapy.

Upon examination, she was maximally tender at the subtalar joint, anterior talofibular ligament (ATFL), and distal fibula. Tibiotalar and subtalar range of motion were decreased with significant deficits in eversion and inversion. Sensation and strength were intact throughout. Ligamentous examination with anterior drawer test was stable.

Radiographs of the left ankle revealed an anchor tract adjacent to the subtalar joint with an ossicle at the distal fibula (Figure 1). A magnetic resonance imaging scan from 2 weeks prior to presentation was reviewed and revealed edema and scarring of the ATFL and calcaneofibular ligament (CFL) as well as significant edema in the calcaneus along an anchor tract in the subtalar joint (Figure 2). A computed tomography (CT) scan was ordered and confirmed the presence of a suture anchor across and into the subtalar joint. Additionally, CT revealed an osteochondral defect of the posterior subtalar facet of the calcaneus containing irregular sclerotic ossicles and degenerative cartilage space narrowing at the margins of the posterior subtalar joint (Figure 3). After discussion with the patient, removal of the internal brace, debridement of sinus tarsi, and revision modified Broström-Gould was planned.

Figure 1.

Preoperative weightbearing lateral radiograph of the left ankle with a yellow arrow denoting an anchor tract adjacent to the subtalar joint.

Figure 2.

Sagittal cross-section from a preoperative magnetic resonance imaging scan of the left ankle demonstrating an anchor tract seeming to communicate with the subtalar joint (yellow arrow).

Figure 3.

(A) Two sagittal cross sections from a preoperative computed tomographic (CT) scan of the left ankle demonstrating presence of a suture anchor across and into the subtalar joint. (B) Axial cross-section from preoperative CT scan of left ankle. The yellow arrows in A and B denote the suture anchor.

At the time of surgery, the prior suture anchor was found to be within the subtalar joint and was removed with debridement of surrounding scar tissue. A stable edge of remaining cartilage was established, and microfracture of the lateral posterior facet was performed to try to stimulate fibrocartilage healing. Then, the revision modified Broström-Gould was performed. Anterior drawer and inversion tests found no instability after repair. She was placed in a standard AO-type splint with the ankle held in neutral dorsiflexion to be nonweightbearing for 4 weeks.

Follow-up at 2 weeks and 8 weeks revealed she was doing well. Upon initiation of weightbearing, her pain was improved, and she reported no recurrence of the sensation of walking on a broken structure. She continued to improve throughout her postoperative period. She developed mild plantar fasciitis and Achilles tendonitis in the operative extremity at 8 months postoperatively. These symptoms improved significantly with night splinting and home exercises. At her most recent visit, 10 months after surgery, her plantar fasciitis pain had completely resolved, and her Achilles tendinitis pain had significantly improved. On examination, she had full strength throughout with no instability on anterior drawer or inversion testing. She was walking up to 7 miles a day, participating in Pilates, playing pickleball, and planning to hike Mount Kilimanjaro.

Case 2

A 32-year-old active man presented for evaluation of right ankle pain. He had ankle instability for over half of his life with multiple ankle sprains requiring surgical repair. Two years prior to presentation, he had a particularly severe ankle sprain. He reported evaluation by a podiatrist who recommended surgery for ankle ligamentous repair and bunion correction. He underwent right lateral ligament stabilization and Lapidus bunion surgery with the goals of stabilizing the ankle and relieving pain from his bunion. Ten months later, he presented for a second opinion with sharp pain over the anterior aspect of his right ankle that occasionally radiated up to his knee, as well as recurrence of his bunion deformity with associated pain over the first metatarsal head and tarsometatarsal (TMT) joint. At this time, his ankle pain was exacerbated when going down stairs, requiring him to take steps one at a time. He described the sensation of constant pressure over the top of his ankle. He was weightbearing in a sneaker, and his limp progressively worsened, with more discomfort during pivoting motions.

Physical examination revealed maximal tenderness to palpation at the subtalar joint. There was mild stiffness at the subtalar joint, but tibiotalar joint motion was preserved. Sensation and motor examinations were intact. There was stability with anterior drawer and inversion tilt with no pain or apprehension. There was a positive Tinel sign over the terminal branches of the superficial peroneal nerve.

Radiographs of the right foot and ankle revealed prior Lapidus with nonunion of the first TMT with recurrence of deformity and evidence of an anchor tract in the talus (Figure 4). CT revealed a talar anchor tract that violated the subtalar joint. A magnetic resonance imaging scan of the right foot and ankle revealed a complete tear of the ATFL, degenerative changes of the posterior talofibular ligament, and an intact CFL. There were arthritic changes at the posterior subtalar joint with cystic changes and bony edema near the lateral side of the subtalar joint (Figure 5).

Figure 4.

(A) Preoperative weightbearing anteroposterior radiograph of the right ankle. (B) Preoperative weightbearing lateral radiograph of the right ankle. Yellow arrow denotes anchor tract adjacent to the subtalar joint. (C) Preoperative weightbearing anteroposterior radiograph of the right foot showing nonunion of the first tarsometatarsal with recurrence of hallux valgus deformity.

Figure 5.

Sagittal cross section from a preoperative magnetic resonance imaging scan of the right ankle showing bony edema near the lateral side of the subtalar joint.

White blood cell count, erythrocyte sedimentation rate, and c-reactive protein (CRP) levels were within normal limits, lowering suspicion for an infectious cause of nonunion. After discussion with the patient, surgical treatment was planned for revision of the Lapidus with calcaneal bone graft and revision modified Broström-Gould with IB augmentation. However, given the concern for complex regional pain syndrome, he was started on gabapentin and referred to physical therapy for nerve desensitization prior to revision surgery.

Intraoperatively, after completion of the bunion revision, attention was turned to the lateral ankle. After dissecting down to the subtalar joint, 2 loose suture anchors with the suture tape attached were identified and removed from within the soft tissue of the lateral ankle. There was significant surrounding scarring and hyperactive inflammatory tissue, with only small remnants of the AFTL and CFL. Suture anchors were used to repair the ATFL and CFL with IB augmentation of the ATFL. Finally, the Gould modification was conducted to complete the repair.

Based on the imaging, symptoms, and intraoperative review, there is strong support for the inappropriate placement of the talar IB suture anchor at the time of the patient’s initial surgery. The imaging findings and location of the suture anchor seen intraoperatively raise suspicion that the drill used to place the anchor was positioned too inferiorly in the lateral process of the talus by the initial surgeon.

Postoperative regimen included standard AO-type splint with transition to a cast at 2 weeks and nonweightbearing for 8 weeks because of the revision midfoot fusion.

The patient was most recently seen 13 months postoperatively. He reported resolution of his midfoot pain with persistent lateral ankle pain. Examination revealed excellent eversion strength and stability with anterior drawer testing, no tenderness over the first ray or first metatarsophalangeal joint, and mild tenderness above the lateral malleolus at the level of the ankle mortise and over the sinus tarsi. He has continued to work with physical therapy.

Discussion

Treatment of chronic ankle instability with the modified Broström-Gould technique has satisfaction rates as high as 96%.⁵ Further augmentation with IB has shown excellent results with no major differences in complications.⁸ However, Wittig et al⁸ noted an increase in occurrence of peroneal nerve and tendon irritation with IB augmentation compared with Broström repair alone in a systematic review of clinical trials, and Pellegrini et al⁷ reported 2 implant failures without compromise of construct stability in a prospective study of 13 patients who received IB augmentation of the deltoid ligament. In this report, we present 2 cases of a major complication where placement of the suture anchor during lateral ligamentous IB augmentation violated the subtalar joint, leading to early arthritic changes.

A thorough understanding of the anatomy and procedure is essential to prevent the occurrence of subtalar joint violation when using the suture anchor. The IB acts as a checkrein that consists of collagen-coated long-chain polyethylene suture tape and fully threaded knotless suture anchors. When augmenting the ATFL, a talar drill hole is created for placement of the suture anchor preloaded with suture tape. After performing the Broström, a fibular hole is created for placement of another suture anchor tensioning the suture tape. Augmentation of the CFL can be done in conjunction with the ATFL or an isolated repair may be performed. In case 1, the IB was used to augment only the CFL. In the company’s surgical technique video on CFL augmentation, it is emphasized to avoid drilling in a lateral to medial direction but to aim slightly inferior and posterior to avoid violating the subtalar joint. It is important to have appropriate exposure of the calcaneus for the starting point for the calcaneal anchor. The peroneal tendons must be sufficiently retracted to ensure that they are not blocking the position of the drill and impacting the trajectory. In case 2, the IB was used to augment the ATFL alone. The error was in the anchor placement of the talus as imaging revealed an anchor in the lateral process of the talus entering the posterior facet of the subtalar joint, likely a result of starting too inferiorly in the lateral process of the talus. The correct starting point should be in the body of the talus at the insertion point of the ATFL with the trajectory of the Talus Offset Drill Guide approximately 40 to 45 degrees from the sagittal plane and parallel with the longitudinal line of the foot. By using the correct starting point in the talar body rather than the lateral process, there is a decreased risk of violating the subtalar joint. To help reduce the risk of violating the joint space, guidewires can be used to plan the location of the suture anchors prior to overdrilling with a cannulated drill. This is applicable to IB augmentation of both the CFL and the ATFL and is a good option as it comes readily available in the IB system. First, K-wires are placed in the appropriate locations in the fibula, talus, or calcaneus depending on the procedure. Fluoroscopy is used to ensure that the K-wires are extra-articular in multiple planes. A cannulated drill is used to overdrill the K-wires and the position is once again checked with fluoroscopy to ensure that the drill bit is extra-articular. The suture anchor can then be placed with a decreased risk of joint space violation. Although this technique is more time intensive, it helps reduce the risk of complication and is particularly useful for surgeons just starting to use the IB technique or when using the IB system for indications other than the standard ATFL reinforcement.

Summary and Conclusion

The modified Broström-Gould technique is a highly successful procedure for lateral ankle instability stabilization. Augmenting with an internal brace may provide additional stability, but the risks and indications of this procedure are not yet fully defined. In the 2 cases presented, the subtalar joint was found to be violated from previous lateral ligamentous complex repair with IB augmentation. Both underwent successful revision surgery, but the subtalar joint damage was permanent. It is the surgeon’s responsibility to be familiar with the anatomy and equipment used in an elective procedure to prevent permanent and potentially lifelong complications for the patient.