44 Ligament Augmentation with the Internal Brace Abstract The surgical decision making and considerations when preparing to undertake an anatomic ligament repair with augmentation using the Internal Brace are described in this chapter. The Internal Brace supports early mobilization of the repaired ligament and allows the natural tissues to progressively strengthen. The principle established by this experience has resulted in its successful application to other foot and ankle ligaments including the deltoid, spring and syndesmosis complexes as well as other locations including the knee, shoulder, elbow, and hand. The key benefits relate to reduced surgical morbidity and the avoidance of the detrimental effects of immobilization. This has transformed the patient experience. For over 30 years, the accepted orthopaedic approach to joint instability secondary to ligament injury has been reconstruction with allograft or autograft in both the acute and chronic situation. With the Internal Bracing principles and the evolution of technology, we have been able to successfully return to ligament repair. Keywords: ankle instability, anterior talar fibular ligament, augmentation, Internal Brace, FiberTape Broström discounted nonanatomical repairs in favor of an anatomical repair and recognized crucially that, even in chronic situations, it is possible to utilize the damaged ligament in the repair (Fig. 44.1). Concerns regarding the potential weakness of direct soft-tissue repair were in part addressed by the Gould modification incorporating the free edge of the inferior extensor retinaculum (IER) to reinforce the repair. A spectrum of different approaches and techniques has been described to achieve the goal of tightening the lateral restraining tissues of the ankle joint. Repair of the lateral ligaments utilizing a Broström technique results in a construct initially much weaker than the native ligament. Conversely a high proportion of subjects fail to return to their pre-injury level of sport with more traditional nonanatomical approaches—up to 50% in some papers. Our technique for Internal Bracing has reflected this understanding, focusing on augmenting anatomically the anterior talofibular ligament (ATFL; Fig. 44.2). The detrimental effects of immobilization itself may have been underestimated. Only by restoring equivalent natural strength of the ATFL at time zero can immediate mobilization be encouraged with confidence. It is recommended that surgeons use their preferred Broström technique in conjunction with the Internal Brace to optimize results. The biomechanical strength of the Broström alone is insufficient to confidently support early mobilization. The load to failure was 68 N for anatomical sutures and 79 N for fibula suture anchors; both were significantly weaker than the intact ATFL (161 N) in one recent biomechanical study. The need to augment the repair is clearly recognized by surgeons with a multitude of techniques described. The Broström procedure describes a surgical continuum. The use of the fibula periosteum, IER, or a portion of the peroneus brevis tendon to augment lateral ligament reconstruction has been described by several authors. This may be associated with additional morbidity and still requires postoperative protection. Augmentation of a Broström repair, or its replacement, with an allograft tendon has been advocated in certain situations, for example, failed previous repairs, hyperlaxity, and long-standing instability. A recent paper has compared the strength of a semitendinosus allograft with an intact ATFL and reported similar ultimate load to failure—170 N (allograft) compared to 154 N (intact ATFL). Unfortunately, this dead tissue can attenuate during early remodeling. The Internal Brace augments the Broström repair, ensuring sufficient initial strength of reconstruction to safely mobilize as tolerated. Fig. 44.1 FiberTape attached to a 3.5-mm BioComposite SwiveLock (above) for fibula attachment. 4.75-mm BioComposite SwiveLock (below) to which the FiberTape is attached for talus attachment. The Internal Brace was conceived by one of the authors (GMM) and has been used to augment ligament and tendon repair following injury. The Internal Brace construct comprises the FiberTape and two BioComposite SwiveLock screws. The anatomy and biomechanical properties of the lateral ligament complex and the principles of various associated surgical procedures to restore stability have been validated by Dr. Tom Clanton’s expert research. Clanton and coworkers comprehensively reviewed and published a series of papers from the Steadman Philippon Research Laboratory in Vail, Colorado. These papers concluded that direct soft-tissue fixation to anatomical sutures or bone anchors was not of sufficient strength to support early mobilization (Fig. 44.3). This essential appreciation has helped determine the biomechanical advantages derived from using an augmentation technique to support early mobilization. The mean ultimate load to failure of the Internal Brace–Broström combination (251 N) was significantly higher than the native ATFL (154 N) and concluded that the “ATFL with suture tape augmentation is at least as strong and stiff as the native ATFL at time zero in a fresh-frozen cadaveric model” and that “adding strength to the Broström repair, through the addition of suture tape, may be valuable in patients with generalized ligamentous laxity, in large patients or elite athletes, or when graft reconstruction is not feasible.” Fig. 44.2 Internal Brace mimics anterior talofibular ligament (ATFL) anatomy. Fig. 44.3 Suture anchors alone insufficient to restore native strength of anterior talofibular ligament (ATFL), but the Internal Brace restores native strength at time zero. From a patient’s perspective, we can see few reasons why a patient should be subjected to an unnecessary and potentially dangerous period of immobilization after ligament repair. Initially it was assumed that the benefits of the Internal Brace would be limited to the subgroups listed earlier, but the benefits are even greater for patients with significant comorbidities, for example, the diabetic, the obese, those unable to use crutches safely, or even the acute trauma case. • Most patients present with a history of chronic or recurrent lateral ankle ligament instability and sprains. • Pain usually accompanies the acute sprain, but is not a frequent symptom of ankle instability. • Patients may have tenderness over their ATFL anterior to the distal fibular. • Clinical instability of the ankle should be able to be reproduced through an anterior drawer test and varus mechanical stress test clinically. • Patients should be evaluated for associated conditions such as peroneal tendon dysfunction, cavovarus foot alignment, or osteochondral lesions of the talus (OLT). • Standard weight-bearing radiographs should be evaluated for hindfoot alignment, loose bodies or OLTs in the ankle, old allusion fractures off the fibular, or talar insertions of the ATFL. • Magnetic resonance imaging (MRI) is rarely indicated, except in equivocal cases of functional (nonmechanical) instability, or to evaluate for associated pathologies, particularly when pain is the predominant presenting symptom (more than instability). • Physical therapy for peroneal strengthening and proprioceptive training. • Brace immobilization. • Activity modification. • Any patient undergoing a lateral ankle ligament reconstruction is a candidate for Internal Brace augmentation unless • Restore physiologic strength (load to failure) to the ATFL/lateral ankle ligament. • Allow early weight-bearing and ankle motion. • Allow rapid return to function and minimize muscle disuse atrophy. • Limit immobilization time to diminish risks of DVT (deep vein thrombosis)/pulmonary embolism (Fig. 44.4). The use of the Internal Brace should not been seen as a substitute for an anatomical repair or for less exacting surgical standards in performing a Broström procedure. However, the superior strength of the combined construct allows for earlier mobilization postoperatively. The principle of Internal Bracing to facilitate early mobilization, ligament healing, and restoration of optimal function should and can be applied to all ligaments. The FiberTape has an impressive safety record. It is known to have excellent biocompatibility with over 750,000 inserted over 9 years with 0.0001% reported synovial reactions. • Standard Broström lateral ankle ligament reconstruction. • Initial talar footprint Internal Brace fixation. • Appropriate tensioning of the FiberTape prior to fibular fixation. • Final fibular Internal Brace fixation. Surgery can be performed under general, spinal, or regional anesthetic utilizing either a thigh or calf tourniquet according to surgeon and patient preference. Antibiotics are routinely administered prior to tourniquet inflation.
44.1 Indications
44.1.1 The Internal Brace
44.1.2 Expert Opinion
44.1.3 Clinical Evaluation
44.1.4 Radiographic Evaluation
44.1.5 Nonoperative Options
44.1.6 Contraindications
Active infection at the surgical site.
Allergy or history of reaction to FiberWire or FiberTape material.
44.2 Goals of Surgical Procedure
44.3 Advantages of Surgical Procedure
44.4 Key Principles
44.5 Preoperative Preparation and Patient Positioning
44.5.1 Anesthetic Preparation
Musculoskeletal Key
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