Knotless Arthroscopic Reduction and Internal Fixation of a Displaced Anterior Cruciate Ligament Tibial Eminence Avulsion Fracture
Generally occurring in the 8- to 14-year-old population, tibial eminence avulsion fractures are a common variant of anterior cruciate ligament ruptures and represent 2% to 5% of all knee injuries in skeletally immature individuals. In this article, we report on a new arthroscopic reduction and internal fixation technique that involves 2 absorbable anchors with adjustable suture-tensioning technology. This technique optimizes reduction and helps surgeons avoid proximal tibial physeal damage, procedure-related morbidity, and additional surgery.
Follow-Up
Two weeks after surgery, the patient returned to clinic for suture removal. Four weeks after surgery, radiographs confirmed anatomical reduction of the TEA fracture, and outpatient physical therapy (range-of-motion exercises as tolerated) and isometric quadriceps strengthening were instituted. Twelve weeks after surgery, examination revealed full knee motion, negative Lachman and pivot shift test results, and residual quadriceps muscle atrophy, and radiographs confirmed complete fracture healing with maintenance of a normal proximal tibial growth plate (Figures 10A, 10B).
Discussion
The highlight of this case is the simplicity of an excellent reduction of a displaced ACL-TEA fracture. Minimally invasive absorbable implants did not violate the proximal tibial physis, and the unique adjustable suture-tensioning technology allowed the degree of reduction and ACL tension to be “dialed in.” SutureTak implants have strong No. 2 FiberWire suture for excellent stability with an overall small suture load, and their small size avoids the risk of violating the proximal tibial physis and avoids potential growth disturbances.
Despite the obvious risks it poses to the open proximal tibial physis, surgical reduction of Meyers-McKeever type II and type III fractures is the norm for restoring ACL stability. Screws and suture fixation are the most common and reliable methods of TEA fracture reduction.16,17 In recent systematic reviews, however, Osti and colleagues17 and Gans and colleagues18 noted there is not enough evidence to warrant a “gold standard” in pediatric tibial avulsion cases.
Other fixation methods for TEA fractures must be investigated. Anderson and colleagues19 described the biomechanics of 4 different physeal-sparing avulsion fracture reduction techniques: an ultra-high-molecular-weight polyethylene (UHMWPE) suture-suture button, a suture anchor, a polydioxanone suture-suture button, and screw fixation. Using techniques described by Kocher and colleagues,4 Berg,20 Mah and colleagues,21 Vega and colleagues,22 and Lu and colleagues,23 Anderson and colleagues19 reduced TEA fractures in skeletally immature porcine knees. Compared with suture anchors, UHMWPE suture-suture buttons provided biomechanically superior cyclic and load-to-failure results as well as more consistent fixation.
Screw fixation has shown good results but has disadvantages. Incorrect positioning of a screw can lead to impingement and articular cartilage damage, and screw removal may be needed if discomfort at the fixation site persists.24,25 Likewise, screws generally are an option only for large fracture fragments, as there is an inherent risk of fracturing small TEA fractures, which can be common in skeletally immature patients.
Brunner and colleagues26 recently found that TEA fracture repair with absorbable sutures and distal bone bridge fixation yielded 3-month radiographic and clinical healing rates similar to those obtained with nonabsorbable sutures tied around a screw. However, other authors have reported growth disturbances with use of a similar technique, owing to a disturbance of the open proximal tibial growth plate.9 In that regard, a major advantage of this new knotless suturing technique is that distal fixation is not necessary.
The minimally invasive TEA fraction reduction technique described in this article has 6 advantages: It provides excellent fixation while avoiding proximal tibial growth plate injury; the degree of tensioning is easily controlled during reduction; it uses strong suture instead of metal screws or pins; the reduction construct is low-profile; distal fixation is unnecessary; and implant removal is unnecessary, thus limiting subsequent surgical intervention. With respect to long-term outcomes, however, it is not known how this procedure will compare with other commonly used ARIF methods in physeal-sparing techniques for TEA fracture fixation.
This case report highlights a novel pediatric displaced ACL-TEA fracture reduction technique that allows for adjustable reduction and resultant ACL tensioning with excellent strong suture fixation without violating the proximal tibial physis, which could make it invaluable in the surgical treatment of this injury in skeletally immature patients.
Am J Orthop. 2017;46(4):203-208. Copyright Frontline Medical Communications Inc. 2017. All rights reserved.
