Management Anterior Cruciate Ligament Tibia Spine Avulsion Fracture

Anterior cruciate ligament (ACL) tibial avulsion fractures, also known as tibial eminence fractures, are intra-articular fractures of the bony attachment of the ACL on the tibia. The Meyers and McKeever classification categorizes fractures of the tibial eminence into 3 types. Type I fractures refer to nondisplaced or minimally displaced eminence fractures. Type II fractures indicate that the anterior one-third to one-half of the avulsed bone has been displaced proximally or hinged. Type III fractures refer to complete separation of the avulsed fragments. Rotated and comminuted fractures are identified as type IV. For displaced ACL avulsion fractures, nonoperative treatment commonly results in higher rates of nonunion; therefore, surgical fixation should be considered for these types of fractures. Fixation for avulsion fracture fragments can be achieved by using a variety of implants such as Kirschner wires, sutures, and screws. Among these techniques, arthroscopic fixations with screws or sutures are the current mainstream interventions. In biomechanical performance, the comparative fixation strength between sutures and screws remains inconclusive. Tsukada et al found screw fixation to be superior in obtaining rigid fixation under cyclic loading. Mahar et al showed no clear biomechanical differences, including in failure tensile force and deformation after cyclic loading, between fixation methods using screws and sutures. Other studies concluded that sutures provide more fixation strength than screw fixations. In addition to the biomechanical findings, the clinical results showed contrasting findings for screw fixations and suture fixations used for tibial avulsion fractures. Better pivot-shift performance and shorter operating times were observed in screw-fixation surgical procedures, whereas lower subsequent surgery rate and better functional outcome scores were observed for suture-fixation surgical procedures. The latest clinical study conducted by Callanan et al revealed that suture and screw fixations lead to comparable clinical outcomes. Common complications following treatment are residual laxity, knee stiffness, and nonunion or malunion.