Biomechanical evaluation of tibial eminence fractures using suture fixation

This study evaluates the initial fixation strength of tibial eminence fracture repair using 1, 2, 3, and 4 sutures to determine the optimal number of sutures required to adequately secure the avulsed fragment to the tibia. Sixteen skeletally immature porcine knees were stripped of all soft tissues, isolating the femur-anterior cruciate ligament (ACL)-tibia complex. Type III tibial eminence fractures were simulated in the specimens, and each specimen was randomly assigned to a repair group using 1, 2, 3, or 4 #2 FiberWire sutures (Arthrex, Inc, Naples, Florida). Initial fixation strength of the repair was measured by single cycle pull to failure testing using a materials testing machine (Instron, Norwood, Massachusetts). The mean ultimate failure force during anterior tibial translation was 389±128, 627±66, 703±77, and 802±29 N for 1, 2, 3, and 4 sutures, respectively. The lower limit of the 95% confidence interval was >500 N (estimated force of native ACL during activities of daily living) for each group with ≥2 sutures. In this study, at least 2 high-strength sutures were needed for tibial eminence fracture repairs to withstand potential forces seen across the ACL in the postoperative period. Suture fixation of tibial eminence fractures is a reproducible method requiring a minimum of 2 high-strength polyester sutures to resist forces seen during early rehabilitation.