Medial Locking Plate Can Increase the Fixation Stability of Vertical Femoral Neck Fracture in Young Adults?

Introduction: Vertical femoral neck fractures in young adults are usually caused by high-energy trauma. These injuries are difficult to stabilize due to significant shear forces acting on the fracture site. Their treatment is challenging and with high risks of complications, such as fixation failure, malunion, nonunion, and avascular necrosis of the femoral head. Material and Methods: It compared the biomechanical stability provided by 3 different fixation methods: (1) dynamic hip screw with derotation screw, (2) cannulated screws with a conventional medial bone plate, and (3) cannulated screws with a locked medial bone plate. These fixation structures were applied on fourth-generation medium-sized synthetic bones, with a 17 pound per cubic foot cellular foam core and cervico-diaphyseal angle of 120 degrees were used. The comparison was performed through biomechanical tests under cyclic loading followed by an ultimate load. The interfragmentary movement at the fracture site was the main variable for the cyclical phase. Results: The biomechanical comparison showed no statistical differences (P > 0.05) in stiffness, micromovement level, and mechanical resistance among the fixation techniques evaluated. Discussion: To stabilize the vertical femoral neck fracture in young patients, the use of a medial bone plate associated with cannulated screws on a “tie-rod” assembly is an option that supports the mechanical demand until the fracture healing. The locked medial plate did not provide an advantage compared with the conventional bone plate.