The Use of Far Cortical Locking Constructs for Fixation of Periprosthetic Fractures

Abstract

Locked plate constructs used for fixation of periprosthetic fractures show high rates of healing difficulties. This is especially true in the distal femur, where modern studies show a revision rate of 15% to 22%. The combination of residual fracture gaps created by using biological fixation techniques and the high stiffness of locked plates is thought to result in decreased motion at the fracture site. Concern that the increased stiffness of locked plates contributes to the high nonunion rate lead to changes in the surgical technique (longer working length) and implant materials (titanium). These changes result in plate bending at the fracture site and induce callus at the cortex opposite the plate, with very little callus forming at the cortex near the plate. Far cortical locking (FCL) was developed out of the need to decrease construct stiffness and increase callus formation by allowing symmetric fracture site motion within the optimal range for secondary bone healing. The use of FCL constructs requires only minor changes in surgical technique from standard locked plating. Early outcomes using FCL screws for both nonperiprosthetic and periprosthetic fractures suggest the screws are safe in osteoporotic bone with increased callus formation and no screw breakage or pull out.