Distal femoral fractures usually heal through secondary bony unions, which depend on movement between the fracture fragments. Peri-articular locking plates are commonly used for the fixation of distal femoral fractures, but the rate of nonunion is high, probably due to the stiffness of the structure. Distal cortical locking  screws are designed to allow micromotion of the proximal cortex while maintaining fixation only in the distal cortex.
Despite limited clinical data, these screws have been shown in biomechanical studies to provide excellent segment-to-segment motion, and animal models have shown increased callus formation compared to traditional locking screws. The purpose of this study was to examine the clinical effect of FCL screws on the healing of distal femoral fractures treated with locking structures. In this retrospective case series, 15 patients with distal femoral fractures treated with MotionLoc screws  were analyzed.

The presence of callus and time to healing were assessed on serial radiographs. According to the AO classification system. Bone loss occurred in 2 patients. There are no ununions, and the average union time is 24 weeks. No implant failed, and all 5 open fractures, including 2 with bone loss, healed without intervention. There was 1 reoperation due to hardware pain.

Although this is a small case series, these results are promising. Distal cortical locking screws can address the high nonunion rates associated with distal femoral fractures treated with traditional locking structures. The presence of callus and time to healing were assessed on serial radiographs. According to the AO classification system. Bone loss occurred in 2 patients. There are no ununions, and the average union time is 24 weeks. No implant failed, and all 5 open fractures, including 2 with bone loss, healed without intervention. There was 1 reoperation due to hardware pain. Although this is a small case series, these results are promising. Distal cortical locking screws can address the high nonunion rates associated with distal femoral fractures treated with traditional locking structures. The presence of callus and time to healing were assessed on serial radiographs. According to the AO classification system. Bone loss occurred in 2 patients. There are no ununions, and the average union time is 24 weeks. No implant failed, and all 5 open fractures, including 2 with bone loss, healed without intervention.