The Journal of foot and ankle surgery : official publication of the American College of Foot and Ankle Surgeons
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Displaced medial malleolus fractures are considered unstable and typically require open reduction and internal fixation for anatomic reduction and early joint range of motion. These fractures are usually fixated with either compression lag screws or tension band wiring depending on the fracture pattern, size of the distal fragment, and bone quality. When fracture fixation fails, it is typically in pullout strength. ⋯ The median force recorded at 2 mm of distraction using unicortical partially threaded cancellous screws was 116.2 N (range 70.2 to 355.5N) compared with 327.6 N (range 117.5 to 804.3 N) in the fully threaded bicortical screw (P = .04). The unicortical screw fixation displayed only 64.53% of the median strength noted with the bicortical screw fixation at clinical failure. The current study demonstrated statistically significantly greater pullout strength for 3.5-mm bicortical screws when compared with 4.0-mm partially threaded cancellous screws used to fixate medial malleolar fractures in a cadaveric model.