A Novel Plate for Vertical Shear Fractures of Medial Malleolus: A Biomechanical Study.

BACKGROUND:This study aims to evaluate and compare stiffness and the load to failure values of our novel medial malleolus compression plate (MP) and 3,5mm 1/3 tubular plate (TP) in the treatment of vertical shear fractures of medial malleolar fractures. METHODS:Fourteen identical synthetic third generation composite polyurethane bone models of right distal tibia were randomly separated into two groups. Fracture models were created with a custom-made osteotomy guide to provide the same fracture characteristics in every sample (AO OTA type 44A2). Fractures were reduced and novel medial malleolus compression plate was applied to bone models in MP group and tubular plate was applied to TP group. All samples were evaluated biomechanically, force/displacement and the load to failure values were recorded. RESULTS:The force required to create displacement in MP group was twice of that of the TP group. There was a significant difference between two groups in all amounts of displacement (p = .006, p = .005, p = .007 and .015 for 0.5, 1.0, 1.5, and 2.0 mm, respectively). CONCLUSIONS:In the treatment of vertical shear fractures of the medial malleolus, the strength of fixation with the novel medial malleolar compression plate is biomechanically higher than the one-third semi-tubular plate.