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

Background: This study aimed to evaluate and compare stiffness and load to failure values of a novel medial malleolus compression plate (MP) and a 3.5-mm one-third tubular plate (TP) in the treatment of vertical shear fractures of the medial malleolus.

Methods: Fourteen identical synthetic third-generation composite polyurethane bone models of the 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 a novel MP was applied to bone models in the MP group and a TP was applied in the TP group. All of the samples were evaluated biomechanically, and force/displacement and load to failure values were recorded.

Results: The force required to create displacement in the MP group was twice of that in the TP group. There was a significant difference between the two groups in all of the amounts of displacement (P = .006, P = .005, P = .007 and P = .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 MP is biomechanically higher than that with the one-third semi-TP.