Anatomic Feasibility of Distal Fibula Bicortical Screw Fixation With Lateral Neutralization Plating for Rotational Ankle Fractures

Abstract

A common technique for fixation of rotational fibular fractures is to use an interfragmentary compression screw with a laterally positioned neutralization plate. The objective of the present investigation was to examine the anatomic feasibility of distal fibula bicortical fixation within this plating technique. A specific screw insertion technique was performed through a laterally positioned one-third tubular plate on a consecutive series of 81 intact cadaveric ankle mortises. The most distal plate hole was drilled, aimed 10° posterior to the midline of the fibula. The second-most distal plate hole was drilled, aimed 25° superiorly. The specimens were then dissected, and the screw termini were physically examined for whether they had penetrated the articular cartilage of the ankle mortise. The length of the most distal bicortical screw measured a mean ± standard deviation of 20.44 ± 2.49 (range 14 to 26) mm, with an extra-articular terminus in 95.06% of specimens. The length of the second-most distal bicortical screw measured a mean ± standard deviation of 19.68 ± 3.02 (range 12 to 28) mm, with an extra-articular terminus in 100% of the specimens. The results of the present study provide evidence that bicortical distal fibular fixation in accordance with basic fixation principles is anatomically possible and feasible with a one-third tubular plate. This could potentially obviate the need for more expensive fixation options (i.e., locked plates or anatomically contoured plates) and fixation options that are biomechanically stable but potentially anatomically impeding (i.e., posterior antiglide plating).