Buttress Plating versus Anterior-to-Posterior Lag Screws for Fixation of the Posterior Malleolus

Abstract

Category: Trauma Introduction/Purpose: The preferred method of fixation for posterior malleolus fractures remains controversial, and practices vary widely among surgeons. The purpose of this study was to compare anterior-to-posterior lag screws to posterior buttress plating for fixation of posterior malleolus fractures in a cadaveric model. Methods: Posterior malleolus fractures were created in seven pairs of fresh frozen cadaveric ankles. One specimen in each pair was randomly assigned to fixation with either two anterior-to-posterior lag screws or a one-third tubular buttress plate without supplemental lag screws. Each specimen was then subjected to cyclic loading from 0% to 50% of body weight for 5,000 cycles followed by loading to failure. Failure was defined as 1 mm of axial displacement. Results: The buttress plate group showed significantly less peak axial displacement at all time points during cyclic loading. Permanent axial displacement was significantly less in the buttress plate group beginning at cycle 200 (figure). There were no significant differences between the two groups during load to failure testing. Conclusion: Posterior malleolus fractures treated with posterior buttress plating showed significantly less displacement during cyclical loading compared to fractures fixed with anterior-to-posterior lag screws. Surgeons should consider these findings when selecting a fixation strategy for these common fractures. these biomechanical findings. Further research is warranted to investigate the clinical implications of