Analysis of 28 Broken Syndesmosis Screws

Abstract

Category:Ankle; TraumaIntroduction/Purpose:Syndesmosis screw fixation remains a common standard of care in patients with syndesmosis injuries. Screw fracture is a relatively common occurrence in these patients. The purpose of this is study is to examine the screw characteristics of 28 syndesmosis screws that resulted in screw breakage.Methods:This retrospective study examined all tibia procedures from 2008 to 2019 at a level 1 trauma center. Patients that were treated with a syndesmosis screw that resulted in a screw breakage were included for further analysis. In total, 14 patients satisfied this criterion. A comprehensive analysis of the screw characteristics was then performed. Screw angle was determined using the fibular plate as the vertical axis. Distance of screw fracture also used the fibular plate as a reference point. The tibial plafond was used to determine screw placement. Screws were stratified into subcategories based on standard deviation for screw angle and screw placement.Results:28 screws were analyzed in 14 patients (6 males, 8 females). On average, 2 syndesmosis screws were placed with a range of 1 to 4. Average screw length was 50.54±5.67 (45-65) mm. Average screw width was 3.64±.36 (3.50-4.50). Average angle of screw placement was 88.70±(65.90-99.50). Eighteen (64.29%) of the screws were placed at an angle greater than 90 degrees. Six were between 80-90 (21.42%) degrees. Average height above the tibial plafond was 25.90±(9.75-49.90). Fifteen (53.57%) of the screws were placed between 20-30mm above the tibial plafond. Six (21.43%) were between 10-20 mm. Twelve screw fractures occurred within the fibula, 7 within the tibia, and 2 screws had a fracture within the fibula and tibia. The average fracture distance from the fibular plate was 14.81±2.36(0-36.23) mm.Conclusion:The aim of this study was to examine syndesmosis screw characteristics following fracture. Eighteen of the 28 screws were placed above a 90-degree angle and 15 were placed between 20-30mm above tibia plafond. This may suggest higher risk for screw fracture above 90 degrees and between 20-30mm above the tibial plafond, however, further analysis with more subjects should be done before any determination is made.