Does Surgical Placement of Syndesmosis Screws Affect Breakage Rate? A Retrospective Comparative Study

Category: Ankle Introduction/Purpose: Fixation of syndesmosis disruption with metal screws remains a frequent and efficacious treatment modality. Screw breakage remains a complication seen in many patients following metal fixation. Overtime physiologic rotation or the tibia and fibula can lead to bone erosion and pain in patients with screw breakage. The purpose of this study is to compare patients with syndesmosis screw breakage and patients with intact screws based surgically controlled variables. Methods: A retrospective analysis of patients who underwent syndesmotic screw fixation from 2008 - 2020 was performed. Ninety-seven patients were found to have syndesmosis screw breakage, of which 88 met inclusion criteria. A control group of patients without syndesmosis screw breakage was selected at random and analyzed until 88 patients met inclusion criteria. The number of screws used, width, length, fracture type and number of cortices were all collected. Further analysis included radiographic measurement syndesmosis screw angle and height of placement above the tibial plafond. A regression analysis was performed to compare to the two groups, including a separate analysis comparing unbroken screws within syndesmosis screw breakage cohort versus their broken screws, as this provided an absolute control group. A stratified analysis of screw placement and angle was also performed based on standard deviation. Results: The average screw width in the breakage group was 3.67 (SD =.38) and 4.06 (SD =0.04) in the intact group (P = 20mm above the tibial plafond, compared to 64.0% in the control group. Most screws were placed at angle > 82 degrees relative to the tibial plafond; 76% (n =92) of broken screws and 81.2% (n=211) of intact screws). Decreased screw width (P = 20mm above the tibial plafond (P =