Increased Complication and Hardware Removal Rates with Headed Screws in Ankle or Subtalar Arthrodesis

Abstract

Category: Ankle; Hindfoot Introduction/Purpose: A large variety of hardware can be used for ankle or subtalar (ST) joint arthrodesis, with very little data available to guide which implants might be most effective for these indications. Hardware removal rates in the setting of calcaneal fixation have been shown to vary widely from 9-47%, which can impose an added economic and surgical burden on both the patient and the healthcare system. The purpose of this study was to determine if there was a difference in the outcomes between two different versions of cannulated screws (i.e., headless, variable-pitched; headed), as reflected by patient-reported outcome measures (PROMs), and postoperative complication and reoperation rates. Methods: A retrospective chart review identified 126 patients (135 feet) who underwent ankle or ST arthrodesis with a single fellowship-trained foot and ankle surgeon between December 2015 and February 2021. These patients met the following inclusion criteria: isolated tibiotalar or ST arthrodesis; receipt of a headless, variable-pitched screw made by Acutrak or headed screw made by Orthohelix; and minimum 3 months of postoperative radiographic follow-up. Overall, 76 procedures used headless, variable- pitched screws (ankle=13, ST=63) and 59 used headed (ankle=18, ST=41). Results: Overall, there was a significantly higher rate of complications among headed screws (54.2%), as compared to the headless, variable-pitched screws (35.5%; p =.030). There was no difference in any treatment duration or postoperative PROM between groups. There was a significant difference in reoperation rates between cohorts (headless, variable-pitched=11.8%, headed=32.2%; p =.004), but no difference in nonunion rate (headless, variable-pitched=22.4%, headed=35.6%; p =.090). There were also significantly more screw issues (i.e., break, movement, impingement) with headed screws (headless, variable- pitched=0.0%, headed=5.1%; p =.047). (Table 1) Of the nine patients who underwent a reoperation, headed screws were removed six (66.7%) times, with half attributable to nonunion, whereas headless, variable-pitched hardware was only removed once (1.11%) due to infection. Conclusion: Overall, the use of headed screws in ankle or ST arthrodesis is associated with significantly higher rates of complication and hardware removal, as compared to headless, variable-pitched screws. Even in the examination of the few patients in this cohort who underwent two procedures, headed screws were removed more often. Surgeons should place emphasis on these results when selecting the best hardware to fuse the ankle and ST joints.