Increased Complication and Hardware Removal Rates Associated with Headed Screws in Subtalar and Ankle Arthrodeses

Abstract

Category: Ankle; Other Introduction/Purpose: With a reported screw removal rate of 9-47% following subtalar (ST) or ankle arthrodesis, an added economic and surgical burden is imposed on both the patients and the healthcare system. The purpose of this study is to determine if there are any clinical or patient-reported outcome differences between headless, variable-pitched screws and headed screws in ST or ankle arthrodesis. Methods: A retrospective chart review identified 120 patients (128 feet) who underwent ST (n=98) or ankle (n=30) arthrodesis with a single fellowship-trained foot and ankle surgeon at a single academic medical center between December 2015 and December 2020. These patients passed the criteria of excluding those who underwent both arthrodeses simultaneously (i.e., tibiotalocalcaneal arthrodesis) and did not have at least three months of follow-up or postoperative X-rays in their medical record. Overall, 71 procedures used headless screws and 57 used headed screws. Results: There was no difference in any treatment duration or postoperative patient-reported outcome measure between groups. However, there was a significant difference between groups among rates of nonunion (headless=19.7%, headed=35.1%;p=.050), overall complication (headless=33.8%, headed=54.4%; p=.019), reoperation (headless=11.3%, headed=33.3%; p=.002), and hardware removal (headless=4.2%, headed=29.8%; p<.001). There were also significantly more screw issues (i.e., broken, displacement, impingement) with headed screws (headless=0.0%, headed=5.3%; p=.050). Furthermore, of the eight patients who underwent two arthrodeses, headed screws were removed six (37.5%) times, with half attributable to nonunion, whereas headless screws were never removed. Conclusion: The use of headed screws in ST or ankle arthrodesis is associated with significantly higher rates of complication and hardware removal, as compared to headless screws. These results suggest headless, variable-pitched screw fixation for ST and ankle arthrodesis procedures may offer improved outcomes, although further studies should be conducted to confirm this.