Radiation Exposure in Total Ankle Replacement

Abstract

Background: Radiation exposure from diagnostic imaging procedures is associated with increased cancer risk. No published data currently exist regarding ionizing radiation exposure in total ankle replacement surgery. This study quantified intraoperative fluoroscopic dose and duration during ankle replacement surgery and examined patient and technical factors affecting the level of exposure. Methods: Fifty-five patients underwent ankle replacement using STAR, Salto-Talaris, or INBONE total ankles. Intraoperative fluoroscopic dose and duration, patient demographics, implant design, and accompanying additional procedures were documented for each case. The relationship between each relevant variable and radiation dose and time was determined. Results: The mean fluoroscopic dose and duration for all cases were 1.15 ± 0.84 milliGray per case and 77 ± 34 seconds per case, respectively. There was a positive correlation between the absorbed radiation dose and the duration of fluoroscopy ( r = .50, P < .001). The mean fluoroscopic doses were 1.53 milliGray, 0.99 milliGray, and 0.88 milliGray for INBONE, STAR, and Salto-Talaris prostheses, respectively. Fluoroscopic dose was significantly influenced by implant design ( P = .035), with implants using an intramedullary referencing guide associated with higher radiation doses. After excluding cases requiring additional procedures, the fluoroscopic time and radiation dose associated with intramedullary referencing guide implants continued to exceed those of the other implants, but the differences were no longer statistically significant ( P = .22, P = .09, respectively). Conclusion: The average patient radiation dose during total ankle replacement was approximately one-fifth the recommended maximum yearly radiation exposure. The radiation dose was positively associated with fluoroscopy duration. Among factors controllable by the surgeon, selection of an implant with an extramedullary alignment system and conscious effort to minimize duration of fluoroscopy can reduce harmful radiation exposure and decrease cancer risk in total ankle replacement patients and associated operating room personnel. Level of Evidence: Level III, comparative series.