Prospective observational analysis of intraoperative radiation exposure with a mini C-arm intensifier in percutaneous forefoot surgery

Introduction: Percutaneous forefoot surgery has been associated with higher radiation exposure than the conventional approach. However, there is little data on forefoot surgery using a mini C-arm intensifier. We, therefore, conducted a prospective study to (1) evaluate the intraoperative radiation received by the surgeon during percutaneous forefoot surgery with a mini C-arm; (2) compare the radiation received by the surgeon with the guidelines for occupational exposure issued by the International Commission on Radiological Protection (ICRP) (20 millisieverts per year [mSv/year] for the whole body, 500mSv/year for the hands, and 20mSv/year for the lens of the eye); and (3) compare the radiation received during percutaneous forefoot surgery with that of the open approach, which has already been reported in the literature.

Hypothesis: The radiation received by the surgeon during percutaneous forefoot surgery with a mini C-arm is lower than the ICRP guidelines, and the findings reported in the literature.

Materials and methods: This prospective single-center study was conducted from September 2020 to May 2021. A total of 639 feet (i.e., 435 patients) were included. Of these 639 feet, 336 (52%) were hallux valgus repairs, 49 (8%) were stand-alone procedures of the lateral rays, and 124 (19%) were a combination of both. The radiation dose data was retrieved from the mini C-arm daily: dose-area product (DAP) in centigray per square centimeter (cGy/cm²) and radiation exposure duration in seconds. The doses received by the surgeon were collected every month by 4 passive dosimeters (hand, eye lens, and chest [on and under the lead apron]) and 2 active dosimeters (on and under the lead apron).

Results: The DAP emitted by the mini C-arm during an operating day was 0.10±0.01cGy/cm² (range, 0.0-3.9), and the mean daily radiation duration was 34.7±19.3seconds (range, 0.7-226.8). There was a mean of 8±8 (range, 1-18) elective procedures per operating day. The daily reading on the active dosimeter worn on the lead apron was 0.002±0 microSv (range, 0-0.04), while the one worn under the apron was 0.001±0 microSv (range, 0-0.03). The equivalent doses over the 7-month study period for the hand, eye lens, and chest (over and under the apron) were 0.14mSv, 0mSv, 0.22mSv, and 0mSv, respectively.

Discussion/conclusion: The radiation exposure in percutaneous forefoot surgery with a mini C-arm intensifier observed in our study was lower than the ICRP recommendations and literature findings during open surgery.

Level of evidence: IV; prospective study without a control group.