Abstract
The availability and usage of portable image intensifiers has revolutionised routine orthopaedic practice. Many procedures have become simpler, easier, less invasive and less time-consuming. Extensive use of fluoroscopy can, however, result in significant radiation exposure to operating staff. An accumulated dose of 65 (Sv after multiple exposures has been reported to increase the risk of thyroid cancer many years later. Previous studies have shown that it is possible to exceed this dose during various orthopaedic procedures. Though thyroid shields are extensively available most orthopaedic surgeons do not use them. The present study was aimed at measuring the scattered dose to thyroid during DHS/IMHS for neck of femur fractures and IM nailing for long bone fractures and thereby emphasise the need for operating theatre personnel to wear a thyroid shield.
A prospective study of 32 consecutive procedures was carried out. The EDD Unfors dosimeter was used to measure the tissue specific exposure dose to thyroid. Measurements were also obtained from the mobile C-arm fluoroscope unit, which calculated the total number of images and the total dose and duration of radiation for each procedure. Other factors including the grade of surgeon, the total number of theatre personnel wearing the lead gown and/or the thyroid shield and the duration of surgery were also recorded.
In 32 procedures, the dose of 65 (Sv was exceeded 13 times; 8 times during DHS/IMHS and 5 times during IMN. The average thyroid dose was 142 (Sv during IMN and 55 (Sv during DHS. Only 9 of 223 (4%) theatre personnel were using a thyroid shield in spite of its availability. The results suggest that the thyroid is frequently exposed to potentially harmful radiation during these procedures. Strict inclusion of a thyroid shield as a part of routine radiation protection is recommended.
