[Effectiveness of lead thyroid shield for reducing roentgen ray exposure in trauma surgery interventions of the lower leg].

The occupational radiation exposure of trauma surgeons has increased over the last few years as a result of biologic orthopaedic procedures like intramedullary nailing as closed reduction and insertion of distal interlocking screws need fluoroscopic control. In order to assess the surface doses of the primary surgeon with and without lead shield of the thyroid we performed in vitro measurements during operative procedures of the lower extremities simulating different intraoperative situations under fluoroscopic control. The average registered ionizing dosage without thyroid shield was 70 times higher compared to the measurements with thyroid protection. In a previous study we found average fluoroscopy times during intramedullary nailing of tibia and femur of 4.6 min per procedure. Extrapolation of this value leads to the result, that even when 1000 intramedullary nailings were carried out without wearing lead protection, 13% of the dose limit recommended by the International Commission on Radiological Protection for the thyroid of 300 mSv per year would not be exceeded, whereas by wearing the lead protection only 0.2% of the recommended dose would be reached.