Fetal radiation during acetabular and pelvic ring fixation: Which injury patterns dictate dangerous levels of fluoroscopic cumulative dose.

BACKGROUND: Gravid females with pelvic fractures are rarely encountered by the orthopaedic trauma surgeon. The initial injury can be detrimental to the pregnant patient, but an unnecessary "second hit" from surgery could also contribute to the outcome of the fetus. Understanding the surgical risks for this unique patient population requires knowledge about the negative effects of anesthesia, surgical exposures, and radiation. Radiation levels below 5 rad are negligible to the fetus, while doses above 15 rad significantly increase the harmful fetal effects. The purpose of this study was to identify which pelvis and acetabular fracture patterns dictate dangerous fetal levels a fluoroscopic radiation.

METHODS: All patients greater than 16 years of age with operative or potentially operative pelvic ring, sacrum, or acetabulum fractures treated by a single surgeon during his first five years of practice were screened for inclusion. Included patients underwent open reduction with internal fixation, closed reduction with percutaneous fixation, or exam under anesthesia with a recorded final fluoroscopic cumulative dose, irrespective of pregnancy. Excluded patients had periprosthetic fractures, associated operative femoral head fractures, pathologic fractures, patients undergoing combined ORIF/arthroplasty, revision surgery or hardware removal. Primary outcomes were intraoperative radiation dose per fracture pattern, total cumulative radiation, and miscarriage. Secondary outcomes included demographic information, fracture fixation type, and fluoroscopic radiation per percutaneously placed screw.

RESULTS: One hundred and fifty patients were included in this study. A single eight week pregnant patient with a combined associated both column and anteroposterior compression ring injury was identified who had >5 rad cumulative exposure and a miscarriage during the acute postoperative period. Intraoperative radiation dose differed significantly between elementary and associated acetabular patterns (p = 0.0004). Isolated posterior wall fractures utilized less intraoperative radiation compared to the associated both column and transverse-posterior wall groups. Radiation exposure was less for 2 versus 3 percutaneously placed screws (p = 0.0127), 2 versus 4+ screws (p = 0.0011), but not 3 versus 4+ screws.

CONCLUSION: Increasing fracture complexity influences radiation exposure in pregnant and non-pregnant patients, while demographics had no influence. Isolated posterior wall fractures and 2-screw posterior ring fixation constructs provided consistently safer levels of fluoroscopic radiation. This knowledge can benefit both the surgeon and patient during the shared decision-making process.