Radiation Exposure During Operative Fixation of Pediatric Supracondylar Humerus Fractures: Is Lead Shielding Necessary?

BACKGROUND

Factors that impact radiation exposure during operative fixation of pediatric supracondylar humerus (SCH) fractures have been investigated; however, no studies have measured the equivalent dose at the patient's radiosensitive organs. Our hypothesis was that intraoperative fluoroscopy exposes pediatric patients to a significant radiation load and lead shielding of radiosensitive organs is important. The goal of the study was to quantify the patient's radiation exposure during the procedure by measuring the radiation load at the thyroid and gonads.

METHODS

A prospective quality improvement project of radiation exposure during percutaneous fixation of isolated SCH fractures was performed over a 4-week period. The c-arm image intensifier was used as the operating table and radiation dosimeters were positioned over the thyroid and gonadal lead shields. Fluoroscopy times were recorded, doses were calculated, and the dosimeters were analyzed. To assure that the prospective cohort was representative of a larger population of SCH fractures, demographics and fluoroscopy time of the prospective cohort were compared with a 12-month retrospective cohort in which dosimetry was not performed.

RESULTS

Prospective cohort-18 patients with type 2 (8) and type 3 (10) fractures were prospectively studied with intraoperative measurement of thyroid and gonadal radiation equivalent doses. Mean age was 4.9 years (1.9 to 9.5 y) and mean weight was 21.4 kg (13.1 to 33.5 kg). Mean fluoroscopy time was 65.0 seconds (25.3 to 168.4 s), and absorbed skin dose at the elbow was 0.47 mGy (0.18 to 1.21 mGy). The radiation dosimeters overlying the thyroid and gonads measured minimal radiation indicating equivalent doses of <0.01 mSv for all patients in the prospective cohort.Retrospective cohort-163 patients with type 2 (60) and type 3 (103) fractures were retrospectively studied. The mean age was 5.5 years (0.02 to 13.7 y) and weight was 21.6 kg (2.0 to 71.9 kg). Mean fluoroscopy time was 74.1 seconds (10.2 to 288.9 s), and absorbed skin dose at the elbow was 0.53 mGy (0.07 to 2.07 mGy).There were no statistically significant differences between the cohorts.

CONCLUSIONS

The smaller prospective cohort had fluoroscopy times and radiation doses that were not statistically different from the larger retrospective cohort, suggesting that the dosimeter measurements are representative of intraoperative radiation exposure during fixation of pediatric SCH fractures. The equivalent dose to the thyroid and gonads was minimal and approximates daily background radiation. Shielding of radiosensitive organs is appropriate when practical to minimize cumulative lifetime radiation exposure, particularly in smaller patients and when longer fluoroscopy times are anticipated.

LEVEL OF EVIDENCE

Level 2.