Estimation of patient dose and associated radiogenic risks from limb lengthening.

UNLABELLED: Limb-lengthening procedures include a series of radiographic examinations to follow the lengthening process and callus formation. We quantified ionizing radiation exposure during lengthening treatment and estimated the risks associated with this exposure in 53 patients undergoing lengthening procedures. Field size and tube voltage of all radiographs and fluoroscopy time during surgery were recorded. According to conversion factor tables of organ doses, the cumulative organ dose was estimated. Location of lengthening, age, complications during lengthening procedure, range of lengthening, healing index, and other factors affecting the duration of the lengthening procedures were analyzed. Average lengthening was 4.8 cm (range, 3.0-12.5 cm). The average cumulative organ dose for a straight lengthening procedure was 3.1 mSv (range, 0.2-12.5 mSv). The average organ dose per centimeter of lengthening was 0.7 mSv/cm (range, 0.03-5.9 mSv/cm). Doses for patients with tibial lengthening (0.3 mSv/cm) were less than doses for patients with femoral lengthening (1.1 mSv/cm). Age, complications, range of lengthening, and healing index did not influence the dosage of radiation per centimeter lengthening. We judge the average patient's exposure during a limb-lengthening procedure as tolerable, but femur lengthening results in a higher cumulative organ dose. LEVEL OF EVIDENCE: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.