Does calibration technique for distal locking screw insertion reduce radiation exposure and operative time during intramedullary nailing of humeral shaft fractures in comparison with freehand technique?

Purpose: The aim of this study was to compare the influence of two different methods of distal screw insertion during intramedullary nailing of humeral shaft fractures on radiation exposure and operative time. Methods: A single-center retrospective study, which included 44 patients, was conducted. Patients were divided into the Freehand and Calibration groups according to the technique used for distal screw insertion. Medical records were used to collect baseline characteristics of patients and complications, and operative reports were used to collect data for outcomes which included number of expositions, dose area product (DAP), fluoroscopy time and operation time. Operation time was defined as time from skin incision to final suture. Results: There were no significant differences noted between the groups in gender, age, fracture side and fracture type distribution. The mean DAP in the Calibration group measured 232.8 ± 130.1 μGy·m2, and was lower than in the Freehand group where measured value was 305.4 ± 141.6 μGy·m2, without significant difference between the groups (p = 0.084). Mean fluoroscopy time was also lower in the Calibration group of patients (32.3 ± 12.7 s) than in the Freehand group (39.4 ± 14.6 s), with p = 0.094. Mean operative time was shorter in the Calibration group (68.8 ± 27.1 min) in comparison with the Freehand group (76.5 ± 17.7 min), but without statistically significant difference (p = 0.272). Conclusion: The usage of calibration technique for distal locking screw insertion has similar operative time and intraoperative radiation exposure during intramedullary nailing of humeral shaft fractures compared with the freehand technique.