EXPERIMENTAL-STUDY OF DISTAL INTERLOCKING OF A SOLID TIBIAL NAIL - RADIATION-INDEPENDENT DISTAL AIMING DEVICE (DAD) VERSUS FREEHAND TECHNIQUE (FHT)

Objectives: Recently, radiation-independent aiming devices for the tib ia that compensate for insertion-related implant deformation have been developed, but the benefits of such systems have not been determined. This study prospectively evaluated the duration of the nailing proced ure, the length of radiation time, and the accuracy of interlocking sc rew placement when using a radiation-independent distal aiming device (DAD) versus the freehand technique (FHT). Materials and Methods: In a n oblique cadaveric tibial fracture, a surgeon inexperienced in both t echniques (DAD and FHT) performed statically locked intramedullary nai ling. Results: For the DAD and the FHT, respectively, the total operat ion time was 25.4 +/- 11.3 (mean +/- standard deviation) versus 30.9 /- 14.3 minutes (p = 0.029), the distal locking time was 16.7 +/- 8.6 versus 21.9 +/- 10.5 minutes (p = 0.004), the total fluoroscopy time w as 9 +/- 5 versus 93 +/- 34 seconds (p < 0.0001), the distal locking f luoroscopy time was zero versus 88 +/- 33 seconds (p < 0.0001), and th e screw wear was -0.7 +/- 5.2 versus 26.8 +/- 31.6 micrometers (p = 0. 001). The failure rate was 1.6 percent tone of sixty screws) in both g roups. Conclusion: These results suggest that the DAD can eliminate th e need for radiation during placement of distal interlocking screws.