Evaluation of a 3-D printed drill guide to facilitate fluoroscopic-assisted Kirschner wire placement for minimally invasive iliosacral screw placement in dog cadavers.

Abstract

To evaluate the ease and accuracy of using a 3-D printed (3-DP) drill guide to insert Kirschner wires through the ilium and into the sacral body in preparation for minimally invasive iliosacral screw placement in dog cadavers. 10 dog cadavers weighing 20 to 30 kg (mean ± SD, 24.5 ± 5 kg). Kirschner wires were placed using a limited approach to the lateral ilium. Fluoroscopy was used in freehand and 3-DP drill guide application groups to facilitate the placement of a 1.0-mm Kirschner wire that was over-drilled using a 2.5-mm cannulated drill bit. Kirschner wires were placed using a 3-DP drill guide on 1 hemipelvis and freehand wire placement was done on the contralateral hemipelvis. Postprocedural CTs were obtained, and 2-D and 3-D analyses were performed. The Student t-test and Wilcoxon rank sum test were used to compare groups. A Pearson correlation coefficient was performed to evaluate the in-group correlation. Likert scores that assessed the ease of the procedure were significantly greater (P = .04) and the incision length was significantly shorter (P = .016) in the 3-DP drill guide group compared with the freehand group. The time of the procedure, the number of attempts to obtain accurate Kirschner wire placement, and fluoroscopy images did not differ (P > .05) between application groups. Drill tracks were primarily confined to the sacral body, with minor projected screw thread cortical breeches occurred in 1 cadaver in the freehand group and 2 cadavers in the 3-DP drill guide group. The 3-DP drill guide simplified appropriate iliosacral Kirschner wire placement through a smaller incision compared with freehand drilling and would appear to be an efficient, practical instrument to facilitate accurate fluoroscopic-assisted screw placement when stabilizing sacroiliac luxations in dogs.