Digital analysis and certification of osseous pathway for anterograde screwing in acetabular posterior column

Abstract

Objective To analyze and determine the optimal osseous pathway for anterograde screwing in the acetabulum posterior column. Methods Recruited for this study were 40 healthy adult volunteers, 20 males and 20 females, aged from 18 to 56 years (average, 34.6 years). Firstly, their abdomen CT scanning images were transformed into Materialise Mimics Innovation Suite 16.0 software to obtain the 3D reconstruction images of the pelvis (.stl file). The Imageware 12.0 software (EDS, USA) was used to produce the optimal osseous pathway for anterograde screwing in the acetabulum posterior column. The diameter and length of the pathway were measured and statistically analyzed. Secondly, after 10 adult fresh pelvic specimens were scanned, the optimal osseous pathway for anterograde screwing in the acetabulum posterior column was determined in the same way as the above. A navigation template for anterograde screwing in the acetabular posterior column was manufactured. The screwing in the posterior column of the acetabulum was conducted using Kirschner wire with the aid of the navigation template. Imaging evaluation was performed after fixation. Results The projection of the safe zone in the acetabular posterior column was irregularly triangle; there were no significant differences regarding the projection size between different ages (P>0.05). The maximum diameter and the maximum length of the left optimal pathway in males were respectively 22.37±1.42 mm and 131.27±3.63 mm, and those of the right optimal pathway in males respectively 23.16±1.39 mm and 129.23±3.27 mm. The maximum diameter and the maximum length of the left optimal pathway in females were respectively 17.58±1.83 mm and 112.56±2.77 mm, and those of the right optimal pathway in females respectively 16.92±1.66 mm and 114.41±2.98 mm. There were no significant differences between the left and right sides for the same item in the same gender (P>0.05).There were significant differences between males and females for the same item in the same side (P<0.05). No penetration into the cortex or the hip joint happened. Conclusion The optimal osseous pathway for anterograde screwing in the acetabulum posterior column can be determined by digital techniques, leading to a simple and safe procedure for the treatment of fractures of the acetabular posterior column. Key words: Acetabulum; Fractures, bone; Fracture fixation, internal; Bone nails; Imaging, three-dimensional