Zhenhua Cao; Baoke Su;Wei Wang; Zhijun Li; Haiyan Wang; Xing Wang; Shaojie Zhang; Yidan Wang; Huanhuan Guan; Mingjie Gao; Zhiqiang Wang; Yunfeng Zhang; Xiaohe Li & Yan Wang

This study aimed to examine the differences in bone microarchitecture between different regions of the atlas in 28 dry atlas specimens using micro-CT, in order to explain the mechanism of the predilection sites of atlas fractures from the morphological point of view. A total of 28 dry specimens of intact adult atlas were randomly selected, scanned by micro-CT, and divided into a region from the anterior arch midpoint (AAM) to the lateral masses (LM), a LM region, and a region from the LM to the posterior arch midpoint (PAM). Trabecular thickness, separation, number, connectivity, and structure model index were measured for each of the three regions using the built-in software of the CT scanner. Trabecular thickness was all measured to be 0.11 ± 0.00 mm for AAM to LM, LM, and LM to PAM. Trabecular separation: AAM to LM > LM to PAM > LM. Trabecular number: LM > LM to PAM > AAM to LM. Connectivity: LM > LM to PAM > AAM to LM. Structure model index: LM > LM to PAM > AAM to LM. A lower trabecular number and connectivity and higher trabecular separation were seen in the anterior and posterior arches of the atlas, in which higher fracture rates were reported. By contrast, a higher trabecular number and connectivity and lower trabecular separation were seen in the lateral masses, in which lower fracture rates were reported.

CAO, Z.; SU, B.; WANG, W.; LI, Z.; WANG, H.; WANG, X.; ZHANG, S.; WANG, Y.; GUAN, H.; GAO, M.; WANG, Z.; ZHANG, Y.; LI, X. & WANG, Y. A micro-CT study of different regions of the atlas. Int. J. Morphol., 38(2):477-480, 2020.