Montemurro Nicola, Perrini Paolo, Mangini Vittoriano, Galli Massimo, Papini Andrea
1Unit of Neurosurgery, "Di Venere" City Hospital, ASL Bari.
2Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari.
J Neurosurg Spine. 2019 Feb 1;30(5):585-592. doi: 10.3171/2018.9.SPINE18396. Print 2019 May 1.
Odontoid process fractures are very common in both young and geriatric patients. The axial trabecular architecture of the dens appears to be crucial for physiological and biomechanical function of the C1-2 joint. The aim of this study is to demonstrate the presence of a Y-shaped trabecular structure of the dens on axial CT and to describe its anatomical and biomechanical implications.
Fifty-four C2 odontoid processes in healthy subjects were prospectively examined for the presence of a Y-shaped trabecular structure at the odontocentral synchondrosis level with a dental cone beam CT scan. Length, width, and axial area of the odontoid process were measured in all subjects. In addition, measurements of the one-third right anterior area of the Y-shaped structure were taken.
The Y-shaped trabecular structure was found in 79.6% of cases. Length and width of the odontoid process were 13.5 ± 0.6 mm and 11.2 ± 0.9 mm, respectively. The mean area of the odontoid process at the odontocentral synchondrosis was 93.5 ± 4.3 mm2, whereas the mean one-third right anterior area of the odontoid process at the same level was 29.3 ± 2.5 mm2. The mean area of the odontoid process and its length and width were similar in men and women (p > 0.05). No significant difference was found in the mean area of the odontoid process in people older than 65 years (94 ± 4.2 mm2) compared to people younger than 65 years (93.3 ± 4.4 mm2; p > 0.05).
The authors identified a new anatomical entity, named the Y-shaped trabecular structure of the odontoid process, on axial CT scans. This structure appears to be the result of bone transformation induced by the elevated dynamic loading at the C1-2 level. The presence of the Y-shaped structure provides new insights into biomechanical responses of C2 under physiological loading and traumatic conditions.
齿突骨折在年轻和老年患者中都很常见。齿突的轴向小梁结构似乎对C1-2关节的生理和生物力学功能至关重要。本研究的目的是在轴向CT上显示齿突的Y形小梁结构的存在，并描述其解剖学和生物力学意义。
对54例健康受试者的C2齿突进行前瞻性研究，采用牙科锥形束CT扫描在齿突中央软骨结合水平检查Y形小梁结构的存在。测量所有受试者齿突的长度、宽度和轴向面积。此外，还对Y形结构的右前三分之一区域进行了测量。
79.6%的病例中发现了Y形小梁结构。齿突的长度和宽度分别为13.5±0.6mm和11.2±0.9mm。齿突中央软骨结合处齿突的平均面积为93.5±4.3mm²，而同一水平齿突右前三分之一的平均面积为29.3±2.5mm²。男性和女性齿突的平均面积及其长度和宽度相似（p>0.05）。65岁以上人群齿突的平均面积（94±4.2mm²）与65岁以下人群（93.3±4.4mm²；p>0.05）相比无显著差异。
作者在轴向CT扫描中发现了一种新的解剖结构，称为齿突Y形小梁结构。这种结构似乎是C1-2水平动态负荷增加引起的骨转化的结果。Y形结构的存在为C2在生理负荷和创伤条件下的生物力学反应提供了新的见解。
