The Y-shaped trabecular bone structure in the odontoid process of the axis: a CT scan study in 54 healthy subjects and biomechanical considerations

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>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.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>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.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>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 mm<jats:sup>2</jats:sup>, whereas the mean one-third right anterior area of the odontoid process at the same level was 29.3 ± 2.5 mm<jats:sup>2</jats:sup>. The mean area of the odontoid process and its length and width were similar in men and women (p &gt; 0.05). No significant difference was found in the mean area of the odontoid process in people older than 65 years (94 ± 4.2 mm<jats:sup>2</jats:sup>) compared to people younger than 65 years (93.3 ± 4.4 mm<jats:sup>2</jats:sup>; p &gt; 0.05).</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>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.</jats:p></jats:sec>

Cranio-Vertebral Junction Triangular Area: Quantification of Brain Stem Compression by Magnetic Resonance Images

“…In this study, the authors used the ROC curve to analyze the correlation of the TA and myelopathy and yielded a cut-off value of the TA at 1.36 cm 2 , which yielded sensitivity and specificity of 90.7% and 84.1%, respectively. The advances in surgical instrumentations, techniques, and anatomical details provided better outcomes for the patients with CVJ pathologies [ 25 , 26 ]. This TA cut-off value of 1.36 cm 2 for myelopathy further advanced the management of these patients to provide a critical parameter for surgical timing.…”

Clinical Risk and Overall Survival in Patients with Diabetes Mellitus, Hyperglycemia and Glioblastoma Multiforme. A Review of the Current Literature

“…In the last years, there is a growing interest in the literature about the impact of DM2 and hyperglycemia on clinical outcome in cancer patients. Diabetes and obesity are associated with an increased requirement for surgical procedures throughout life and furthermore diabetes and obesity themselves represent risk factors for several surgical treatments, as they are associated with increased postoperative morbidity and mortality [ 58 , 59 , 60 , 61 , 62 ]. Adverse outcomes include surgical site infections, impaired wound healing, implant failure and medical complications [ 59 ].…”

Triangular-Shaped Odontoid Process With Chiari 1 Malformation Patient

“…The triangular-shaped odontoid process reported here is both thinner and more angled than normal. The mean width of a normal odontoid process is about 11 mm [ 8 , 10 ], whereas our case’s width at its midpoint was only 7.5 mm. The triangular-shaped odontoid process may reduce the stability of the CVJ due to the diminished surface area for its surrounding ligaments to attach.…”

“…However, these details have been disputed. In general, the odontoid process is formed via two laterally separated primary ossification centers that fuse in the midline by the seventh to eighth month in utero [ 8 ]. The midline unified primary ossification center proceeds to grow apart from the body of the axis until its fusion between three and six years of life.…”