The atlas has two lateral masses with concavities that match the condyles of the occiput, forming the occipito-cervical articulations and allowing for movement of the skull. C1 lacks a vertebral body, consisting instead of a posterior and anterior arch that encircles the spinal cord, mostly posterior to the dens. This allows for lateral and vertical mobility of the head and upper spine. The atlas, or C1 vertebra, sits just inferior to the occiput and through its articulations with C2 and the occipital condyles joins the skull to the spine. Overall, a bimodal distribution is seen, with individuals aged in their mid-twenties and between 80–84 most at-risk for C1 fractures however, the mean age of diagnosis is 64 years and nearly three-quarters of cases occur in patients over 50 years of age. Pediatric patients with C1 fractures are rare, although the mortality rate among infants with this injury is approximately 16 %. This imbalance is reversed in the elderly where 52 % of patients are female, while in younger patients males account for upwards of 70 % of cases. There appears to be a male preponderance, with men accounting for 57–69 % of all cases. Classically, patients presenting with fractures of the atlas have sustained an injury due to diving into shallow water, falling, or a motor vehicle accident. In addition, violent rotational forces on the head and neck may infrequently cause atlas fractures. Atlas injuries occur due to a traumatic axial load and are typically associated with other damage to the upper cervical spine. ![]() Atlas fractures account for 2–13 % of acute injuries of the cervical spine and 1–2 % of all spinal injuries.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |