Esther Blanco-Perez

Difficulties in distinguishing between an atlas fracture and a congenital posterior atlas arch defect in postmortem analysis.

We found one atlas from a sample of 148 skeletons (0.67%) that presented different anatomical variations which made it difficult to determine whether the vertebra had an atlas fracture, an unusual Type B posterior atlas arch defect, or a combination of both. We carried out a stereomicroscopy, radiographic, and computerized tomography scan study that revealed that the dry atlas we found presented a very uncommon congenital Type B posterior atlas arch defect, simulating a fracture. In short, the present paper has revealed that differentiating Type B posterior atlas arch defects from fractures in post-mortem dry vertebrae is more difficult than expected. Thus we believe that it can be easier than expected to mistake Type B posterior arch defects for fractures and vice versa in postmortem studies.

Analysis of the relationship between the double transverse foramen and the possibility of developing clinical symptoms after whiplash

Currently, there is no information about the possibility of developing clinical symptoms after whiplash in double transverse foramen subjects. Our aim was to test whether subjects with double transverse foramen have an increased risk of presenting with an acute headache, dizziness, vertebral artery dissection, and vomiting after whiplash.We recorded the absence/presence of double transverse foramen, and the absence/presence of neck pain, acute headache, dizziness, vertebral artery dissection, and vomiting in 85 patients who had suffered whiplash injuries in car rear‐end impacts in road traffic accidents. We used the odds ratio test to determine whether double transverse foramen subjects are at a higher risk of developing an acute headache, dizziness, and vomiting than non‐double transverse foramen subjects.Although double transverse foramen subjects presented with more clinical symptoms after whiplash, the odds ratio test revealed that their risks of developing acute headache (P = 0.30), dizziness (P = 0.09), or vomiting (P = 0.18) were not significantly greater than in the control group.Double transverse foramen subjects are not at a higher risk of presenting acute headache, dizziness, vertebral artery dissection, and vomiting after whiplash. Clin. Anat. 30:761–766, 2017.

Cortical bone thickening in Type A posterior atlas arch defects: experimental report

BACKGROUND CONTEXT To date, no information about the cortical bone microstructural properties in atlas vertebrae with posterior arch defects has been reported. PURPOSE To test if there is an increased cortical bone thickening in atlases with Type A posterior atlas arch defects in an experimental model. STUDY DESIGN Micro-computed tomography (CT) study on cadaveric atlas vertebrae. METHODS We analyzed the cortical bone thickness, the cortical volume, and the medullary volume (SkyScan 1172 Bruker micro-CT NV, Kontich, Belgium) in cadaveric dry vertebrae with a Type A atlas arch defect and normal control vertebrae. RESULTS The micro-CT study revealed significant differences in cortical bone thickness (p=.005), cortical volume (p=.003), and medullary volume (p=.009) values between the normal and the Type A vertebrae. CONCLUSIONS Type A congenital atlas arch defects present a cortical bone thickening that may play a protective role against atlas fractures.

The torso integration hypothesis revisited in Homo sapiens: Contributions to the understanding of hominin body shape evolution

OBJECTIVES Lower thoracic widths and curvatures track upper pelvic widths and iliac blades curvatures in hominins and other primates (torso integration hypothesis). However, recent studies suggest that sexual dimorphism could challenge this assumption in Homo sapiens. We test the torso integration hypothesis in two modern human populations, both considering and excluding the effect of sexual dimorphism. We further assess covariation patterns between different thoracic and pelvic levels, and we explore the allometric effects on torso shape variation. MATERIAL AND METHODS A sex-balanced sample of 50 anatomically connected torsos (25 Mediterraneans, 25 Sub-Saharan Africans) was segmented from computed tomography scans. We compared the maximum medio-lateral width at seventh-ninth rib levels with pelvic bi-iliac breadth in males and females within both populations. We measured 1,030 (semi)landmarks on 3D torso models, and torso shape variation, mean size and shape comparisons, thoraco-pelvic covariation and allometric effects were quantified through 3D geometric morphometrics. RESULTS Females show narrow thoraces and wide pelves and males show wide thoraces and narrow pelves, although this trend is more evident in Mediterraneans than in Sub-Saharans. Equal thoracic and pelvic widths, depths and curvatures were found in absence of sexual dimorphism. The highest strength of covariation was found between the lowest rib levels and the ilia, and allometric analyses showed that smaller torsos were wider than larger torsos. CONCLUSIONS This is the first study testing statistically the torso integration hypothesis in anatomically connected torsos. We propose a new and more complex torso integration model in H. sapiens with sexual dimorphism leading to different thoracic and pelvic widths and curvatures. These findings have important implications in hominin body shape reconstructions.

Unexpected Persistent Dentocentral Synchondrosis of C2

BACKGROUND The persistence of synchondrosis in adulthood can confound diagnostic decisions made during patient management. CASE DESCRIPTION A 59-year-old woman who presented neck pain, acute headache, and acute cervical myelopathy symptoms after suffering whiplash grade 3 in a car rear-end impact underwent a conventional radiologic study that revealed no fracture and no anatomic spine variations. The magnetic resonance imaging study revealed no spinal cord intensity signal changes, but it showed a persistent (remnant) dentocentral synchondrosis that was undetected in a previous conventional radiographic evaluation. CONCLUSIONS The localization and level of the remnant of the dentocentral synchondrosis are extremely important from the clinical viewpoint because of odontoid and C2 fractures. Neurosurgeons should thus be aware of the possible presence of a persistent (remnant) C2 dentocentral synchondrosis in adult subjects in order to avoid misdiagnosis with C2 fracture.

Can the transverse foramen/vertebral artery ratio of double transverse foramen subjects be a risk for vertebrobasilar transient ischemic attacks?

The C6 is the cervical vertebra into which the vertebral artery enters the passage of the transverse foramen and it is the vertebra most affected by double transverse foramina. There is currently little information about the relation between the vertebral artery and the double transverse foramen in C6. We aimed to test whether subjects with a double transverse foramen in C6 have a reduced transverse foramen/vertebral artery ratio when compared with normal anatomy subjects who possess a single transverse foramen which may be a risk for transient vertebral artery stenosis. We measured the area of the transverse foramen and the vertebral artery in 27 double transverse and 56 normal anatomy subjects using computed tomography angiography. We found significant differences in the area of the transverse foramen between double transverse and normal subjects (P < 0.001) but not between the vertebral artery area of double transverse and normal subjects (P = 0.829). The subjects with double transverse foramina have a reduced transverse foramen/vertebral artery ratio, which may be a possible risk for transient vertebral artery stenosis.