Multidetector computed tomography evaluation of origin, V2 segment variations and morphology of vertebral artery.

BACKGROUND: The current study aimed to determine the origin of vertebral artery (VA) on both sides and the levels of entry into respective foramen transversarium (FT), to evaluate possible effects of sex on the entry levels, and to investigate the frequency of VA dominance and VA hypoplasia based on the VA V2 segment. MATERIALS AND METHODS: For this study, archived images of patients undergoing multidetector computed tomography (MDCT) examination of the chest and headneck for various reasons at Gaziantep University Medical Faculty Hospital were reviewed retrospectively. Three-dimensional reconstructions were performed for a total of 644 VA images from 322 patients using Horos software, and VA origin, the level of entry to FT and transverse diameters of both VA and FT were measured at the point of entry. RESULTS: It was found that, among males, the VA originated from the truncus brachiocephalicus on the right side in only 1 patient and from the aortic arch in 2 patients on the left side. Left VA emerging from the aortic arch was observed in 2 females. The right VA was found to enter the FT at C3 in 1 male, at C4 in 6 patients (5 males, 1 female), at C5 in 19 patients (3 males, 16 females), and at C6 in 300 patients (141 males, 159 females). The left artery entered the FT at C5 in 23 patients (9 males, 14 females) and at C6 in 298 patients (141 males, 157 females). Looking at the relationship between variations of VA origin and the levels of entry to the FT, it was observed that only one of the left VAs originating from the arcus aorta entered the FT at C6 and at C5 in all others. On the right side, there was only one VA originating from the truncus brachiocephalicus, which entered the FT at C3. Of the remaining 248 VAs originating from the subclavian artery, 5 VAs entered the FT at C4, 14 VAs at C5 and 229 VAs at C6. The measurements of VA diameters showed right VA hypoplasia in 14 patients and left VA hypoplasia in 17 patients. Also, the right VA dominance was found in 110 patients and the left VA dominance in 128 patients. A moderate, positive correlation was observed between VA and FT diameters in both sides. A regression analysis showed that a 1 mm change in the right VA diameter was associated with a 75% change in the FT diameter and a 1 mm change in the left VA diameter caused a 72% change in the FT diameter. CONCLUSIONS: An understanding of VA variations and FT morphometry is crucial for informed clinical practice. This will clearly affect the success rates of physicians in the diagnosis and treatment of pathologies involving cervical region. The presence of any VA variation in a patient should be investigated on computed tomography or magnetic resonance imaging images prior to surgery.

Anatomical Variation and Morphometric Study on Foramen Transversarium of the Upper Cervical Vertebrae in the Thai Population.

STUDY DESIGN: Foramen transversarium (FT) and foramen arcuale (FA) of upper cervical vertebrae (C1 and C2) in the Thai population were investigated for variation and morphometry. PURPOSE: This study aimed to reveal the morphometry of FT and FA in the Thai population. OVERVIEW OF LITERATURE: The FT and FA are structures found in the upper spine that support the vertebral neurovascular system. Clinically, the surgical approaches to achieve upper cervical stability can be affected by spine variations. FT and FA morphometries have been documented to vary by nationality. However, such reports have been limited in the Thai population. METHODS: The FT and FA of dried C1 and C2 vertebrae (identified bones; n=107, males=53 and females=54) were observed and measured using a Digital Vernier Caliper (Mitutoyo, Kawasaki, Japan). Anteroposterior (AP) and transverse diameters of the left and right FTs (n=214) were measured and compared between sexes. Variations and types of FT and FA found on the upper vertebrae were recorded and classified. RESULTS: The FT shape of the Thai C1 was AP elliptical, while of that of C2 was transverse elliptical. Compared to females, both diameters of the upper spine were significantly greater in males except for the AP diameter of C2 on the right side. All diameters were significantly different in both sexes and sides except for the AP diameter of C1 and C2. A common type of FT classified in C1 was type 2 (male [69.81%], female [79.63%]) whereas for C2 it was type 1 (male [63.21%], female [59.26%]). Moreover, an incomplete osseous bridge was a major FA subtype observed in the Thai spine. CONCLUSIONS: FT morphometry has an elliptical shape and diameters are greater in males. The FT and FA variations identified in this study will be useful for surgeons treating vertebral neurovascular injuries of the posterior upper cervical spine in the Thai population.

Morphometric study of foramina transversaria in Jordanian population using cross-sectional computed tomography.

Foramina transversaria are bilateral landmarks of human cervical vertebrae. Morphometric analysis of foramina transversaria is valuable in both clinical and academic fields. This study aims to build a novel normative database of the dimensions of foramina transversaria in Jordanian population and to correlate these data with gender and age. For this purpose, axial computer tomographic images of cervical vertebrae of 329 normal individuals were obtained from the Radiology Department at King Abdulla University Hospital. Cases were subdivided into adolescence, youth, and adulthood groups for both genders. Antero-posterior and transverse diameters were measured bilaterally at all cervical vertebral levels. Statistical analysis of measured dimensions was performed using Statistical Package of Social Sciences software. The results showed that the overall mean antero-posterior diameter of foramina transversaria was 6.09 ± 0.60mms and 5.94 ± 0.62mms on the left and on the right sides, respectively. The corresponding mean transverse diameter measured 4.76 ± 0.51mms and 4.62 ± 0.52mms on the left and the right sides, respectively. Foramina transversaria were significantly larger in males compared to females (p = 0.00). Age-related differences were statistically significant for both antero-posterior and transverse diameters in favor of adult age-group, irrespective of vertebral level. The relevance of these findings is discussed.

Morphometric study of dried cervical vertebrae / Estudio morfométrico de vértebras cervicales secas

The aim of this study was to emphasize the clinical importance of morphometry and the surgical parameters of the cervical vertebrae. The present study was carried out on ninety six adult dry cervical vertebrae (C3-C7, 96) of unknown gender of Turkish population. The various dimensions of the cervical vertebrae (from C3 to C7) were measured with using a digital caliper accurate to 0.01 mm. Linear parameters including vertebral body anteroposterior width (14.03 mm), vertebral body transverse width (24.45 mm); vertebral body height (10.64 mm); pedicle length (R:5.65±1.91 mm, L:5.65±1.76 mm); pedicle width (R:3.72 mm, L:3.61 mm); lamina height (R:9.87 mm, L:9.86 mm); lamina transverse length (R:13.41 mm, L:13.49 mm); superior articular process anteroposterior width (R:7.26 mm, L:7.46 mm); superior articular process transverse diameter (R: 9.87 mm, L:9.58 mm); superior articular process height (R:16.41 mm, L:16.08 mm); inferior articular process anteroposterior width (R: 7.67 mm, L:7.44 mm); inferior articular process transverse diameter (R: 10.32 mm, L:10.09 mm); inferior articular process height (R:12.72 mm, L:12.67 mm); spinous process length (17.91 mm); uncinate process width (R:4.37 mm, L:3.78 mm); uncinate process height (R:4.58 mm, L:3.93 mm); uncinate process length (R:9.28 mm, L:9.12 mm); vertebral foramen anteroposterior width (13.85 mm); vertebral foramen transverse diameter (20.88 mm); foramen transversarium anteroposterior width (R:4.23 mm, L:4.28 mm); foramen transversarium transverse diameter (R:4.78 mm, L:4.95 mm) were measured. Additionally, the distance of the apex of the uncinate process to foramen transversarium (R:2.91 mm, L:2.70 mm), and the distance of the apex of the uncinate process to intervertebral foramen (R: 5.77 mm, L:5.66 mm) were also calculated. There were found significant differences between two sides in the uncinate process width and height, and distance between uncinate process and foramen transversarium. Present measurements suggest that parameters relevant cervical vertebrae can be used as reference and anatomical landmark for evaluating pathologic changes and minimizing complications in the cervical spine.

El objetivo de este estudio fue enfatizar la importancia clínica de la morfometría y los parámetros quirúrgicos de las vértebras cervicales. El presente estudio se realizó en noventa y seis vértebras cervicales secas adultas (C3-C7) de sexo desconocido de la población turca. Las diversas dimensiones de las vértebras cervicales (C3 a C7) se midieron utilizando un calibrador digital con una precisión de 0,01 mm. Se determinaron parámetros lineales incluyendo ancho anteroposterior del cuerpo vertebral (14,03 mm), ancho transversal del cuerpo vertebral (24,45 mm); altura del cuerpo vertebral (10,64 mm); longitud del pedículo (R: 5.65 ± 1,91 mm, L: 5.65 ± 1,76 mm); ancho del pedículo (R: 3,72 mm, L: 3,61 mm); altura de la lámina (R: 9,87 mm, L: 9,86 mm); longitud transversal de la lámina (R: 13,41 mm, L: 13,49 mm); Diámetro anteroposterior del proceso articular superior (R: 7,26 mm, L: 7,46 mm); Diámetro transversal del proceso articular superior (R: 9,87 mm, L: 9,58 mm); Altura articular superior del proceso (R: 16,41 mm, L: 16,08 mm); Diámetro anteroposterior del proceso articular inferior (R: 7,67 mm, L: 7,44 mm); Diámetro transversal del proceso articular inferior (R: 10,32 mm, L: 10,09 mm); Altura del proceso articular inferior (R: 12,72 mm, L: 12,67 mm); longitud del proceso espinoso (17,91 mm); ancho del proceso uncinado (R: 4,37 mm, L: 3,78 mm); altura de proceso uncinado (R: 4,58 mm, L: 3,93 mm); longitud del proceso uncinado (R: 9,28 mm, L: 9,12 mm); Ancho anteroposterior del foramen vertebral (13,85 mm); Diámetro transverso del foramen vertebral (20,88 mm); Ancho anteroposterior del foramen transverso (R: 4,23 mm, L: 4,28 mm); Diámetro transverso del foramen transverso (R: 4,78 mm, L: 4,95 mm). Además, la distancia del vértice del proceso uncinado al foramen transverso (R: 2,91 mm, L: 2,70 mm) y la distancia del vértice del proceso uncinado al foramen intervertebral (R: 5,77 mm, L: 5,66 mm) Se encontraron diferencias significativas entre los dos lados, en el ancho y la altura del proceso uncinado, y la distancia entre el proceso uncinado y el foramen transverso. Las mediciones actuales sugieren que los parámetros relevantes de las vértebras cervicales se pueden usar como referencia y punto de referencia anatómicos para evaluar los cambios patológicos y minimizar las complicaciones en la columna cervical.

The foramen transversarium of typical and atypical cervical vertebrae: morphology and morphometry / El foramen transverso de vértebras cervicales típicas y atípicas: morfología y morfometría

The seven cervical vertebrae found in the human body are classified into typical and atypical vertebrae. Their transverse processes contain foramen transversarium (FT) and traditionally there is one foramen present on each side, of similar size. However, variations of this foramen regarding its shape, size, number, laterality, location and osteometric characteristics have been documented in the literature. This morphological and morphometric study was conducted on 126 cervical vertebrae (82 typical and 44 atypical) obtained from the osteological bank at the University of Kwa-Zulu Natal to produce a database which may serve as a useful guideline to medical personnel. There were variations observed regarding shape, number of FT, laterality and position, which have not previously been reported. The most types of variations were evident in the typical cervical vertebrae, then secondly, the seventh cervical vertebrae. The axis vertebrae did not display any accessory FT or variations.

Las siete vértebras cervicales que se encuentran en el cuerpo humano se clasifican como vértebras típicas y atípicas. Sus procesos transversos presentan un foramen transverso (FT) y normalmente este foramen es de tamaño similar en cada lado. Sin embargo, se han reportado en la literatura variaciones de este foramen, con respecto a su forma, tamaño, número, lateralidad, ubicación y características osteométricas. Este estudio morfológico y morfométrico se realizó en 126 vértebras cervicales (82 típicas y 44 atípicas) obtenidas del banco de Osteología de la Universidad de Kwa-Zulu Natal, para producir una base de datos que pueda servir como una guía útil para el personal médico. Se observaron variaciones con respecto a la forma, el número de FT, la lateralidad y la posición, que no se habían reportado anteriormente. La mayoría de los tipos de variaciones eran evidentes en las vértebras cervicales típicas y en segundo lugar en las séptimas vértebras cervicales. Los axis no mostraron ningún FT accesorio o variaciones.

Anatomical variations of the foramen transversarium in cervical vertebrae / Variaciones anatómicas del foramen transverso en vértebras cervicales

The cervical vertebrae are recognized mainly by the presence of the foramen transversarium, which is crossed by the vertebral artery and vein, accompanied by sympathetic fibers. The main objective of this study was to observe and describe the anatomy and variations in the foramen transversarium. 121 cervical vertebrae were analyzed, including the macroscopic characteristics, shape and diameter and presence of the foramen transversarium, as well as the accessory foramen transversarium. All cervical vertebrae presented the foramen transversarium, with a mean diameter of 5.60 mm and a mean diameter of 4.40 mm on the right and 5.92 mm - 5.56 mm on the left, respectively. With regard to shape classification according to Taitz et al. (1978), 90.08 % presented the same shape on both sides, and 9.91 % had different shapes. The presentation of the different shapes was as follows: shape 1 41.32 %; shape 2 4.13 %; shape 3 18.8 %; shape 4 14.04 %; and shape 5 12.39 %. Regarding the presence of accessory foramen transversarium, 17.35 % of the vertebrae presented it, 66.6 % unilateral, 57.14 % on the right side and 42.85 % on the left side. Osteophytes, were presented in 5.7 %. The anatomical knowledge of these variations is useful for spine surgeons in preoperative planning and for preventing vertebral vessel and sympathetic nerve injuries during cervical surgical approaches.

Las vértebras cervicales son reconocidas principalmente por la presencia del foramen transverso (FT), por el cual transita la arteria y vena vertebral además de fibras simpáticas. Las variaciones en el FT pueden estar asociadas con una alteración en el calibre y el curso de la arteria vertebral. El objetivo del presente estudio fue observar y describir la anatomía así como las variaciones en el FT. Fueron analizadas 121 vértebras cervicales, en las cuales el FT fue observado macroscópicamente de manera bilateral así como el foramen transverso accesorio (FTA) en las que se encontrara presente. La forma y diámetros máximo y mínimo del FT fue medido de manera bilateral con ayuda de un cáliper digital. De 121 vértebras cervicales, la totalidad presentaron FT con diámetros máximo y mínimo derecho de 5,60 y 4,40 mm respectivamente y de 5,92 y 5,56 mm máximo y mínimo del lado izquierdo. Con respecto a la clasificación de forma de Taitz et al. (1978) el 90,08 % presentó la misma forma de manera bilateral y un 9,91% formas distintas. La forma 1 se presentó en un 41,32 %, la 2 en un 4,13 %, forma 3 18,8 %, 4 14,04 % y 5 en 12,39 %. Con respecto a la presencia de FTA, un 17,35 % lo presentó, siendo 66,6 % unilaterales, un 57,14 % derecho y 42,85 % izquierdo. La anatomía y variaciones en el FT y la arteria vertebral y los componentes nerviosos están interrelacionados. Su conocimiento morfológico es clínicamente importante, ya que el curso de la arteria vertebral puede distorsionarse en tales situaciones. Por lo que es importante a la hora de adoptar medidas cautelares para salvaguardar la arteria vertebral en las cirugías de columna cervical.

Anterior Transposition of Anomalous Tortuous Vertebral Artery Causing Cervical Radiculopathy: A Report of 2 Cases and Review of Literature.

OBJECTIVE: Cervical radiculopathy secondary to compression from vertebral artery (VA) tortuosity is a rare entity. We describe successful transposition through an anterolateral approach of tortuous VA loops causing cervical radiculopathy. METHODS: Two patients with cervical radiculopathy (first case at C5-6 and second case at C3-4) secondary to anomalous VA loop compression underwent anterolateral approaches to the cervical spine for decompression and VA transposition. The anterior transverse foramina were drilled to unroof the VA loop, which was dissected free from the exiting nerve root. RESULTS: In both cases, the affected cervical nerve root was successfully decompressed with both radiographic and clinical improvements in radiculopathy symptoms. We found 8 other cases of VA transposition via either an anterolateral approach or a posterolateral approach described in the literature. Our second case of anterolateral VA transposition at the C3-4 level is the first case at this level and the highest level reported in the literature. CONCLUSIONS: Decompression using an anterolateral approach with direct microvascular transposition of the VA is a safe and effective treatment of this pathology and addresses the cause of radiculopathy more directly than the posterolateral approach.

Atlas occipitalisation associated with other anomalies in a 16th century skeleton from Sardinia (Italy).

Archaeological excavations carried out in the plague cemetery of 16th century Alghero (Sardinia) brought to light the skeleton of a male aged 35-45 years, showing anomalies of the atlas. A macroscopic and radiological study has been carried out. The first cervical vertebra is fused with the skull base, resulting in an occipitalisation of the atlas. Absence of the costal element of the left foramen transversarium, resulting in an open anterior foramen transversarium, and posterior arch defect are also observed. The atlanto-occipital junction is a complex structure, susceptible to develop different patterns of congenital defects. These anatomical variations of atlas should be considered in modern clinical practice in order to formulate a correct diagnosis and to conceive an appropriate treatment. Osteoarchaeological cases are important as, beside to ascertain the presence of congenital defects in past populations, allow an in-depth study in dry bones, which can help modern medicine in interpreting anatomical variations. We present an association of congenital anomalies of the atlanto-occipital junction, a condition rarely documented in ancient and modern human skeletal remains.

Anatomical variations of the foramen transversarium in cervical vertebrae: findings, review of the literature, and clinical significance during cervical spine surgery.

PURPOSE: To describe certain anatomical variations of the foramen transversarium, in spine cervical vertebrae in a contemporary specimen of an Indo-European population and approach their clinical importance during cervical spine surgery. METHODS: 102 cervical vertebrae (C2-C7) from 17 different skeletons, intact without any degenerative or traumatic disorders, which belonged to the collection of the Department of Anatomy, were examined. The age of specimens at the time of their death was between 25 and 65 years. All foramina were measured with a digital caliper. RESULTS: The average size of the normal foramina was: 6.49 mm × 5.74 mm on the right side and 6.65 mm × 5.76 mm on the left side. Regarding the variations, we found two cervical vertebrae (1.96 %), one C3 and one C6, in which the right foramen transversarium is clearly smaller than the left. The exact dimensions of these foramina are: 2.3 mm × 2.5 mm on the right side and 6.54 mm × 8 mm on the left side in the first vertebra and 2.8 mm × 3.74 mm on the right side and 6 mm × 7.5 mm on the left side, in the second one. We also observed double foramina in 14 vertebrae (13.72 %). In seven vertebrae, the duplication was bilateral (6.86 %). We finally found one vertebra (0.98 %) with triplication of the foramen transversarium on the left side. CONCLUSIONS: Summarizing, 10 out of our 17 skeletons were presented with variations (extremely narrow or multiple foramina). This finding of hypoplastic, duplicated and triplicated foramina transversaria in unexpectedly high rates raises questions about the integrity of the contained structures, the possibility of a different path for them. These variations may induce an extra-osseous position of the vertebra artery, and the ignorance of such an event may have catastrophic consequences during a surgery in the cervical spine.

Short communication: Traits unique to genus Homo within primates at the cervical spine (C2-C7).

From a comparative study of 222 human and 261 nonhuman primates complete cervical spines, two bony variants associated to the course of the vertebral artery are proposed as unique to genus Homo within primates. First, the opening of the foramen transversarium at C2, a trait present at low frequency in humans (3 to 5.6%). Second, the presence of a bipartite foramen transversarium in the cervical segment C3-C6, a trait that can be observed fully formed in human fetal skeletons, with a clear frequency pattern along the cervical spine (C3>C4>C5>C6