OBJECTIVE: To explore the anatomical parameters of the cervical uncinate process "inflection point" through cervical CT angiography (CTA) and MRI measurements, offering a reliable and safe anatomical landmark for anterior cervical decompression surgery. METHODS: A retrospective analysis was conducted on the cervical CTA and MRI imaging data of normal adults who met the selection criteria between January 2020 and January 2024. The CTA dataset included 326 cases, with 200 males and 126 females, aged 22-55 years (mean, 46.7 years). The MRI dataset included 300 cases, with 200 males and 100 females, aged 18-55 years (mean, 43.7 years). Based on the CTA data, three-dimensional models of C ₃-C ₇ were constructed, and the following measurements were obtained from the superior view: uncinate process "inflection point" to vertebral artery distance (UIVD), uncinate process tip to vertebral artery distance (UTVD), uncinate process "inflection point" to "inflection point" distance (UID), uncinate process long-axis to sagittal angle (ULSA), and uncinate process "inflection point" to transverse foramen-sagittal angle (UITSA). From the anterior view, the anterior uncinate process to sagittal angle (AUSA) was measured. From the posterior view, the posterior uncinate process to sagittal angle (PUSA) was measured. Based on the MRI data, uncinate process "inflection point" to dural sac distance (UIDD) and dural sac width (DSW) were measured. The trends in measurement parameters of C ₃-C ₇ were observed, and the differences in measurement parameters between genders and between the left and right sides of the same segment were compared, as well as the difference in UID and DSW within the same segment was compared. RESULTS: The measurement parameters from C ₃ to C ₇ in the CTA data showed a general increasing trend, with no significant difference between the left and right sides within the same segment ( P>0.05). The UIVD, UTVD, and UID were greater in males than in females, with significant differences observed in the UIVD and UTVD at C ₃ and C ₆ and UID at C ₃, C ₆, and C ₇ ( P<0.05). The MRI measured DSW showed a general increasing trend from C ₃ to C ₇, and the DSW at C ₆ was greater in females than in males, with a significant difference ( P<0.05). The UIDD showed a gradual decreasing trend, with the smallest value at C ₆. There was no significant difference between males and females or between the left and right sides within the same segment ( P>0.05). The UID was greater than the DSW at C ₃-C ₇, and the differences were significant ( P<0.05). CONCLUSION The uncinate process "inflection point" is a constant anatomical structure located at the anteromedial aspect of the uncinate process tip and laterally to the dural sac. It maintains a certain safe distance from the vertebral artery. As a decompression landmark in anterior cervical spine surgery, it not only ensures surgical safety but also guarantees complete decompression.
Humans ; Adult ; Male ; Female ; Middle Aged ; Retrospective Studies ; Cervical Vertebrae/surgery* ; Magnetic Resonance Imaging ; Decompression, Surgical/methods* ; Young Adult ; Adolescent ; Computed Tomography Angiography ; Imaging, Three-Dimensional ; Vertebral Artery/anatomy & histology* ; Anatomic Landmarks/diagnostic imaging*

OBJECTIVETo construct a human cervical spine with bilateral vertebral artery fluid-solid coupling model.

METHODSHelical CT images under the principle of reverse engineering and meshed in finite element model（FEM） related software were used to establish a human cervical spine with bilateral vertebral artery fluid-solid coupling model. In the process of modeling of vertebral body, vertebral artery, ligament, intervertebral disc, cartilage and endplate large anatomic data and cadaver experiments results were referenced. From the morphology and function the simulation of model with real physiological status was tested.

RESULTSThe study showed that the stress concentration on the surface of vertebral body and the blood wall of the bilateral vertebral artery, and the result of the volume flow rate-time curve of bilateral vertebral artery of the model were consistent with the published literatures. This model was well consistent with the clinical phenomenon.

CONCLUSIONThe three-dimensional FEM of the human cervical spine established by the introduced method has been effectively verified. The modeling method would provide a new tool for research on the cervical spine biomechanics.

Biomechanical Phenomena ; Cadaver ; Cervical Vertebrae ; anatomy & histology ; Finite Element Analysis ; Humans ; Intervertebral Disc ; Models, Anatomic ; Tomography, Spiral Computed ; Vertebral Artery ; anatomy & histology

OBJECTIVETo investigate the relationship of upper cervical pedicle and vertebral artery (VA) location in order to improve the safety of transpedicular screw insertion.

METHODSThe vertebral arteries on 12 sides of 6 adult pate cadaverous specimens were dissected. The distance between VA and VA groove at the atlas needling point of transpedicle screw, and the distance between VA and the inner edge of axis cervical foramen, and the VA external diameter in axis cervical foramen were measured respectively.

RESULTSThe distance between VA and VA groove was (1.96 ± 0.72) mm on the left and (1.99 ± 0.61)mm on the right at the atlas needling point of transpedicle screw, the distance between VA and the inner edge of axis cervical foramen was (2.23 ± 0.43) mm on the left and (2.30 ± 0.39) mm on the right, the VA external diameter in axis cervical foramen was (3.03 ± 0.48) mm on the left and (2.98 ± 0.75) mm on the right.

CONCLUSIONIt is unlikely to injury VA when the transpedicle screws of upper cervical vertebrae were implanted correctly besides high straddled VA, and the individualization must be performed in the process.

Adult ; Aged ; Cervical Vertebrae ; surgery ; Female ; Fracture Fixation, Internal ; methods ; Humans ; Male ; Middle Aged ; Pedicle Screws ; Vertebral Artery ; anatomy & histology

OBJECTIVETo study clinical significance of vertebral artery magnetic resonance angiography (MRA) to vertebral artery type of cervical spondylosis' diagnosis and treatment.

METHODSThere were two groups in the study, which were observation group and control group. There were 53 patients in observation group,including 19 males and 34 females,with a mean age of (52.51 +/- 11.29) years. There were 30 subjects in control group,including 10 males and 20 females,with a mean age of (48.11 +/- 12.21) years. Based on the vertebral artery MRA picture,the course and caliber of vertebral artery were compared between two groups.

RESULTSThe abnormal incidence of course and caliber of vertebral artery in observation group was higher than that of control group, which had statistic difference (P=0.000). Furthermore, the patterns of abnormal course and caliber of vertebral artery in observation group were complicated and diverse, but the regional circuity and stegnosis was the most common pattern,about 47.18%(25/53). The cause of circuity and stegnosis was vertebra Gu-Cuofeng,about 43.41% (23/53).

CONCLUSIONThe vertebral artery MRA provides a guidance for the diagnosis of abnormal course and caliber of vertebral artery in vertebral artery cervical spondylosis.

Adult ; Aged ; Cervical Vertebrae ; blood supply ; Female ; Humans ; Magnetic Resonance Angiography ; methods ; Male ; Middle Aged ; Radiography ; Spondylosis ; diagnosis ; diagnostic imaging ; therapy ; Vertebral Artery ; anatomy & histology ; diagnostic imaging

The aortic arch gives rise to three classical branches, namely the brachiocephalic trunk, the left common carotid artery and the left subclavian artery. We report a rare variation of the left common carotid artery and the right vertebral arteries originating from the brachiocephalic trunk, and the left vertebral artery that was arising from the arch of the aorta, proximal to the origin of the left subclavian artery. Variations in the branching pattern of the arch of aorta can alter the cerebral haemodynamics that leads to cerebral abnormalities. Knowledge of the variations in the classical branches of the arch of aorta is important in the diagnosis of intracranial aneurysm after subarachnoid haemorrhage.
Aorta, Thoracic ; abnormalities ; pathology ; Brachiocephalic Trunk ; abnormalities ; anatomy & histology ; Cadaver ; Carotid Artery, Common ; abnormalities ; anatomy & histology ; Humans ; Male ; Middle Aged ; Subclavian Artery ; abnormalities ; anatomy & histology ; Vertebral Artery ; abnormalities ; anatomy & histology

OBJECTIVETo study the microsurgical anatomy of the posterior inferior cerebellar artery (PICA) for neurosurgery.

METHODSTwenty Chinese adult brain samples (40 sides) were measured with microscope for the diameters, lengths, origins, courses, and the branches of the PICA. The relationship between the PICA and cranial nerves was also checked.

RESULTSThere were 35 PICAs in 20 brain samples. The mean diameter of the PICAs was (1.6 +/- 0.6) mm, the mean length from PICAs' origin of vertebral artery to the vertebrobasilar junction was (16 +/- 5) mm. In 35 PICAs, 28 PICAs go through the rootlets of XII cranial nerves, 7 PICAs go through inferior XII cranial nerves, and 32 PICAs go through the rootlets of XI cranial nerves.

CONCLUSIONSPICA is an important branch artery with more variation and complex relationship to the cranial nerves trend in the vertebral artery system. It is necessary to master the microsurgical anatomy of PICA and to be careful protection during the neurosurgical operations.

Adult ; Carotid Artery, Common ; anatomy & histology ; Cerebellum ; blood supply ; Cerebral Arteries ; anatomy & histology ; Cranial Nerves ; anatomy & histology ; Humans ; Vertebral Artery ; anatomy & histology

OBJECTIVETo study relevant anatomical features of the structures involved in transoral atlanto-axial reduction plate (TARP) internal fixation through transoral approach for treating irreducible atlanto-axial dislocation and providing anatomical basis for the clinical application of TARP.

METHODSTen fresh craniocervical specimens were microsurgically dissected layer by layer through transoral approach. The stratification of the posterior pharyngeal wall, the course of the vertebral artery, anatomical relationships of the adjacent structures of the atlas and axis, and the closely relevant anatomical parameters for TARP internal fixation were measured.

RESULTSThe posterior pharyngeal wall consisted of two layers and two interspaces: the mucosa, prevertebral fascia, retropharyngeal space, and prevertebral space. The range from the anterior edge of the foramen magnum to C(3) could be exposed by this approach. The thickness of the posterior pharyngeal wall was (3.6+/-0.3) mm (ranging 2.9-4.3 mm) at the anterior tubercle of C1, (6.1+/-0.4) mm (ranging 5.2-7.1 mm) at the lateral mass of C(1) and (5.5+/-0.4) mm (ranging 4.3-6.5 mm) at the central part of C(2), respectively. The distance from the incisor tooth to the anterior tubercle of C(1), C(1) screw entry point, and C(2)screw entry point was (82.5+/-7.8) mm (ranging 71.4-96.2 mm), (90.1+/-3.8) mm (ranging 82.2-96.3 mm), and (89.0+/-4.1) mm (ranging 81.3-95.3 mm), respectively. The distance between the vertebral artery at the atlas and the midline was (25.2+/- 2.3) mm (ranging 20.4-29.7 mm) and that between the vertebral artery at the axis and the midline was (18.4+/- 2.6) mm (ranging 13.1-23.0 mm). The allowed width of the atlas and axis for exposure was (39.4+/-2.2) mm (ranging 36.2-42.7 mm) and (39.0+/-2.1) mm (ranging 35.8-42.3 mm), respectively. The distance (a) between the two atlas screw insertion points (center of anterior aspect of C(1) lateral mass) was (31.4+/-3.3) mm (ranging 25.4-36.6 mm). The vertical distance (b) between the line connecting the two C(1) screw entry points and that connecting the two C(2) screw entry points (at the central part of the vertebrae, namely 3-4 mm lateral to the midline of C(2) vertebrae) was (21.3+/-2.7) mm (ranging 19.4-24.3 mm), with an a/b ratio of 1.3-1.5. The screws of TARP had a lateral tilt of 12.2 degrees+/-0.4 degrees(ranging 10.2 degrees-14.6 degrees) at C(1) and a medial tilt of 7.3 degrees+/-0.3 degrees (ranging 5.1 degrees-9.4 degrees) at C(2) relative to the coronal plane.

CONCLUSIONSAn atlanto-axial surgery through transoral approach is safe and feasible. This approach is suitable for an anterior TARP internal fixation, and the design of the internal fixation system should be based on the above anatomical data.

Atlanto-Axial Joint ; anatomy & histology ; surgery ; Bone Plates ; Bone Screws ; Cadaver ; Decompression, Surgical ; methods ; Humans ; Internal Fixators ; Joint Dislocations ; surgery ; Mouth ; surgery ; Spinal Fusion ; methods ; Vertebral Artery ; anatomy & histology

OBJECTIVETo explore the arterial origin of the facial nerve and the site of the arteries joining it in cerebellopontine angle (CPA), in order to provide anatomical data for clinical application.

METHODSThe nutrient arteries were observed on 22 fresh adult head specimens fixed and perfused with formalin and gelatin under operation microscope.

RESULTSOf all the nutrient arteries of facial nerve motor root,31 were derived from the artery loops in CPA space (50.82%) and 17 from the branch of anterior inferior cerebellar artery (27.88%). Eight of them originated from the labyrinthine artery (13.1%), 3 from posterior inferior cerebellar artery (4.92%) and 2 from basilar artery (3.28%) respectively. Forty-seven nutrient arteries (77.05%) entered the proximal 1/3 segment of facial nerve motor root. Thirty-six nutrient arteries of nervus intermedius raised from the artery loops in CPA space (73.47%), 7 from the branch of anterior inferior cerebellar artery (14.29%) and 6 from labyrinthine artery (12.24%) respectively.

CONCLUSIONSThe observation of the arterial origin of the facial nerve and the site of the arteries joining it in cerebellopontine angle provided an anatomic basis for the etiology of hemifacial spasm and the microsurgical operation in CPA.

Adult ; Brachial Artery ; anatomy & histology ; Carotid Artery, Internal ; anatomy & histology ; Cerebellopontine Angle ; anatomy & histology ; blood supply ; Facial Nerve ; anatomy & histology ; blood supply ; Female ; Humans ; Male ; Microscopy, Electron ; Vertebral Artery ; anatomy & histology

OBJECTIVETo determine the location of the vertebral artery foramens from C(3) to C(6) and their relationship to the point 1 mm medial to the center of the lateral mass and to identify the value of oblique radiograph for cervical lateral mass screw trajectory by a cadaveric study.

METHODS(1) Twenty-eight cervical specimens (C(3)-C(7)) of human cadavers aged from 28 to 79 years were analysed. The transverse radiographs of C(3)-C(6) vertebrae were taken and the angle between the parasagittal plane and the line connecting the point of the lateral mass with the lateral limit of the transverse process foramen of C(3)-C(6) were measured. (2) The K-wires were drilled into lateral mass of C(3)-C(6) starting 1 mm medial to the center of the lateral mass and exiting by the juncture between the transverse process and the facet in ten specimens. Four wire placements under direct visualization, including placement of the wire tip staying the ventral cortex and 2, 4, 6 mm over-penetration of the ventral cortex of lateral mass, were performed separately on each specimen. After each placement, radiographs were taken on 45 degrees oblique left and 45 degrees oblique right views. Each intervertebral foramen on the oblique radiographs was divided into two parts: superior and inferior parts. The former is the true intervertebral foramen, while the latter is the intertransverse foramen on the gross specimen. The number of wire tips in each part was quantified for each placement. All results on the radiographs were compared with those on the gross anatomy.

RESULTS(1) The angles between the parasagittal plane and the line connecting the posterior starting point of the lateral mass with the lateral limit of the transverse foramen (C(3)-C(6)) were lateral to the sagittal plane, ranging from 5 degrees to 12 degrees. Among the vertebrae, there were no statistically significant difference (P > 0.05). (2) 15% of the wires without over-penetration and 41.3% with 2 mm over-penetration were found in the inferior parts of the intervertebral foramen in oblique views, while the wires were not noted in the intervertebral foramen by gross anatomy. with 4 mm over-penetration of the ventral cortex, 35% and 65% of wires were noted in the superior and inferior parts of the intervertebral foramen respectively, while only 28.8% of wires were found in the inferior part approximating the nerve roots in gross specimens. With 6 mm over-penetration, the number in the intervertebral foramen were 63.8% superiorly and 36.2% inferiorly on the oblique radiographs while all the tips were at the inferior part (intertransverse foramens) in gross specimens. The tip of wire crossed the line connecting the posterior borders of the intervertebral foramens in oblique radiographs when it penetrated the ventral cortex of lateral mass 4 mm or more.

CONCLUSIONS(1) There is no risk of damaging the vertebral artery if a screw is directed more than 15 degrees lateral to the sagittal plane at C(3 approximately 6) starting 1 mm medial to the center of the lateral mass. (2) Ideal screw tip position on oblique radiograph may not cross the line connecting the posterior borders of the intervertebral foramen on radiograph. If the screw tip is noted in the superior part of intervertebral foramen on the oblique radiograph, the screw may be identified as dangerous.

Adult ; Aged ; Bone Screws ; Cadaver ; Cervical Vertebrae ; anatomy & histology ; surgery ; Humans ; Internal Fixators ; Middle Aged ; Models, Anatomic ; Spinal Fusion ; instrumentation ; methods ; Spinal Nerve Roots ; anatomy & histology ; Vertebral Artery ; anatomy & histology

OBJECTIVESTo study the shape and the structures in the craniocervical junction region (CCJR) and the safety of far lateral approach.

METHODSTen cadaveric heads and 20 skull-base specimens were fixed with 10% formalin, and 4 of the 10 cadaveric heads were sectioned in different plane with the aid of operative microscope. The shape and relation of structures in the CCJR were observed.

RESULTSThe third segment of the vertebral artery(VA) was 21.6(15.3 31.9) mm. An incomplete bony canal was found to be 15% and complete bony canal surrounding the VA to be 5% on the VA groove. The distance of the left and right VA was 14.3a(c)(9.8 15.2) mm on the entry into the dura. The length of the occipital condyle was 26.8(25.1 28.2) mm, with the thickness of its anterior, middle and posterior one-third part was 9.9(9.6 10.6) mm, 11.2(9.2 13.1) mm and 8.6 (8.3 9.0) mm respectively. The distance between the posterior pole of the occipital condyle and the intracranial orifice of the hypoglossal canal was 9.9(8.6 11.4) mm, and between the posterior pole and the extracranial orifice was 16.1(13.5 17.1) mm. The transverse process of the atlas was the most important bony landmark for the approach.

CONCLUSIONSKnowing the shape and relationship of the VA and occipital condyle in the CCJR is helpful in preserving the important structures in far lateral approach to target region.

Humans ; Microsurgery ; Occipital Bone ; anatomy & histology ; Skull ; anatomy & histology ; surgery ; Vertebral Artery ; anatomy & histology