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Journal of Engineering and Science in... Aug 2024Advancements in automated vehicles may position the occupant in postures different from the current standard posture. It may affect human tolerance responses. The...
Advancements in automated vehicles may position the occupant in postures different from the current standard posture. It may affect human tolerance responses. The objective of this study was to determine the lateral bending tolerance of the head-cervical spine with initial head rotation posture using loads at the occipital condyles and lower neck and describe injuries. Using a custom loading device, head-cervical spine complexes from human cadavers were prepared with load cells at the ends. Lateral bending loads were applied to prerotated specimens at 1.5 m/s. At the occipital condyles, peak axial and antero-posterior and medial-lateral shear forces were: 316-954 N, 176-254 N, and 327-508 N, and coronal, sagittal, and axial moments were: 27-38 N·m, 21-38 N·m, and 9.7-19.8 N·m, respectively. At the lower neck, peak axial and shear forces were: 677-1004 N, 115-227 N, and 178-350 N, and coronal, sagittal, and axial moments were: 30-39 N·m, 7.6-21.3 N·m, and 5.7-13.4 N·m, respectively. Ipsilateral atlas lateral mass fractures occurred in four out of five specimens with varying joint diastasis and capsular ligament involvements. Acknowledging that the study used a small sample size, initial tolerances at the occipital condyles and lower neck were estimated using survival analysis. Injury patterns with posture variations are discussed.
PubMed: 38059268
DOI: 10.1115/1.4063648 -
Clinical Orthopaedics and Related... Jun 2012Craniocervical dislocations are rare, potentially devastating injuries. A diagnosis of craniocervical dislocations may be delayed as a result of their low incidence and...
BACKGROUND
Craniocervical dislocations are rare, potentially devastating injuries. A diagnosis of craniocervical dislocations may be delayed as a result of their low incidence and paucity of diagnostic criteria based on CT and MRI. Delay in diagnosis may contribute to neurological injury from secondary displacement resulting from instability. The purpose of this study was to define CT and MRI-based diagnostic criteria for craniocervical dislocations to facilitate early injury recognition and stabilization.
QUESTIONS/PURPOSES
Using CT and MRI, we (1) described the bony articular displacements characterize craniocervical injuries; (2) described the ligamentous injuries that characterize craniocervical injuries; and (3) determined whether neurologic injuries were associated with bony or ligamentous injury.
METHODS
Using a prospectively collected spinal cord injury database, we identified 18 patients with acute, traumatic occipitocervical injuries. We reviewed CT scans and MR images to document the height of the occipitoatlantal and atlantoaxial joints and integrity of craniocervical ligaments. Medical records were reviewed for neurological status. The primary measurements were number of patients with articular displacement, location of bony displacement, and number of patients with ligamentous injury.
RESULTS
Thirteen of 18 patients had displacement outside the normal range. Six patients demonstrated displacement of both occipitoatlantal and atlantoaxial joints, whereas five patients presented with displacement through the atlantoaxial joints only. Two patients had an abnormal basion-dental interval only. Of 17 patients with MR images, the cruciate ligament was injured in 11 patients, indeterminate in four, and intact in two. All five patients with occipitoatlantal articular displacement had injury to the occipitoatlantal capsule. No patient had occipitoatlantal capsular injury without occipitoatlantal articular displacement. Three cases of complete spinal cord injury were found after occipitoatlantal-atlantoaxial dislocations. Three patients with occipitoatlantal-atlantoaxial dislocations were neurologically intact. The five patients with atlantoaxial dislocations and patients without displacement or ligamentous injury were neurologically intact. Five patients had cruciate ligament rupture or indeterminate injury but no joint diastasis.
CONCLUSIONS
The occipitoatlantal joint capsules stabilize the occipitoatlantal joint; disruption of the occipitoatlantal capsule may suggest the presence of instability. Based on these findings, we identified two distinct injury patterns: isolated atlantoaxial injuries (Type I) and combined occipitoatlantal-atlantoaxial injuries (Type II). Occipitoatlantal joint capsule integrity differentiated these subsets and Type II injuries had a higher percentage of complete spinal cord injuries on presentation.
Topics: Adolescent; Adult; Aged; Atlanto-Axial Joint; Atlanto-Occipital Joint; Cervical Vertebrae; Female; Humans; Joint Dislocations; Longitudinal Ligaments; Male; Middle Aged; Tomography, X-Ray Computed; Young Adult
PubMed: 22033875
DOI: 10.1007/s11999-011-2151-0 -
Anales de Pediatria (Barcelona, Spain :... Aug 2008A female who was born after a gestation of 37 weeks without incident. A caesarean was performed due to cephalopelvic disproportion. She had no clavicles, dehiscence of...
A female who was born after a gestation of 37 weeks without incident. A caesarean was performed due to cephalopelvic disproportion. She had no clavicles, dehiscence of the sagittal suture, large anterior fontanelle and occipital prominence. A chest x-ray, abdominal and brain ultrasound and karyotype, was requested, with changes only seen in the x-ray,, which showe clavicular agenesis and flared chest. Cleidocranial dysostosis was diagnosed a family study was started. There are ten affected members in five generations. The partial or total absence of clavicles, the late closure of cranial sutures and fontanelles, the diastasis of the pubic symphysis and the flared chest during the first days of life, are constant features. Four presented characteristic facies and three delayed onset of first teeth which required extractions. There is hearing loss in three of them. The three documented childbirths were caesarean due to cephalopelvic disproportion. Other alterations are failure to thrive, coxa vara and early osteoarthritis.
Topics: Cleidocranial Dysplasia; Female; Humans; Infant, Newborn; Pedigree
PubMed: 18755123
DOI: 10.1157/13124897 -
Bulletin of Emergency and Trauma Oct 2019Sheno-occipital diastasis happens more frequently in children and is accompanied with neural and vascular injuries leading to a high rate of mortality. We present a rare...
Sheno-occipital diastasis happens more frequently in children and is accompanied with neural and vascular injuries leading to a high rate of mortality. We present a rare type of clival fracture in a 21 years old man who could survive without any deficit even though the fracture extended widely from left Asterion to the right orbit accompanied by widespread damage of the skull base air sinuses in 3D CT scan. To the best knowledge of the authors, neither this type of fracture, nor the clinical presentation, has been reported in relevant literature.
PubMed: 31858006
DOI: 10.29252/beat-070412