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Published in Clare E. Milner, Functional Anatomy for Sport and Exercise, 2019
The lumbar spine is the distal end of the mobile portion of the vertebral column. The vertebral bodies are large and strong and the articular facets are oriented obliquely to prevent intervertebral rotation movements. The lumbar spine has a large flexion-extension range of motion and is supported by the common longitudinally running ligaments of the vertebral column (see thoracic region – ligaments). The strong and wide anterior longitudinal ligament runs the length of the vertebral column and is attached to the anterior surface of the vertebral bodies and intervertebral discs; it helps to prevent hyperextension of the vertebral column. The thinner and weaker posterior longitudinal ligament is attached to the posterior surface of the intervertebral discs and lies inside the vertebral canal. The posterior wall of the vertebral canal is formed by the ligamentum flavum, which connects adjacent vertebral arches at the laminae. The remaining ligaments connect the various processes of the vertebrae. The interspinous ligaments lie between adjacent spinous processes and weakly connect them. The strong supraspinous ligament connects the tips of the spinous processes and helps to prevent hyperflexion. There are also thin and weak intertransverse ligaments in the lumbar region which connect adjacent transverse processes.
The Treatment of Certain Cervical-Spine Disorders by Anterior Removal of the Intervertebral Disc and Interbody Fusion *
Published in Alexander R. Vaccaro, Charles G. Fisher, Jefferson R. Wilson, 50 Landmark Papers, 2018
At this point, the authors were able to identify the anterior longitudinal ligament (ALL). After placing a spinal needle in the suspected disc space, a lateral radiograph was obtained to confirm the intervertebral level. Through a small flap in the ALL, the authors removed the intervertebral-disc material and adjacent cartilage endplates using pituitary rongeurs and curettes. Large anterior osteophytes were partially removed to allow access to the disc space, but an effort was made to preserve the superior and inferior cortical bone edges, enabling the bone graft to be posteriorly countersunk. In this series, the exposed intervertebral space accepted a block of bone 10 to 15 mm high, 10 to 15 mm wide, and 10 to 15 mm deep.
Neuroanatomy overview
Published in Michael Y. Wang, Andrea L. Strayer, Odette A. Harris, Cathy M. Rosenberg, Praveen V. Mummaneni, Handbook of Neurosurgery, Neurology, and Spinal Medicine for Nurses and Advanced Practice Health Professionals, 2017
Carolina Sandoval-Garcia, Daniel K. Resnick
The main ligaments include anterior and posterior longitudinal ligaments, which span the entire length of the spinal column as well as others with varying functions related to their moment arm, namely, interspinous, supraspinous, intertransverse, flavum, and capsular. The anterior longitudinal ligament begins in the occiput and travels down to the sacrum in longitudinally arranged fibers covering up to a third of the anterior surface of each vertebral body. The ligament is thickest over the vertebral bodies, and the more posterior layer actually binds the edges of the intervertebral discs. Of note, the ligament portion from occiput to C1 is also referred to as anterior atlantooccipital membrane.
A finite element analysis of different pedicle screw placement strategies for treatment of Lenke 1 adolescent idiopathic scoliosis: which is better?
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Kai Chen, Jian Zhao, Yunfei Zhao, Changwei Yang, Ming Li
Although this study found interval and alternate screws instrumentation could be an optimal strategy for AIS surgery, there were some limitations to be addressed. Firstly, owing to the design of our study, anterior longitudinal ligament, posterior longitudinal ligament, ligamentum flavum, interspinous ligament were ignored in our model, the influences of these ligaments were not evaluated while analyzing the stresses. Secondly, the results of this study are based on a single Lenke 1 patient with mild scoliosis. Thirdly, in order to simplify the model, we have just performed rod rotation procedures to correct the curve, other correction techniques such as distraction, compression and apex vertebrae derotation techniques were not included in the analysis process. Besides, the stresses were observed as high as 3000 MPa in our study which may cause screw materials failure theoretically. However, there was no evidence how much stress should internal fixation bear during the process of deformity correction. And it is impractical to measure the stress of screws or rod directly during operation. Therefore, the absolute value of stress was ignored in this study for that the current study aimed to assess the correction rate and stress difference between groups, which may need improvement in the future study. Therefore, the results should be further explored in a more comprehensive test.
The relationship of diffuse idiopathic skeletal hyperostosis, visceral fat accumulation, and other age-related diseases with the prevalent vertebral fractures in elderly men with castration-naïve prostate cancer
Published in The Aging Male, 2020
Daisuke Watanabe, Hiromitsu Takano, Takahiro Kimura, Akemi Yamashita, Tadaaki Minowa, Akio Mizushima
Diffuse idiopathic skeletal hyperostosis (DISH) is a disease in which the longitudinal ligaments and tendon attachments of the spinal cord gradually become ossified, causing ankylosing disorders of the spine [9]. Although ossification of the anterior longitudinal ligament is the main characteristic, it is sometimes accompanied by ossification of the posterior longitudinal ligament, the yellow ligament, and the extraspinal ligament. When multiple vertebral bodies are connected by ossification, the spine loses motility, causing falls due to imbalance and immobilization-associated osteoporosis [10]. The risk of vertebral fracture in patients with DISH is known to be higher than that in patients without DISH [10]. Although the cause of DISH is unknown, it is more common in males than in females, and it has been reported that aging, obesity, and type 2 diabetes are associated with the increase of its prevalence [11–15]. It is reported that the prevalence of DISH in males is 13–22.7% [12,15,16], while that in male patients over 70 years of age is 38–44% [17]. Most patients with prostate cancer are elderly males. Moreover, visceral fat obesity is attracting attention as a risk factor because of the relationship between the progress of prostate cancer and visceral fat accumulation [18,19]. With these partially common epidemiological characteristics of prostate cancer and DISH, patients with prostate cancer are expected to have a high prevalence of DISH.
Sensitivities of lumbar segmental kinematics and functional tissue loads in sagittal bending to design parameters of a ball-in-socket total disc arthroplasty prosthesis
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Although a single ball-in-socket TDA design was focused in this study, we have demonstrated that segment kinematics and intersegment tissue load-sharing at the treated level (L3–4) were markedly changed by the implantation of the TDA prosthesis, depending on different design parameters, but only slight changes in the responses of adjacent segments (L2–3 and L4–5) were predicted. Furthermore, a tradeoff relationship between these two performance metrics of segmental kinematics and intersegment tissue load-sharing may exist; the tradeoff needs to be further validated by examining the design space more rigorously or systematically. Regardless, these findings highlight that TDA design optimization considering both metrics simultaneously is necessary, in order to mitigate relevant TDA postoperative complications and lower the risk of secondary surgical interventions. Since the anterior surgical approach which dissects anterior spinal structures deteriorates the resistance to sagittal bending at the TDA-treated level, future FE studies could further examine the sensitivity of TDA biomechanics to anterior longitudinal ligament status; correspondingly, new mechanisms in TDA design which compensates for the structural defect are also desired to restore normal segment biomechanics.