A to Z Entries
Clare E. Milner in 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 *
Alexander R. Vaccaro, Charles G. Fisher, Jefferson R. Wilson in 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
Michael Y. Wang, Andrea L. Strayer, Odette A. Harris, Cathy M. Rosenberg, Praveen V. Mummaneni in Handbook of Neurosurgery, Neurology, and Spinal Medicine for Nurses and Advanced Practice Health Professionals, 2017
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 case of advanced ankylosing spondylitis complicated with cervical myelopathy due to ossification of yellow ligament in which bone histomorphometry demonstrated delayed calcification
Published in Modern Rheumatology Case Reports, 2020
Naoki Kondo, Tatsuki Mizouchi, Kai Kubota, Naoto Endo
His physical status included multiple enthesopathy and pain, especially in bilateral insertions of the Achilles tendon. The result of a Shorber test was 0 cm, and he also demonstrated bilateral hip flexion contracture. Plain X-ray imaging revealed marked ankylosis in his sacroiliac joints (Figure 1(a)) and Computed tomography also showed complete ankylosis in his sacroiliac joint (Figure 1(b)). In the lumbar spine, ankylosis so-called “bamboo spine” and syndesmophyte was detected (Figure 1(c,d)). In the thoracic spine, ankylosis and a syndesmophyte were detected and kyphosis of the spine was observed (Figure 1(e,f)). In the cervical spine, ossification of anterior longitudinal ligament and cross-linking between vertebral columns were observed. Lateral x-ray revealed enthesopathy in the insertions of both Achilles tendons and plantar fascia (Figure 2).
The role of the facet capsular ligament in providing spinal stability
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2018
Emily A. Bermel, Victor H. Barocas, Arin M. Ellingson
Previous reports have suggested the importance of FCL in flexion (Adams and Hutton 1983), however our data show extension ROM and stiffness was the most impacted by FCL removal (Figure 3). The quality of motion was also altered, as seen by the translation of the helical axes anteriorly and inferiorly (Figure 4a). The facet joint space maps show that the constrained the surfaces during extension; when the FCL was removed, the surfaces slipped past each other (Figure 4c), directly impacting the axis of rotation. These results indicate that the FCL is extremely important for managing spinal extension – clinically thought to be the sole role of the anterior longitudinal ligament. This role is consistent with the horizontal alignment of the collagen fibers in the FCL and their load-bearing properties (Little and Khalsa 2005). Removal of the FCL did not alter motion much in flexion, likely because the interspinous, intertransverse, and supraspinous ligaments compensated for the altered mechanics. In general removal of the FCL would distribute the loads to other structures in the model. Flexion did not have a large difference in motion with the removal of the FCL so it is likely that there would be no change in load distribution. During extension, the anterior longitudinal ligament and the intervertebral disc would have been recruited.
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
Chaochao Zhou, Ryan Willing
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.
Related Knowledge Centers
- Kyphosis
- Vertebra
- Ligament
- Vertebral Column
- Intervertebral Disc
- Sacrum
- Basilar Part of Occipital Bone
- Atlas
- Anterior Sacrococcygeal Ligament
- Anterior Atlantooccipital Membrane