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Immunomodulation in Degenerated Intervertebral Disc
Published in Raquel M. Gonçalves, Mário Adolfo Barbosa, Gene and Cell Delivery for Intervertebral Disc Degeneration, 2018
Graciosa Q. Teixeira, Mário Adolfo Barbosa, Raquel M. Gonçalves
Degenerative disc disease is a chronic condition. Therefore, high and long-lasting local levels of different molecules are necessary for a continuous effect of the regenerative therapies (Vadala et al. 2015). Gene therapy has gained significant attention since it promises more prolonged effects in the treatment of IVD degeneration and mediation of inflammation and provides the possibility to locally modulate the expression of a specific gene and the consequent production of its protein (Vadala, Sowa, and Kang 2007; Vadala et al. 2015).
Test Paper 5
Published in Teck Yew Chin, Susan Cheng Shelmerdine, Akash Ganguly, Chinedum Anosike, Get Through, 2017
Teck Yew Chin, Susan Cheng Shelmerdine, Akash Ganguly, Chinedum Anosike
Causes of intervertebral disc calcification include the following: Degenerative disc disease is a relative common cause for disc calcification.Alkaptonuria, or ochronosis, results in dense central calcification affecting the nucleus pulposus and is associated with generalised osteopaenia. Changes often start at the lumbar spine.Ankylosing spondylitis is a recognised cause; associated findings helping in narrowing the diagnosis.Calcium pyrophosphate dehydrate deposition disease (CPPD), haemochromatosis and hypervitaminosis D can result in calcification of the annulus fibrosus.Transient intervertebral disc calcification is seen in children, typically in the cervical spine and spontaneously regresses.Other recognised causes of disc calcification include juvenile chronic arthritis, amyloidosis, poliomyelitis, acromegaly, hyperparathyroidism, trauma and post-operative discs.
Spine
Published in David A Lisle, Imaging for Students, 2012
Sciatica is usually caused by herniation of intervertebral disc, or by spinal stenosis due to degenerative disease. Each intervertebral disc is composed of a tough outer layer, the annulus fibrosis, and a softer semifluid centre, the nucleus pulposus. With degeneration of the disc, small microtears appear in the annulus fibrosis allowing generalized bulging of the nucleus pulposus. This causes the disc to bulge beyond the margins of the vertebral bodies causing narrowing of the spinal canal. Secondary effects of degenerative disc disease include abnormal stresses on the vertebral bodies leading to osteophyte formation, as well as facet joint sclerosis and hypertrophy. These changes may lead to further narrowing of the spinal canal producing spinal canal stenosis.
Device profile of the FlareHawk interbody fusion system, an endplate-conforming multi-planar expandable lumbar interbody fusion cage
Published in Expert Review of Medical Devices, 2023
Peter B. Derman, Rachelle Yusufbekov, Brian Braaksma
The FlareHawk Interbody Fusion System (Accelus, Palm Beach Gardens, FL) encompasses a family of lumbar interbody fusion devices, including the FlareHawk7, FlareHawk9, FlareHawk11, TiHawk7, TiHawk9, and TiHawk11 (Figure 1), along with associated instrumentation. The FlareHawk implants are multi-material, multi-planar expandable PLIF and TLIF cages that can be utilized in standard open or minimally invasive posterior lumbar fusions. Intended for use in skeletally mature patients with degenerative disc disease (DDD) at one or two contiguous levels from L2 to S1, as well as patients who have up to a Grade 1 spondylolisthesis or retrolisthesis at the surgical level(s). Each cage features a small insertion profile, designed to minimize the surgical corridor required for cage placement, while allowing substantial post-insertion expansion via a shim-in-shell design. This two-piece device consists of a PEEK outer shell that expands in width, height, and lordosis with the insertion of an inner titanium shim (Figure 2). Tantalum radiographic markers are integrated into the shell to facilitate intra- and post-operative device visualization (Figure 3). An integrated titanium ‘core’ in the shell serves as an anchor for the insertion instrumentation.
Spinal cord compression due to nucleus migration from Mobi-C total disc replacement
Published in British Journal of Neurosurgery, 2022
We report the first case of a non-traumatic posterior migration of the nucleus of a Mobi-C Cervical Disc prosthesis with significant symptomatic progressive spinal cord compression requiring aggressive surgical management. The diagnosis of the underlying pathology has not been straightforward due to the artefact in imaging. Similarly, the surgical management was very challenging since the severe adhesions of the implant to the dura required vertebrectomies in order to facilitate the removal of all implants and the adequate decompression of the spinal cord. This complication should be taken into consideration when counselling a patient about the surgical options for the management of cervical degenerative disc disease as well as during follow up of the patients that have been treated with this procedure.
Finite element study on the influence of pore size and structure on stress shielding effect of additive manufactured spinal cage
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Vijay Kumar Meena, Parveen Kalra, Ravindra Kumar Sinha
Spinal injuries and spinal disorders are becoming increasingly common ailments in modern life. One of the most common diseases/ailments is Degenerative Disc Disease, popularly known as DDD (Pannell et al. 2015). The cure involves surgical procedures of degenerated disc and insertion of appropriate implants, namely spinal cages between the vertebrae. Titanium alloy (Ti6Al4V) is the preferred choice for spinal cages due to its high tensile strength, good biocompatibility, good fatigue strength, and corrosion resistance (Ramakrishna et al. 2001). These spinal cages are generally made of solid dense metals/polymers e.g. titanium, Carbon Fiber Reinforced PEEK, etc. Young’s modulus of these materials is much higher than human bone Young’s modulus. The elastic modulus of bone varies between 1 and 20 GPa whereas the elastic modulus of titanium is 110 GPa. Due to this vast difference in elastic modulus, the loads are not transferred from the implant to adjacent bone tissue, resulting in stress shielding between the host bone and the implant. This leads to adaptive resorption of bone tissue and a decrease in mechanical rigidity of the bone as per Wolff’s law (Chen et al. 2010). Similarly, with reduced stress shielding, bone tissues are known to generate deposition of new bone, which increases mechanical rigidity (Stock 2018). Also, the smooth and shiny surface of solid metal implants makes it difficult to integrate with the host bone. This causes amyotrophy and osteonecrosis of bones around the implants, loosening of the implant, distortion of bones, etc (Haibo et al. 2012).