The mechanical response of intervertebral joints is deeply influenced by disc degeneration. The phenomenon is expressed in terms of variations in the biomechanical properties of the material, whose compressibility characteristics change because of the liquid content loss in the tissue and, what is even more important, to prolapse. In this work, the problem is investigated by means of a computational mechanics approach; a coupled material and geometric non-linear model is developed, representing vertebra, annulus and nucleus submitted to an axial load. A transversely isotropic law is assumed for cortical bone in the vertebral body and an isotropic law for the cancellous portion; a hyperelastic formulation is assumed for the disc, allowing effective interpretation of the mechanical characteristics of degeneration. The results obtained are reported with regard to bony endplate and annulus behaviour; interaction phenomena between bony endplate and nucleus are emphasized.
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http://dx.doi.org/10.1016/0141-5425(93)90120-n | DOI Listing |
Vet Radiol Ultrasound
September 2024
Division of Diagnostic Imaging, Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht, The Netherlands.
Spine J
September 2024
Department of Orthopedics, Luzhou Key Laboratory of Orthopedic Disorders, The Affiliated Traditional Chinese Medicine Hospital, Southwest Medical University, Luzhou 646000, Sichuan Province, PR China. Electronic address:
Background Context: Adjacent vertebral fracture (AVF) is a frequently observed complication after percutaneous vertebroplasty in patients with osteoporotic vertebral compressive fracture (OVCF). Studies have demonstrated that intervertebral cement leakage (ICL) can increase the incidence of AVF, but others have reached opposite conclusions. The stress concentration initially increases the risk of AVF, and dispersive concentrated stress is the main biomechanical function of the intervertebral disc (IVD).
View Article and Find Full Text PDFBiofabrication
October 2024
School of Pharmacy, College of Medicine, National Cheng Kung University, No.1, University Road, Tainan 701, Taiwan (R.O.C).
Interbody fusion is an orthopedic surgical procedure to connect two adjacent vertebrae in patients suffering from spinal disc disease. The combination of synthetic bone grafts with protein-based drugs is an intriguing approach to stimulate interbody bone growth, specifically in patients exhibiting restricted bone progression. Recombinant human thrombomodulin (rhTM), a novel protein drug characterized by its superior stability and potency, shows promise in enhancing bone formation.
View Article and Find Full Text PDFSensors (Basel)
September 2024
Department of Radiology, VA San Diego Healthcare System, San Diego, CA 92161, USA.
Introduction: The disco-vertebral junction (DVJ) of the lumbar spine contains thin structures with short T2 values, including the cartilaginous endplate (CEP) sandwiched between the bony vertebral endplate (VEP) and the nucleus pulposus (NP). We previously demonstrated that ultrashort-echo-time (UTE) MRI, compared to conventional MRI, is able to depict the tissues at the DVJ with improved contrast. In this study, we sought to further optimize UTE MRI by characterizing the contrast-to-noise ratio (CNR) of these tissues when either single echo or echo subtraction images are used and with varying echo times (TEs).
View Article and Find Full Text PDFInterv Pain Med
June 2024
OSS Health, York, PA, USA.
Background: True lateral imaging (TLI), obtained by superimposing bilateral lumbar spine structures and aligning superior endplate cortical bone, requires deliberate rotational adjustments of the laterally positioned fluoroscope in both the axial and longitudinal planes. True lateral segmental imaging is necessary to depict true and accurate radiofrequency (RF) cannula positioning relative to bony anatomy during lumbar medial branch radiofrequency neurotomy (LMBRFN).
Objective: To determine the interobserver reliability of TLI during LMBRFN.
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