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Functional Rehabilitation
Published in James Crossley, Functional Exercise and Rehabilitation, 2021
The lumbar spine is composed of five vertebral segments. Each segment articulates with the segment above and below via facet joints on either side of the spine and with the intervertebral disc directly above and below, attaching to each vertebral body. In the lumbar spine, facet joints are orientated to allow flexion, extension and side-bending, but to restrict rotational movement (see Figure 7.18).
Intervertebral Disk
Published in Verna Wright, Eric L. Radin, Mechanics of Human Joints, 2020
The facet joints are the left and right articulations of the superior and inferior facets (articular processes) of adjacent vertebrae. They are synovial joints covered by hyaline cartilage. In the lumbar spine, these joints are vertically oriented and therefore restrict rotation. Because of their orientation, they are particularly important load-bearing structures in rotation and shear, but they are also loaded in compression. Farfan’s studies indicate that they contribute about 40% to the torsional resistance of a motion segment (3), which is about the same as that from the disk. Hutton et al. (4) found the load sharing to be similar when shear loads were applied, that is, disk 40% and facet joints 40%. The amount of compressive load being transmitted through the facet joints depends on whether the spine is in flexion or extension. Theoretically, more load is transmitted through the facet joints in extension. Lorenz et al. (S) found the facets to carry about 25 % of the compressive load in a neutral position.
Disc Structure and Function
Published in Peter Ghosh, The Biology of the Intervertebral Disc, 2019
The disc is not the only structure connecting the vertebrae. Figure 1 shows two vertebrae connected to form a so-called “motion segment”. The vertebral bodies or centra are connected by the anterior and posterior longitudinal ligaments, parallel to the axis of the spine, as well as by the disc.8 Further ligaments connect the vertebral arches of adjacent vertebrae, e.g., the two ligamenta flava, the interspinous ligament, and the supraspinous ligament occur in most of the lumbar region.8,9,10 Also projecting from the neural arch are the superior and inferior processes which terminate in flattened facets. The facets of adjacent vertebrae articulate (superior of one with inferior of next) in the facet joints (also known as apophyseal or zygapophyseal points). Facet joints are conventional synovial joints in which the capsular ligaments confer further stability on the spine.11–15 All of these structures assist the intervertebral disc in maintaining stability during movement of the spine16 and in its response to compression.17
Ultrasound-guided axial facet joint interventions for chronic spinal pain: A narrative review
Published in Canadian Journal of Pain, 2023
Michael J. Wong, Manikandan Rajarathinam
Facet joints are paired joints formed by the superior articular process of one vertebra and the inferior articular process of the level above.29 The articular facets of these joints are covered with hyaline cartilage and enclosed in a synovial capsule, with the total volume of each facet joint being approximately 1 mL. Facet joints provide axial stability and define the spine’s range of motion at each region. Facet joint degenerative changes may involve bony hypertrophy, loss of cartilage and synovial fluid, and associated inflammation, which may all drive spinal pain.30 However, incidental and asymptomatic facet joint degeneration is also common,31 and joint capsular disruption may also cause pain in the absence of obvious radiographic changes.32
When to consider “mixed pain”? The right questions can make a difference!
Published in Current Medical Research and Opinion, 2020
Rainer Freynhagen, Roberto Rey, Charles Argoff
In the context of low back pain, natural degeneration of facets from normal aging leads to swelling, inflammation and pain. Pain associated with a facet joint syndrome is often called “referred pain” because symptoms do not follow a specific nerve root pattern. Local tissue pathology and inflammation can cause serious painful symptoms and disability, which are hallmarks of nociceptive pain. Inflamed facets can cause a powerful muscle spasm which can become continuous, fatiguing the involved back muscles which, in turn, repeats the cycle. Bursts of movement can aggravate symptoms. Nevertheless, each joint has a rich supply of tiny nerve fibres that provide a painful stimulus when they are injured or irritated by inflammatory mediators, which can lead to a local neuropathic type of pain.
Risk factors related to adjacent segment degeneration: retrospective observational cohort study and survivorship analysis of adjacent unfused segments
Published in British Journal of Neurosurgery, 2019
Jose Ramirez-Villaescusa, Jesús López-Torres Hidalgo, Antonio Martin-Benlloch, David Ruiz-Picazo, Francisco Gomar-Sancho
Type of pedicle instrumentation, i.e. top-loading vs. side-loading screws, has been little studied as a risk factor of ASD. The facet joint contributes to segment stability and can be altered by direct injury during exposure, facet joint capsule injury and the pedicle instrumentation or as a consequence of biomechanical changes.4 Chen et al., assessed the risk of facet joint injury in relation to medial (Roy-Camille) or lateral pedicle screw-insertion technique (Weinstein) and type of instrumentation (top-loading vs. side-loading screws), and reported a higher risk of degeneration in patients intervened using medial point of entry and side-loading screws.28 A surprising finding in our study, however, was the greater number of patients with ASD who had been intervened with top-loading screws. In these patients, no association was found with other risk factors (e.g. laminectomy in patients with stenosis or a higher number of levels of fusion), and ASD must, therefore, be assumed to be related to direct facet joint injury during exposure, the medial point of entry of the screw or be a spurious association.