INTRODUCTION: ADVANCES IN BIOTECHNOLOGY
With the recent advances in biotechnology, spinal decompression has evolved into a cost-effective nonsurgical treatment for herniated and degenerative spinal disc disease, one of the major causes of back pain. This nonsurgical treatment for herniated and degenerative spinal disc disease works on the affected spinal segment by significantly reducing intradiscal pressures.
Chronic low back pain disability is the most expensive benign condition that is medically treated in industrial countries. It is also the number one cause of disability in persons under age 45. After 45, it is the third leading cause of disability.
Disc disease costs the health care system more than $50 billion a year.
The intervertebral disc is made up of sheets of fibers that form a fibrocartilaginous structure, which encapsulates the inner mucopolysaccharide gel nucleus. The outer wall and gel act hydrodynamically. The intrinsic pressure of the fluid within the semirigid enclosed outer wall allows hydrodynamic activity, making the intervertebral disc a mechanical structure.
As a person utilizes various normal ranges of motion, spinal discs deform as a result of pressure changes within the disc.4 The disc deforms, causing nuclear migration and elongation of annular fibers. Osteophytes develop along the junction of vertebral bodies and discs, causing a disease known as spondylosis. This disc narrows from the alteration of the nucleus pulposus, which changes from a gelatinous consistency to a more fibrous nature as the aging process continues. The disc space thins with sclerosis of the cartilaginous end plates and new bone formation around the periphery of the contiguous vertebral surfaces. The altered mechanics place stress on the posterior diarthrodial joints, causing them to lose their normal nuclear fulcrum for movement. With the loss of disc space, the plane of articulation of the facet surface is no longer congruous. This stress results in degenerative arthritis of the articular surfaces.
This is especially important in occupational repetitive injuries, which make up a majority of work-related injuries. When disc degeneration occurs, the layers of the annulus can separate in places and form circumferential tears. Several of these circumferential tears may unite and result in a radial tear where the material may herniate to produce disc herniation or prolapse. Even though a disc herniation may not occur, the annulus produces weakening, circumferential bulging, and loss of intervertebral disc height. As a result, discograms at this stage usually reveal reduced interdiscal pressure.
The early changes that have been identified in the nucleus pulposus and annulus fibrosis are probably biomechanical and relate to aging. Any additional trauma on these changes can speed up the process of degeneration. When there is a discogenic injury, physical displacement occurs, as well as tissue edema and muscle spasm, which increase the intradiscal pressures and restrict fluid migration.6 Additionally, compression injuries causing an endplate fracture can predispose the disc to degeneration in the future.
The alteration of normal kinetics is the most prevalent cause of lower back pain and disc disruption and thus it is vital to maintain homeostasis in and around the spinal disc; Yong-Hing and Kirkaldy-Willis7 have correlated this degeneration to clinical symptoms. The three clinical stages of spinal degeneration include:
- Stage of Dysfunction. There is little pathology and symptoms are subtle or absent. The diagnosis of Lumbalgia and rotatory strain are commonly used.
- Stage of Instability. Abnormal movement of the motion segment of instability exists and the patient complains of moderate symptoms with objective findings. Conservative care is used and sometimes surgery is indicated.
- Stage of Stabilization. The third phase where there are severe degenerative changes of the disc and facets reduce motion with likely stenosis.
Spinal decompression has been shown to decompress the disc space, and in the clinical picture of low back pain is distinguishable from conventional spinal traction.8,9 According to the literature, traditional traction has proven to be less effective and biomechanically inadequate to produce optimal therapeutic results.8-11 In fact, one study by Mangion et al concluded that any benefit derived from continuous traction devices was due to enforced immobilization rather than actual traction.10 In another study, Weber compared patients treated with traction to a control group that had simulated traction and demonstrated no significant differences.11 Research confirms that traditional traction does not produce spinal decompression. Instead, decompression, that is, unloading due to distraction and positioning of the intervertebral discs and facet joints of the lumbar spine, has been proven an effective treatment for herniated and degenerative disc disease, by producing and sustaining negative intradiscal pressure in the disc space. In agreement with Nachemon’s findings and Yong-Hing and Kirkaldy-Willis,1 spinal decompression treatment for low back pain intervenes in the natural history of spinal degeneration.7,12 Matthews13 used epidurography to study patients thought to have lumbar disc protrusion. With applied forces of 120 pounds x 20 minutes, he was able to demonstrate that the contrast material was drawn into the disc spaces by osmotic changes. Goldfish14 speculates that the degenerated disc may benefit by lowering intradiscal pressure, affecting the nutritional state of the nucleus pulposus. Ramos and Martin8 showed by precisely directed distraction forces, intradiscal pressure could dramatically drop into a negative range. A study by Onel et al15 reported the positive effects of distraction on the disc with contour changes by computed tomography imaging. High intradiscal pressures associated with both herniated and degenerated discs interfere with the restoration of homeostasis and repair of injured tissue.
Biotechnological advances have fostered the design of Food and Drug Administration-approved ergonomic devices that decompress the intervertebral discs. The biomechanics of these decompression/reduction machines work by decompression at the specific disc level that is diagnosed from finding on a comprehensive physical examination and the appropriate diagnostic imaging studies. The angle of decompression to the affected level causes a negative pressure intradiscally that creates an osmotic pressure gradient for nutrients, water, and blood to flow into the degenerated and/or herniated disc thereby allowing the phases of healing to take place.
This clinical outcomes study, which was performed to evaluate the effect of spinal decompression on symptoms of patients with herniated and degenerative disc disease, showed that 188 of the 219 patients who completed therapy reported immediate resolution of symptoms, and 84% of those remained pain-free 90 days post-treatment. Physical examination findings revealed improvement in 92% of the 219 patients who completed the therapy.