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Medical Articles »Mark Shelub, M.D.
Vertebral Axial Decompression: A Noninvasive Treatment Method for Low Back Pain
Mark Shelub, M.D.
Orthopedic Medicine / Physical Medicine and Rehabilitation
While we would like to alleviate low back conditions through the most cost-effective and noninvasive means, some low back pain sufferers, especially those with degenerative disc disease, don't improve despite our best efforts at conservative care. Some of these patients undergo successively more invasive procedures the more refractory their spine conditions are to medical care. They may undergo multiple injections, disc heating procedures, surgery and even repeat surgeries. Various and complex methods of pain control may be attempted if they still do not improve. These medical services are costly and often patients are left considerably dysfunctional and disabled.
Lumbar traction applied by the physical therapist may be used in an effort at decompression, but results are variable. Some patients may have more pain because of traction induced muscle spasm. There are reports in the medical literature of another method of applying traction, Vertebral Axial Decompression or VAX-D. This method of applying a noninvasive decompressive distraction force to the lumbar spine intervertebral disc and nerve root is reported to help those with disc disease before having to resort to medically or surgically invasive procedures. This article is being provided to educate and demystify this treatment technique.
What is the VAX-D Table?
Vertebral Axial Decompression is achieved by means of the VAX-D table. The VAX-D therapeutic table was invented by Dr. Allen Dyer, former Deputy Minister of Health in Ontario, Canada. The patient lies prone with the upper body over the stationary part of the table. The patient is stabilized by holding onto adjustable hand grips. The patient may let go of these hand grips at any time for safety. The table is a split table design, whereby distraction tensions are applied to the patient through a pelvic harness attached to a tension meter and by separation of the moveable part of the table. The distraction relaxation cycles are automated or variably timed. Distraction tensions and rates are continuously monitored and measured by the tension meter with the output shown on a digital gauge and captured on a pen-write printout. The table is reported to work by decompressing the intervertebral disc without eliciting reflex paravertebral muscle contraction.
What is Disc Decompression?
Disc decompression means decreased pressure inside the disc. During normal daily activities, intradiscal pressure may vary from 25 to 280 mm Hg depending on posture. Ramos and Martin measured intradiscal pressure by connecting an intradiscally placed cannula to a pressure transducer (1). Intradiscal pressures were recorded at resting state and while controlled tension was applied to the lumbar spine by the VAX-D table via the pelvic harness. Increasing tension was observed to decompress the disc (nucleus pulposus) to below -150 mm Hg.
No other traction device has been shown to similarly decrease intradiscal pressure. Many traction devices actually increase intradiscal pressure, most probably by inducing reflex muscle spasm. VAX-D decreases intradiscal pressure to a negative value (conventional traction has never been shown to significantly decrease and may actually increase intradiscal pressure). Treatment results have shown than sixty to seventy percent of patients improve significantly with VAX-D (no such success rate has been demonstrated with conventional traction).
Why Do We Want Disc Decompression?
What is the significance of disc decompression, and why is it desirable? Because the disc is an avascular structure and receives nourishment through diffusion, compressive or sheering forces on the disc may diminish oxygen supply, making the disc more susceptible to injury. In lowering intradiscal pressure to a negative range, a diffusion gradient favorable to the disc is allowed. With decompression, there is enhanced blood flow to the disc. Oxygen and solute exchange are facilitated; healing and regeneration are supported.
Additionally, with significant reduction of intradiscal pressure, a suction force is brought to bear on the disc herniation. The suction force promotes retraction of the disc herniation towards the center of the disc. With retraction of the disc herniation, the nerve root may be decompressed as well. Tilaro demonstrated that in patients with disc related radiculopathy and abnormal sensory function Current Perception Threshold (CPT) neurometer parameters significantly improve with VAX-D therapy (2). Disc decompression and possibly disc herniation retraction achieved with VAX-D therapy appear to allow for nerve root decompression and a return to normal sensory function as measured by normalization of CPT readings.
Also of importance is the role inflammation plays in disc herniation and nerve root compression. Phospholipase A2, arachidonic acid and other chemicals mediate the inflammatory response to injury. However, oral anti-inflammatory medicines are frequently ineffective for disc disease symptomatology. VAX-D therapy, in facilitating oxygen and solute exchange by promoting a diffusion gradient favorable to the disc, may allow for a higher concentration of anti-inflammatory medicine within the disc itself. This may help suppress disc and nerve root inflammation responsible for disabling low back and leg pain.
Do Patients’ Symptoms Improve With Non-Surgical Disc Decompression?
An abstract of a 1998 study, "Vertebral axial decompression therapy for pain associated with herniated or degenerative discs or facet syndrome; An outcome study," reads as follows:
"The outcomes of vertebral axial decompression (VAX-D) therapy for patients with low back pain from various causes are reported. Data was collected from twenty-two medical centers for patients who received VAX-D therapy for low back pain, which was sometimes accompanied by referred leg pain. Only patients who received at lease ten sessions and had a diagnosis of herniated disc, degenerative disc, or facet syndrome, which was confirmed by diagnostic imaging, were included in this study; a total of 778 cases. The average time between the initial onset of symptoms and the beginning of therapy was 40 months, and it was four months or more in 83% of the cases. The data contained the patient's quantitative assessments of there own pain, mobility, and ability to carry out the usual 'activities of daily living.' The treatment was successful in 71% of the 778 cases, when success was defined as a reduction in pain to 0 or 1, on a 0 to 5 scale. Improvements in mobility and activities of daily living correlated strongly with pain reduction" (3).
The Costs and the Results
The following information is taken by permission from: "A Direct Approach to Resolving Work-Related Musculoskeletal Disorders of the Lumbar Spine" (4).
"The Average cost of VAX-D treatment is approximately $3,000.00. An average course of daily VAX-D therapy lasts four weeks. The average VAX-D patient receives full disability payments for less than four weeks. After treatment, seventy-five percent of VAX-D patients will have a subjective pain rating of less than 2 (scale 0-5 = no pain). Sixty-five percent or more of VAX-D patients return to their previous work within six weeks.
In comparison, invasive procedures may be quite costly. Taking into account surgical, hospital, and post-procedure medication costs and physical therapy fees, invasive procedures may range in cost from $12,000.00 for Intradiscal Electrothermal Annuloplasty (IDET) upwards to $75,000.00 for complex spine surgery cases.
For every dollar spent in medical costs associated with lumbar spine injuries, there are many additional dollars spent in disability payments. The average disability cost associated with a lumbar spine surgery is $33,000.00. The average cost of lumbar spine surgery including disability ranges from $60,000.00 to $95,000.00. The average cost of VAX-D treatment including disability payments is $8,000.00."
What Happens After Years of Treatment?
Perhaps the high cost of invasive treatment could be justified were patients to improve significantly for the long term with such care, but the following is a comparison of lumbar spine surgery versus VAX-D four years after treatment.
Surgery versus VAX-D
Sixty-nine percent still complain of back pain, 73% decrease in the average pain level compared to pre-VAX-D treatment, 33% of this group complain of constant, heavy pain, 52% gained complete remission of symptoms with no further treatment, 46% had residual sciatica, 80% returned to work, 5% were still under some kind of treatment, 67% returned to same job, 3% of patients were receiving disability payments, 17% underwent repeat surgery.
Who is a Candidate for VAX-D Therapy?
Patients with herniated or degenerative disc disease, with or without radiculopathy, who have not responded to usual conservative care, are candidates for VAX-D therapy.
Patients with complex or extensive lumbar spine degenerative bone or disc disease may be candidates also. Obviously, VAX-D treatment will not alter the degeneration itself, but if the patient's low back and / or leg pain is caused by a compressed nerve root or other lesion responsive to decompression, VAX-D treatment can be very helpful. For instance, pain from degenerative lateral recess stenotic nerve root compression can be greatly relieved. VAX-D therapy can decompress the nerve root within the lateral recess stenotic canal. I have treated numerous elderly patients with radiologically demonstrated extensive lumbar spine degenerative disease and their low back and leg pain are frequently eliminated with VAX-D treatment.
Patients presenting with post-surgical failed back syndrome may be candidates as well, so long as bony integrity is not significantly compromised. Generally speaking, however, surgically altered lumbar spines are more difficult to treat. In my experience, the more extensive the surgery, the less effective VAX-D becomes. However, should the post-surgical patient's pain be caused by compression of pressure sensitive tissue above or below the level of surgery, for example, VAX-D treatment can be extremely helpful. The presence of surgical hardware in the spine would contraindicate VAX-D treatment.
Other contraindications to VAX-D therapy would include fracture, unstable spondylolisthesis, infection, and cauda equina syndrome.
The Last Question
This last question may be the most difficult to answer. If VAX-D therapy is so successful, why are relatively few lumbar spine patients being treated with VAX-D?
Cost is not an answer, VAX-D therapy is indicated for herniated and degenerative disc disease unresponsive to first line usual conservative care. In these cases, where more complex or invasive care is indicated, the cost of VAX-D therapy compared to the surgical alternative is fractional.
One answer may be that VAX-D treatment is still viewed as experimental or investigational. The VAX-D table, however, has two marketing clearances from the FDA. In the FDA Summary of Safety and Effectiveness, the "indication for and intended use" of the VAX-D table is described as follows:
"The VAX-D table is designed to relieve pressure on structures that may be causing low back pain. It relieves the pain associated with herniated discs, degenerative disc disease, posterior facet syndrome, and radicular pain. It achieves these effects through decompression of intervertebral discs, that is, unloading due to distraction."
When the VAX-D procedure is ordered by a physician operating within the scope of his or her specialty to treat or diagnose an eligible medical condition, found appropriate by the FDA, as is the case with VAX-D for patients presenting with incapacitating low back pain, VAX-D therapy cannot be regarded as "experimental or investigational." Perhaps the real answer to our last question has to do with how we view lumbar spine disease and treatment. Most patients I see for VAX-D therapy consultation have disabling low back pain resistant to conservative care. Following failure of conservative care, most are told to live with their pain or have surgery. The "surgical" concept of lumbar spine disease and treatment, so dominant in the thinking of physicians and patients alike, compels us to look at disc herniation, resistant to physical therapy, as something to be removed, not healed. Non-surgical decompression of the degenerated or herniated disc leading to regeneration and healing is a seemingly simple but still unbelievable concept. After all, how can daily VAX-D treatment over a period of several weeks solve the essentially "surgical" problem of disc herniation?
This is the question many patients before beginning VAX-D treatment. Interestingly, a few ask the same question even after positively responding to treatment, not believing it was the VAX-D therapy that healed them, and some of these patients had low back pain and disability for months or even years prior to undergoing their successful several week course of VAX-D treatment. Physicians and patients alike may need to reevaluate the current prevalent surgical model of lumbar spine disease and care.
The fact is non-surgical decompression of the lumbar spine resolves the pain and disability of lumbar spine herniated or degenerative disc disease in most patients treated. This means that most lumbar spine herniated or degenerative disc disease will positively respond to non-surgical decompression. Our current predominantly surgical model of care for lumbar spine herniated disc disease resistant to physical therapy is incomplete without recognition of this fact.
In certain instances, invasive procedures are needed, but we all must become aware that for patients having failed their initial trail of conservative care, there remains a very effective alternative to invasive procedures or having to living with chronic pain. Non-surgical decompression through VAX-D therapy should be seriously considered in all cases of lumbar spine herniated and degenerative disc disease before proceeding with invasive procedures.
References
(1) Ramos G., Martin W. "Effects of Vertebral Axial Decompression on Intradiscal Pressure," J. Neurosurgy 1994; 81: 350-353.
(2) Tilaro F., Miskovich D. "An overview of Vertebral Axial Decompression," Canadian Journal of Clinical Medicine, January 1998.
(3) Gose, Naguszewski and Naguszewski "Vertebral Axial Decompression therapy for pain associated with herniated or degenerative discs or facet syndrome; An outcome study," Neurological research 1998; 20: 186-1900.
(4) Wayne Clark and Associates, LLC, "A Direct Approach to Resolving Work-Related Musculoskeletal Disorders of the Lumbar Spine" 1999.
(5) Tilaro F., Miskovich D, Effects of Vertebral Axial Decompression on Sensory Never Dysfunction, Canadian Journal of Clinical Medicine
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