e

Be Wary of Spinal Decompression Therapy
with VAX-D or Similar Devices

Stephen Barrett, M.D.

The VAX-D® Therapeutic Table is a motorized traction device used to stretch the lower back. (VAX-D is an acronym for vertebral axial decompression.) The device is a two-part table in which the upper part is fixed to the table frame and the lower part slides back and forth to provide intermittent traction. The patient is anchored to the lower part by a pelvic harness. United States patents have been issued for the table [1], the harness [2], and the table's operation [3]. The picture to the right shows the VAX-D control unit and table.  

VAX-D therapy is usually provided in an outpatient setting for the purpose of relieving back pain. Its providers—chiropractors, medical and osteopathic physicians, and physical therapists—commonly recommend 20 sessions of 30-45 minutes, with a total cost of several thousand dollars. During the treatment, the patient lies face-down with the upper part of the body on the stationary portion of the table, with arms overhead, grasping handles attached to the this part of the table. A pneumatic cylinder drives the two parts of the table apart and together to provide gradual stretching alternating with relaxation. A typical cycle includes a minute of each [4]. The patient can limit the amount of traction by releasing the handles if too much discomfort occurs.

The structures of the back include the spinal bones (vertebrae), their joints, the discs between the vertebrae, and the muscles and ligaments that hold these structures together. The intervertebral discs, which serve as cushions between the vertebrae, are composed of cartilage with a gelatinous-like center called the nucleus pulposus. Discs can become damaged so that they bulge or tear. If a tear is large enough, the gelatinous material can leak out, a condition referred to as a herniated or "ruptured" disc, which can press against a spinal nerve and cause pain and loss of nerve function. Ordinary traction in which a steady stretching force is applied to the pelvis using weights and pulleys has not been proven effective against back pain [5,6]. VAX-D's intermittent traction can be effective for pain associated with bulging discs. However, manual manipulation, which costs far less, is equally effective. No type of traction has proven effective for herniated discs [7], which often require surgery. Although the VAX-D Therapeutic Table has FDA approval as a traction device, it is illegal to claim that it can correct a herniated disc.

Since this article was originally published, several similar devices—Decompression Reduction Stabilization (DRS) System, Accu-Spina System, DRX-3000, DRX9000, SpineMED Decompression Table, Antalgic-Trak, and Lordex Traction Unit, and a less elaborate device called the Triton DTS—have entered the marketplace. New devices typically cost from $80,000 to $125,000. Used used ones typically cost between $20,000 and $40,000. Although this article focuses on the VAX-D, the same considerations apply to all of them.

Regulatory History

The Federal Food, Drug, and Cosmetic Act requires that all medical devices be safe and effective for their intended purposes and that manufacturers bear the burden of proof. The Act divides devices into three classes based on the principle that the greater the potential hazard, the more rigorous the regulatory requirements and the higher the class. Class I devices, such as bandages, tongue depressors, and others whose failure is unlikely to cause serious harm, usually do not require permission to market. However, to market a new Class II or Class III device, a manufacturer usually must go through an approval process. Devices that are "substantially equivalent" to others already approved require much less substantiation than would be required for those that are entirely new. Section 510(k) of the act requires manufacturers—90 days before starting distribution in interstate commerce—to inform the FDA how they believe the device should be classified and what steps they have taken to comply with the rules for substantiation. The notice that is filed is commonly referred to as a "510K notification" or simply a "510K."

The VAX-D table and procedures were developed by Allan E Dyer, Ph.D., M.D., [8].who had served as Deputy Minister of Health in Ontario, Canada, from September 11, 1985, to October 5, 1987. Correspondence obtained from the FDA files suggests that Dyer obtained FDA approval for one purpose but later attempted to market it for another. On August 3, 1989, the VAX-T Pelvic Traction Belt secured 510K clearance to enter the United States marketplace after its manufacturer (VAT-TECH, Inc., of Ontario. Canada) notified the FDA that it was "substantially equivalent" to a pelvic traction device that had been marketed in interstate commerce for many years [8]. In 1991, Dyer amended this 510K to change the name to VAX-D [9].

In 1994, FDA district offices in Newark and Orlando began receiving calls from consumers asking whether the device was FDA-approved and whether claims made for it were valid [10]. As a result, early in 1995, Dyer was asked to clarify how the VAX-D was similar to the VAX-T and whether it has the same intended uses [11]. Dyer responded that "the VAX-D is the same device as previously identified as VAX-T in function and design," but he also claimed that the device could decompress the intervertebral discs as measured by a lowering of intradiscal pressures [12]. However, in May 1995, an FDA official concluded that the VAX-D was significantly different and that the "decompression" claim was a "new intended use" that required premarket approval and a new 510K application [13].

During the next few months, Dyer and a consultant attempted to explain that use of the word "decompression in VAT-TECH's literature was "an attempt to explain the mechanism of action" [14] and that other wording to which the FDA had objected were simply "meant to clarify or modernize terminology consistent with current medical practice." [15] In December 1995, the FDA notified Dyer that the new 510K application was deficient and that various claims would have to be either substantiated or stopped [16]. The key points were:

VAT-TECH's responses described no information that the FDA considered sufficient to substantiate the claims that the FDA questioned. After some discussion, Dyer agreed to comply with all of the FDA's demands [17], initiated a recall of all previously distributed manuals [18], and warned its providers not to state that research had demonstrated that VAX-D caused "decompression." [19] VAT-TECH also notified its providers that its headquarters had been relocated (from Canada) to Palm Harbor, Florida [19]. The 510K application was approved on July 2, 1996. The company is now doing business as Vax-D Medical Technologies. The VAX-D table costs about $125,000 [20]. Several other companies have had similar devices approved.

Scientific Status

Proponents claim that VAX-D treatment can relieve low back pain by decompressing discs, improving the flow of nutrients into the disc, rehydrate dried-out discs, and thereby help restore the disc structure. Some of these claims are based on a 1994 study by Gustavo Ramos, M.D., and William Martin, M.D., who concluded that VAX-D can lower pressure inside the intervertebral discs [21]. The study involved five patients with protruding lumbar discs, but only the data for three patients were reported. The pressure within these discs was measured by inserting tiny tubes (cannulas) connected to a measuring device. The researchers reported that various levels of traction with the VAX-D device caused the intradiscal pressure to become lower. However, Alf Nachemson, M.D., Ph.D., the Swedish orthopedist who pioneered studies of intradiscal pressure severely criticized the experimental setup [22]. In the early 1980s, Nachemson and two colleagues found that during active traction, intradiscal pressure actually rises when the back muscles contract to resist the traction [23]. Equally important, it has not been demonstrated that intermittent lowering of intradiscal pressure can restore the structure or function of the disk. For these reasons, the FDA ordered VAT-TECH not to make any such claim [16]. Furthermore, even if VAX-D therapy can lower intradiscal therapy and reduce disk bulging while the patient is on the table, it has not been proven that such changes persist after the patient resumes standing.

Proponents also claim that a large study published in 1998 found that VAX-D was 71% effective in reducing pain in patients with herniated discs, degenerated discs, facet syndrome, and sciatica. This claim is based on data on 778 patients who had had at least 10 VAX-D treatments at one of 22 "medical centers." [24] However, the study was so poorly designed that no conclusions about effectiveness can be drawn from the published report:

The Washington Department of Labor and Industries has published two technology assessments of powered traction devices used for intervertebral decompression. Both reports concluded that published literature had not demonstrated that such devices are more effective than other forms of traction, other conservative treatments, or surgery [25,26]. In 2005, the WorkSafeBC Evidence-Based Practice Group reached a similar conclusion [27].

In 2007, a researcher at the Parker Chiropractic College Parker Research Institute noted:

There is very limited evidence in the scientific literature to support the effectiveness of non-surgical spinal decompression therapy. This intervention has never been compared to exercise, spinal manipulation, standard medical care or other less expensive conservative treatment options which have an ample body of research demonstrating efficacy. Considering the cost-benefit relationship, many better researched and less expensive treatment options are available to the clinician [28].

Also in 2007, a technology assessment done for the Agency for Healthcare Research and Quality reached similar conclusions:

Currently available evidence is too limited in quality and quantity to allow for the formulation of evidence-based conclusions regarding the efficacy of decompression therapy as a therapy for chronic back pain when compared with other non-surgical treatment options. Of the studies examined for assessment of efficacy, neither included patients over 65 years of age. Adverse event reporting for decompression therapy is infrequent. There was one case report of an enlargement of an existing disc protrusion, and other studies reported worsening of pain in some patients [29].

VAX-D treatment is promoted as being completely risk-free. However, a case of adverse effects associated with it has been reported. The patient was a 46-year-old man who had been diagnosed with a large herniated disc in the lower part of his back. During the fifth VAX-D session his pain increased abruptly and he was not able to return to work. When subsequent investigation showed that the herniation had increased, he underwent emergency surgery [30].

A study reported in 2008  involved  250  subjects who were evaluated 30 and 180 days after receiving  VAX-D treatments. Improvements in pain intensity were noted, but subject selection was based on pain intensity and activity limitation without regard to the presence or absence of spinal nerve compression. In addition, there was no control group. The authors cautioned that “causal relationships between the outcomes and the intervention cannot be made.” [31]

Questionable Marketing

Vax-D Medical Technologies' Web site contains no violative claims. However, the company's medical director, Frank Tilaro, M.D., has made forbidden claims in journal articles published in 1998 and 1999 and in a presentation to insurance industry personnel in 1999. In the 1998 article, referring to the Ramos-Martin study, he stated:

The article also stated that "Many patients who receive VAX-D therapy have had chronic back pain and failed numerous modalities including traction. Their positive response . . . confirms VAX-D's assertion that it is not conventional traction." [4] Dr. Tilaro's 1999 article reported on a study of the charts of 17 patients who had undergone VAX-D therapy at an unspecified outpatient clinic [32]. Certain sensory nerve function measurements had been made before and immediately after treatment. Although most patients had improved scores, the study has too many flaws to be considered clinically meaningful. There was no control group, which means that it is not possible to be certain whether the results were due to the treatment or to other factors (such as the passage of time). In addition: the patients were not randomly chosen; their clinical status was not reported; the people who measured and recorded the data were not blinded; and there were no follow-up scores.

An insurance investigator who attended Tilaro's 1999 presentation has told me that: (a) its purpose was to convince the attendees that VAX-D is different from traction and should be reimbursed at a higher rate using a different reimbursement code; (b) Tilaro claimed that special FDA approval distinguished VAX-D from traction; and (c) Tilaro distributed handouts [A] [B] containing claims prohibited by the FDA [33,34]. In addition, when the investigator requested further information through the company's Web site, he received a document containing violative claims [35].

During the 510K clearance procedure, the FDA warned VAT-TECH that it would be inappropriate to use testimonials for marketing purposes. Although none appear on the company's Web site, other sites display them.

The VAX-D Network offers information about the procedure, a practitioner directory; testimonials; and a message board where visitors can post comments and questions. The site states that more than 140 VAX-D units are operating throughout the United States, Puerto Rico, Canada and Australia and that more than 1,000 patients are treated each month. Several pages contain claims that the FDA told VAX-D's manufacturer not to make. The home page claims—apparently based on the 1998 report—that "low back pain sufferers with herniated discs, degenerated discs, facet syndrome and sciatica now have better than a 70% chance of resuming a normal life without the risks and complications associated with surgery." An interior page states:

The MRI picture which follows shows a severe herniated and extruded lumbar disc. A radiologist and surgeon, being unfamiliar with and having had no previous experience with VAX-D, both stated that surgery was the only solution available. However the patient, not wanting to undergo surgery, elected to be treated with VAX-D. After VAX-D, the MRI demonstrated significant improvement, the patient was pain free and returned to normal activities [36].

The testimonial page contains many brief messages in which patients describe how their pain was relieved. The descriptions do not have enough detail to analyze what happened to these people.

For several years, Universal Pain Technology Canada (UPTC), Inc. marketed the Decompression, Reduction, Stabilization System (DRS System), which it described as a "redesign" of the VAX-D Table that received FDA-approved in 1998 as a mechanical traction device. The claims made for the DRS on UPTC's Web site and in its marketing materials were identical to those made for the VAX-D. In 1999, UPTC's president, Tim Emsky, also administered the Community Back Centers Web site, which offered articles, a directory, and many anecdotes in which patients described how their pain was relieved with VAX-D therapy. Its "Question about VAX-D" page claimed that the treatment was effective for patients with herniated discs and suggested that it is an alternative to surgery. Most of these anecdotes contained insufficient detail to understand what happened, and some described problems that could not possibly have been fixed by VAX-D treatment. A Chirobase consultant who reviewed the reports believes that the patients who found relief as a result of VAX-D traction could have experienced similar relief through less-expensive treatment by hand and, in some cases, with less risk of injury.

In 2001, Emsky founded CERT Health Sciences, which markets the SpineMED Decompression. Cert's Clinic and Marketing Resources Manual includes a sample practitioner press release which states: "A remarkable result of this therapy is the promoted re-hydration of the nucelus and repair of the disc wall through nutritional transfer and fibroblast migration caused by the negative pressures created during decompression." [37] In the mid-1990s, the FDA ordered VAX-D's marketers not to make similar claims about nutrient diffusion and disc repair [16].

It is clear that individual practitioners are making violative claims. In Allentown, Pennsylvania, for example, the VAX-D procedure has been heavily advertised on the radio and in the newspaper as an alternative to surgery [38]. No well-designed study has demonstrated that VAX-D therapy can substitute for appropriately recommended surgery.

Insurance Considerations

Each year, the American Medical Association issues a list of descriptive terms and numerical codes for reporting medical services and procedures performed by physicians. The resultant database—called Current Procedural Terminology—is then incorporated into manuals published by the AMA, insurance companies, and commercial publishers. These codes are referred to as "CPT codes." Whether a service is covered depends on the contract between the insurance company and the insured person. Procedures considered unproven or experimental are not usually covered. Medicare and some insurance companies don't cover VAX-D. Aetna considers it unproven and does not cover it through its managed-care and commercial plans [39]. Some companies cover it as a form of mechanical traction, for which they pay far less than the $150 to $300 per session charged by VAX-D providers. I don't know whether how many companies pay the full charge or—if they do—whether they understand what they are paying for.

One of the handouts at Dr. Tilaro's seminar for insurance personnel stated that in 1999, Relative Value Studies, Inc., had designated a temporary code of 97532 to represent "Dynamic Vertebral Axial Decompression Progressive; through variable timed tension distraction-relaxation cycles with continuous monitoring, recording and interpretation, per session." [33] However, this code did not appear in either the 1999 or 2000 CPT manual.

In 2002, the Texas Mutual Insurance Company defeated an attempt by Daniel A. Boudreau, D.O., to collect more than $200 per session for VAX-D treatments. Twice before, when Boudreau had challenged an insurance company’s payment for VAX-D therapy, the State Office of Administrative Hearings (SOAH) had ruled in his favor. But when he billed Texas Mutual for $7,700 for VAX-D therapy for two workers’ compensation patients, the company concluded that VAX-D was a type of traction and paid $300 per patient, the maximum amount allowed for 15 sessions under the Texas Workers’ Compensation Commission Medical Fee Guideline. Boudreau appealed to SOAH and claimed that VAX-D therapy actually decompresses vertebrae, something that traction cannot do. He also asserted that because the equipment costs much more than a traction table, it should not be considered equivalent to a traction device. In rebuttal, the company produced expert testimony that the American Medical Association, FDA, and Medicare all viewed VAX-D therapy as a form of traction and that that Medicare did not cover VAX-D therapy due to insufficient scientific data to support its alleged benefits. The judge ruled that SOAH’s previous two decisions on VAX-D cases appeared to be based on incorrect information and that $20 per session was the correct payment [40].

In December 2005, the Anesthesia & Pain Coder's Pink Sheet published a devastating report about the marketing of the Vax-D, Accu-Spina, DRS, and DRX-9000. The report noted that miscoding of claims is common and that many of the payments should not have been made [41].One such code was CPT Code 64722, which is for surgical decompression of one or more nerves. Other providers have used CPT Code 97799, which is for "unlisted physical medicine/rehabilitation service or procedure." The correct code is 97012, which stands for mechanical traction.

In 2006, two chiropractors were sentenced to prison for using CPT Code 64722 to improperly collect nearly $2 million from Blue Cross and Blue Shield of Georgia. Both were sentenced to serve 34 months in a federal prison [42].

In 2007, an orthopedic surgeon and four chiropractors in Georgia were charged with carrying out similar schemes. In one case, orthopedist Howard Berkowitz, M.D. and chiropractors Arthur Hargraves and Daniel Puffenberger allegedly used CPT Code 64722 for VAX-D treatments administered at back-pain clinics that the trio owned and operated. Berkowitz, Hargraves, and Puffenberger were accused of improperly generating bills to BlueCross BlueShield of Georgia for more than $3 million for VAX-D treatments, for which they collected more than $2.4 million. In March 2007, Berkowitz pleaded guilty and agreed to pay $2,450,364 for restitution. In July 2008, a federal court jury found Hargraves and Puffenberger guilty of health care fraud. During the trial former employees testified that they had been instructed not to refer to procedures as VAX-D when dealing with insurers because insurers would not cover it [43]. In November 2008, all three were sentenced to prison, Berkowitz for 18 months and the others for 41 months.

In the other case, chiropractors William Stearns and Steven Levine allegedly used false codes to bill for more than $1.8 million for VAX-D, for which they received more than $1 million. They also billed improperly for more than $1.5 million and collected about $817,000 for use of a Hako-Med device. (Hako-Med devices are alleged to provide pain relief by administering electrical impulses to the skin.) The indictment stated that after Stearns and Levine began using VAX-D, they typically applied Hako-Med after each VAX-D treatment. In 2008, Levine pled guilty to one count of health care fraud related to VAX-D billings and Stearns was tried and convicted of 18 charges of health care fraud and five charges of money laundering.

Other Government Actions

In 1998, the FDA warned Professional Distribution Systems (PDS) that the DRS System was illegal to market because it did not have FDA clearance. PDS told an FDA inspector that it believed that a 510(k) clearance for the traction component of the system covered what the company was doing. However, the letter stated that clearance for the this component did not permit the company to make 29 claims related to intended uses that were not covered in the traction component's 510(k). [44]

In 2006, the FDA inspected the facilities of the North American Medical Corporation (which markets the Accu-Spina device) because of safety concerns that were expressed in a warning letter in 2007 [45]. However, the letter did not address the way the device is marketed.

In March 2007, Florida newspapers reported that the FBI conducted a search at Axiom Worldwide, which markets the DRX9000 and similar devices [46]. The reasons for the search are not yet public.

In July 2007, the Oregon Department of Justice announced that Axiom Worldwide, Inc. of Tampa, Florida, and Altadonna Communications, Inc. and its owner Benjamin A. Altadonna of Danville, California, had signed agreements to settle charges that the company had made deceptive claims in the marketing package it provided to buyers of the device. Axiom's package contained sample ads claiming that the DRX 9000 had an 86% success rate against degenerative disc disease, disc herniations, sciatica and post-surgical pain. The Oregon Attorney General charged that this claim could not be substantiated with competent and reliable evidence. The settlement agreement called for payment of $75,000 and prohibits Axiom from misrepresenting scientific studies and patient testimonies [47]. In 2006, Monterey County (California) prosecutors won judgments against two chiropractors who had advertised the "86% success" claim [478]. In 2007, the pair filed a class-action suit charging that they were "fraudulently induced to buy Axiom's machines based upon the fraudulent and negligent misrepresentations made by Axiom and its agents." [49]

In 2009, the Kentucky Board of Chiropractic Examiners ordered Tavis Lee Culver, D.C., to cease-and-desist making unsubstantiated statements that decompression is more effective than other forms of traction [50].

In 2009, Florida Attorney General's office accused Axiom Worldwide, its president and CEO James J. Gibson, and its vice-president Nicholas Exarhos of using false and misleading claims to market their spinal decompression machines [51]. The complaint states:

In 2011, the FDA warned Spinetronics, of Coral Springs, Florida, objected to claims that "Antalgic-Trak's posturing features provide new treatment options for arthritis, scoliosis, stenosis, spondylosis, segment subluxation, disc bulges, herniations, and pinched nerves." The warning letter said that this statement represented the device as providing treatment of these conditions rather than alleviating the pain associated with them and that some were not included in the indications for use that the FDA had cleared [52].

The Bottom Line

VAX-D is an expensive high-tech form of mechanical traction that can provide relief in some cases of back pain but is widely promoted with unsubstantiated claims that it can correct degenerated and herniated discs without surgery. When the FDA cleared the VAX-D table as a traction device, it set limits on what the manufacturer could claim. Individual providers, provider associations, and the manufacturer itself have exceeded these limits. VAX-D therapy may provide relief for properly selected patients. However, there are good reasons to believe that manual treatment can usually accomplish the same thing more quickly, safely, and less expensively. The same considerations apply to the Decompression Reduction Stabilization (DRS) System, Accu-Spina System, DRX-3000, DRX9000, SpineMED Decompression Table, and Lordex Traction Unit, which are similar devices marketed by other companies. They also apply to Triton DTS (a simpler. less expensive traction device) and the Z-Grav, a tilt table marketed through SpinalAid Centers of America, that is claimed to decompress by gravitational force.

Since 1995, I have notified FDA officials several times about improper claims made by marketers of non-surgical spinal decompression therapy. I also know that others have complained. I have seen no evidence that the FDA device officials who have the ability to stop the deceptive marketing of spinal decompression devices have any interest in doing so.

Insurance Company Clinical Policies

Additional Information

Acknowledgement

Charles Bender, D.C., of Hellertown, Pennsylvania, served as a consultant for the original version of this article.

References

  1. Pelvic harness. Patent #5,115,802, May 26, 1992.
  2. Therapeutic table. Patent #4,995,378, Feb 26, 1991
  3. Operation of a vertebral axial decompression table. Patent #6,039,737, March 21, 2000.
  4. Tilaro F. An overview of vertebral axial decompression. Canadian Journal of Clinical Medicine 5:1-7, 1998.
  5. Bigos S and others. Acute low back problems in adults: Clinical Practice Guideline #14. AHCPR Publication No. 95-0642. Rockville, MD: Agency for Health Care Policy and Research, 1994.
  6. Waddell G and others. Low Back Pain Evidence Review. London: Royal College of General Practitioners, 1996.
  7. VAX-D: No evidence from controlled trials to support claims of efficacy. The Back Letter 13(9):97,104,105, 1998.
  8. Panko R. Back pain abhors a vacuum. Best's Review, Sept 1998.
  9. Dyer AE. Letter to Robert Chissler, March 27, 1991.
  10. Riegel, EA Memo to Marie A. Schroeder, Feb 28, 1995.
  11. Riegel EA. Letter to Dr. Alan E. Dyer, Jan 11, 1995.
  12. Dyer AE. Letter to Elizabeth A. Riegel, Feb 8, 1995.
  13. Beninger P. Letter to Dr. Alan E. Dyer, April 21, 1995.
  14. Estrin N. Letter to Byron Tart, June 27, 1995.
  15. Dyer AE. Letter to FDA Office of Device Evaluation, Sept 28, 1995.
  16. Novick A. Letter to Dr. Alan E. Dyer, Dec 28, 1995. [PDF]
  17. Dyer AE. Letter to Andrew Novick, April 22, 1996.
  18. FDA Enforcement Report, Aug 14, 1996.
  19. Letter to VAX-D healthcare providers. VAX-D Letter, Volume 2, May 15, 1996.
  20. VAX-D financing: Equipment financing made easy. Vax-D Medical Technologies USA Web site. Accessed April 5, 2001.
  21. Ramos G, Martin W. Effects of vertebral axial decompression on intradiscal pressure. Journal of Neurosurgery 81:350-353, 1994.
  22. Nachemson A. Intradiscal pressure. Journal of Neurosurgery 82:1095, 1995.
  23. Andersson GB, Schultz AB, Nachemson AL. Intervertebral disc pressures during traction. Scandinavian Journal of Rehabilitation Medicine (Suppl) 9:88-91, 1983.
  24. Gose EE, Naguszewski WK, Naguszewski RK. Vertebral axial decompression therapy for pain associated with herniated or degenerated discs or facet syndrome: An outcome study. Journal of Neurological Research 20:186-190, 1998.
  25. Vertebral axial compression (Vax-D): Health technology assessment update. Washington Department of Labor and Industries, 1999.
  26. Wang G. Powered traction devices for intervertebral decompression: Health technology assessment update. Washington Department of Labor and Industries, June 14, 2004.
  27. Martin CW. Vertebral axial decompression for low back pain. Richmond, BC: WorksafeBC Evidence-Based Practice Group; 2005, Feb 2005.
  28. Daniel DM. Non-surgical spinal decompression therapy: Does the scientific literature support efficacy claims made in the advertising media? Chiropractic & Osteopathy 15:7, May 18, 2007.
  29. Tiller MJ and others. Decompression therapy for the treatment of lumbosacral pain. Agency for Health Care Research and Quality, April 26, 2007.
  30. Deen HG Jr and others. Sudden progression of lumbar disk protrusion during vertebral axial decompression traction therapy. Mayo Clinic Proceedings 78:1554-1556, 2003.
  31. Outcomes after a prone lumbar traction protocol for patients with activity-limiting low back pain: a prospective case series study. Archives of Physical Medicine and Rehabilitation 89:269-274, 2008.
  32. Tilaro F, Miskovich D. The effects of vertebral axial decompression on sensory nerve dysfunction in patients with low back pain and radiculopathy. Canadian Journal of Clinical Medicine 6(1):1-8, 1999.
  33. VAX-D treatment vs traction. Flyer distributed at VAT-Tech seminar, 1999.
  34. Comparison VAX-D vs traction. Flyer distributed at VAT-Tech seminar, 1999.
  35. VAX-D International, IBC. Flyer distributed during 1999 in response to an e-mail inquiry.
  36. About VAX-D. Vax-D Network Web site.
  37. Clinic & Marketing Resources. Baltimore: CERT Health Sciences, undated (published in either 2005 or 2006).
  38. Breakthrough for back pain. Advertisement, The Morning Call, Allentown, Pa., March 2000.
  39. Vertical Axial Decompression Therapy. Aetna Clinical Policy Bulletin Number 180, May 11, 2007.
  40. Texas Mutual wins appeal on VAX-D therapy. News release, June 11, 2002.
  41. Vogenitz W. Miscoding advice causes financial troubles, liabilities for unsuspecting anesthesia, pain offices. Anesthesia & Pain Coder's Pink Sheet, Dec 2005.
  42. Barrett S. Chiropractors convicted of miscoding VAX-D claims. Casewatch, June 16, 2006.
  43. Two chiropractors found guilty by federal jury in "VAX-D" fraud scheme. US Dept of Justice news release, July 29, 2008.
  44. Tolen DD. Warning letter to David Williams, Jan 23, 1998.
  45. Woleske, MH. Warning letter to Carlos Becerra, March 2, 2007.
  46. Watsonville chiropractor held liable for deceptive ads. Santa Cruz Sentinel, Dec 7, 2006.
  47. Zayas A. FBI agents search offices of medical equipment maker. St. Petersburg Times, March 9, 2007.
  48. AG stops out-of-state companies from using "junk science" to promote chiropractic devices: Oregon chiropractors disseminated deceptive advertisements. Oregon Department of Justice news release, June 29, 2007.
  49. Class action complaint. Tony L. Hoang, Charles C. Strong v. Axiom Worldwide et al. Alameda County Superior Court. Case No. RG07347405, filed Sept 21, 2007. (Subsequently transferred to federal court.)
  50. Logsdon L. Letter to Travis Lee Culver, Nov 6, 2009.
  51. Complaint. State of Florida vs. Axiom Worldwide et al.. Case No. 09 29033, Circuit Court of the Thirteenth Judicial District in and for Hillsborough County, Florida, filed Nov 19, 2009.
  52. Ramos E. Warning letter to David B. Bass, July 25, 2011.

This page was revised on August 18, 2011.