News / Profession

American Back Society Meets in Las Vegas: Part II

Robert Cooperstein, MA, DC

Editor's note: Part I of this article appeared in the February 22nd issue.

The Interdisciplinary Spinal Group

Complementary and alternative medicine (CAM) is an idea whose time has certainly come,1 but different models have arisen on how such care should best be administered. In a multidisciplinary setting, professionals from different disciplines each evaluate the patient independently, coming up with individual treatment plans. In an interdisciplinary setting, a case manager coordinates the services of different health professionals who communicate their findings to one another and engage in truly collaborative care. Since 1992, chiropractor William DeFoyd and his associates have been involved in a pioneering effort to implement a truly interdisciplinary system in their spine center in Austin, Texas. In previous presentations before the ABS, Dr. DeFoyd has communicated how difficult it can be, given differences in training, experience, and world views to prevent attempted interdisciplinary care from devolving into less desirable multidisciplinary care, with resulting duplication of efforts and something closer to one-stop shopping for health care than authentically collaborative care.

Organizing an interdisciplinary spine group involves clinical, financial, and operational issues. These include assembling the team, reaching consensus on patient care, continuous quality improvement and more. The key to success is the individuals themselves. They must be open minded, share a desire to learn from each other, and respect what each of the various disciplines has to offer. They must also agree to be accountable to the group. Dr. DeFoyd described the process of how the group proceeds from seed algorithms to clinical guidelines through formal consensus processes. The engine that drives the Austin group is the biweekly chart review conference, which amount to mini-grand rounds for patients who are nonimprovers.

In the end, interdisciplinary care is all about triage, matching the patient with the most appropriate care. This makes sense not only clinically, but financially. To tell the truth, to be in favor of interdisciplinary care these days is about as controversial as favoring world peace, but Dr. DeFoyd must be acknowledged as having been there when "interdisciplinary wasn't yet cool." I would also like to acknowledge the success of yet another seminal interdisciplinary back group out of Texas involving chiropractors J. Triano and D. Hansen of the Texas Back Institute.

The Neural Network

It has proven extraordinarily difficult to identify structural and kinematic correlates of back pain, even though it would seem intuitively obvious that underlying pathology should evince discernable consequences. Dr. Malcolm Pope has developed a system for collecting and analyzing large amounts of data from back patients as they go through movement patterns. The artificial neural network was able to correctly distinguish between LBP and no LBP in 321 or 380 cases solely through analyzing kinematic data.

The neural network is a processing technique that learns complex, nonlinear relationships between inputs and outputs, where the inputs are features of the patient's motion and the output is the pain classification. The nomenclature "neural network" derives from its similarity to a biological neural network, including training (learning) capacity. People with known pathology have been used to "calibrate" the classification system. Dr. Pope concludes that the classification of LBP using dynamic motion features is promising as a clinical diagnostic aid.

The SI Joint Lives!

It seemed odd, rather dated, when Dr. Donald Robertson expressed his view that "sacroiliac pain is largely unrecognized" by allopathic physicians, although "it continues to be recognized by osteopathic physicians, chiropractors, and physiotherapists." After all, there are almost annual symposia devoted to the sacroiliac joint; moreover, it has been a couple of years since I heard an orthopedic surgeon state at an ABS meeting that he couldn't budge a sacroiliac joint, no matter how hard he tried, with his hands literally on the bones. Dr. Robertson explained that historically, the SI joint had received attention prior to the Second World War, but the thought that SI joints are immovable developed almost in proportion to what has been called the "dynasty of the disk," ushered in by the seminal 1934 Mixter-Barr paper.2 As new, replacement diagnoses became in vogue, ODs and DCs kept the thought of sacroiliac pain alive.

As is often the case when an individual has a personal experience with a type of injury, Dr. Robertson learned first hand the reality of SI pain, sustaining an injury that eventually led him to orthopedic medicine. He views the SI joint as the keystone of an arch, the stability of which is increased by (a) compression and (b) the irregularity of the articular surface by the time of adulthood. Indeed, most of his patients are "youngish," since with advancing years comes SI stability. Dr. Robertson stated that fixation in an abnormal position is painful, defining this condition alternately as somatic dysfunction (a venerable osteopathic equivalent for the chiropractic S-word) and asymlocation (Dorman's made up orthopedic medicine equivalent for the S-word). In a Dynamic Chiropractic column some years ago, I wrote: "Dr. Dorman doesn't like the osteopathic term 'dysfunction,' because it seems to suggest symptoms that are often absent at some point in progressive musculoskeletal pathologies. He suggests the alternative term 'asymlocation' to represent abnormal, but possibly asymptomatic bone positions."3

According to Dr. Robertson, SI pain radiates essentially in the path of the sciatic nerve, and also in the front of the body into the inguinal area and down the side of the leg toward the trochanter. A patient may report paresthesia instead of or in addition to the pain. There are no neurologic findings. Appendectomies and ovarian resections are sometimes done in a vain attempt to eliminate SI pain. Sitting aggravates, and no position feels comfortable. Instability of the pelvic girdle gives rise to weakness, so that the knee may buckle and precipitate falling. Dorman calls this the "slipping clutch syndrome," since the function of the SI joint resembles that of a clutch, engaged on the stance leg side and disengaged on the swing leg side during locomotion, thus constituting the normal mechanical function of the joint in humans. An episodic failure of self-bracing would be due to weakened posterior SI ligaments and would account for the poorly-understood phenomena of sudden falling during walking, according to Dorman.4 Although Dr. Robertson strongly supported prolotherapy for unstable sacroiliac joints, he did not say much about treating fixated joints, nor about manipulation (although his program notes express support for the latter).

Fault Propagation and Tensegrity

Dr. Dorman discussed how and why neck and back pain often occur together, or at least said he would. Maybe I missed something, but the substance of his talk had more to do with the sacroiliac/slipping clutch metaphor, as described above, and the benefits of prolotherapy, than on how the neck and back would relate to one another. He did discuss a study he had done which investigated the contributions of the various components of walking (as measured by changes in oxygen consumption under selected biomechanical conditions), including shoulder girdle movements. Dr. Dorman introduced the concept of "fault propagation" by means of what he calls the tensegrity model. Tensegrity (a term coined by Buckminster Fuller in 1926 to refer to tension plus integrity) has to do with how the connective tissue maintains spinal stability through compression and tension, and how failure in one location can produce remote dysfunction. Dr. Dorman maintains a web page at [url=http://www.dormanpub.com]http://www.dormanpub.com[/url].

How a Doctor Can Wind Up a Poor Witness

Ms. Nancyann Leeder, Esq., who serves as a workers' compensation attorney in the state of Nevada, said she wanted to provide "an entirely different view from the earlier speakers," and that she did. As a public defender for injured workers who are being denied benefits, she has keen insight into the opposing point of view when a doctor testifies in court. She stated (approximately): "You, the doctor, devalue your position by getting away from your area of expertise and testifying on other than medical factors. The patient's history, symptoms, test results and exam finding, and your education and experience, are your areas of expertise, all of which enable you to arrive at an opinion. All this is to establish causation. On the other hand, opinions about legal matters and opinions about the worker's true motivations are another matter. You then become "fair game" by giving the impression that your medical opinion can not stand on its own."

Failure to answer the attorney's written questions is another pitfall that may result in a doctor being called to testify. Yet another, especially embarrassing, is not knowing the injured worker's job description, which invariably results in you, the doctor, getting "egg all over your face." Doctors had best focus on the questions and answer them without volunteering anything extra, or else there will be more questions. Not answering letters properly or at all will generate a subpoena, hardly well compensated at a witness fee of $25 plus travel expenses.

Thermodiscoplasty

Two presenters discussed an extremely promising and innovative type of intervertebral disc surgery called thermodiscoplasty, which involves an endoscopic laser disc shrinkage with tightening effect. Electrothermal microdecompressive disk surgery is for symptomatic herniated discs. Dr. John Chiu explained that open spinal discectomy is associated with significant local morbidity and long-term convalescence, hence the search for less traumatic surgical procedures. These have included percutaneous and conventional endoscopic methods and also chymopapain (despite an excessive risk of anaphylaxis and neurological complications, this presenter feels there is still a place for chymopapain). Although Dr. Chiu still does lots of open surgery in his clinic, where possible he uses nonablative laser treatment to shrink the disk, with a pulsed laser used at various energy levels. Heating effects shrinkage of 25-30% with tightening and reshaping. After treatment and shrinkage, the tensile strength of the disk is actually improved. Strict patient selection is crucial to the overall of the clinical protocol. Patients who initially have good results are likely to do well in the longer run as well. A typical patient receives some 12 weeks of conservative care prior to surgery. Ideally there should not have been previous back surgery. Cervicogenic headache cases have done especially well.

Dr. Anthony Yeung, after commenting that Dr. Chiu is a black belt both in martial arts and in surgery, discussed his own prospective study on the treatment of lumbar annular tears using similar electrothermal methods. Whereas Dr. Chiu spoke more to the surgical procedure itself and outcomes to date, Dr. Yeung went more into the pathophysiology of low back pain as it relates to disk herniations. Although it has been far from obvious why annular tears hurt some people and not others, an understanding has gradually emerged that there are many types of disk damage, each producing characteristic symptoms. Radial fissures that reach the outer 1/3 of the annulus are the real pain producers, much more so than even large disk bulges. Zone 3 patterns of disk damage produce atypical pain in a nondermatomal distribution, sending unfortunate patients with real, organic back pain into a medical system that has been overly quick to judge them as symptom magnifiers: you know, Wadell types. The chemically sensitive disk (Derby) results in pain levels not in obvious proportion to the size of the structural damage. Dr. Yeung finds Chiu's laser ablative "sexy but unnecessary," and uses instead "targeted heat" (electrically heated coils inserted into the disk, I think) to accomplish the same task. He hopes that in the future, surgeons will be able to identify annular tears that are most likely to respond to electrothermal energy, and reserve fusion for the more appropriate indications of instability and deformity.

Dr. Pope returned to discuss the role of thoracocervical musculature in whiplash injuries of the neck. He performed cervical EMG (SCM, trapezius, levator, splenius capitis and semispinalis capitis) during low-speed rear impacts (cf. Pope, Hasselquist, Bolte, et al). It is commonly believed that muscle reaction time is too long to be a factor in the injury, given the shorter rise times of the loads that cause injury. This study showed that the muscles with the longer moment arms had shorter reaction times, appearing to provide a significant stabilizing effect on the subject. The response, which appeared to be somatosensory rather than visual, was fast enough to have an influence on the injury pattern. Indeed, some injuries may result from eccentric contractions of the musculature, meaning muscle involvement during whiplash may to some extent be a disadvantage.

Finally, one speaker, an expert in manual medicine, was jokingly introduced as a "postsurgical presenter" in that he had just undergone surgery on his lumbar spine. I couldn't help recalling that this same speaker just a few years ago had used himself to make a point about how frequently a patient's clinical presentation is dissonant with the x-ray. At that time, exhibiting lumbar x-rays quite riddled with degenerative joint disease, he had asked -- on that basis alone -- what "procedure" should be done. As soon as the surgeons had sufficiently indulged in the bait, offering up a variety of suggestions for various surgeries, this presenter shocked everyone by divulging these x-rays to be of his own spine. He then chided the surgeons for (you know the refrain) being so quick to "treat the image, not the patient," who was doing quite well with exercise, etc. Now that this doctor, who once seemed to think his own x-rays somewhat irrelevant, has undergone surgery, I wonder if his views have changed.

Closing quote: someone during the conference said, "Everyone's favorite treatment works short-term." Ain't it the truth!

References

  1. Chapman-Smith D. Complementary and alternative medicine (CAM). The Chiropractic Report 1999;13(2):1-3, 6-8.
  2. Mixter WJ, Barr JS. Rupture of intervertebral disc with involvement of the spinal cord. New England Journal of Medicine 1934;211:210.
  3. Cooperstein R. ABS meets in San Francisco. Dynamic Chiropractic, February 25, 1994:22, 32, 33-34.
  4. Cooperstein R. ABS update. Dynamic Chiropractic May 6, 1994:28, 30.
April 1999
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