Mathis JM, Golovac S, eds.  Image-Guided Spine Interventions.  2^nd ed.  Springer 2010, 403 pages, 281 illustrations, $199.

For spine interventionalists it could be said these are the “best of times and the worst of times.” Over the last 25 years, the practice of minimally invasive image-guided spine therapy has experienced remarkable growth. An ever-growing cadre of practitioners and dedicated academic programs are now devoted to advancing minimally invasive therapies for back pain, which many now consider a medical “epidemic” with costs exceeding $100 billion per year in the U.S. alone.

And yet any honest spine therapist should be willing to admit that much of what we perform and promulgate remains inadequately supported by Level 1 evidence.  Although many areas of medicine also share in this deficiency, the problem for image-guided spine therapy may be especially entrenched.  The relative dearth of well-designed randomized controlled trials (RCTs) is no doubt due in part to limited funding opportunities outside of industry.  Regardless, there is also unquestionable apathy among practitioners to pursue such studies.  A cynic would probably argue that scientific inertia among spine interventionalists is a direct consequence of economic drivers.  I would argue that a bigger influence is actually the daily experience of minimally invasive spine therapists.   Immediate life-changing improvements in patients are commonplace. These experiences understandably compel most practitioners—as well as their patients—to conclude that the specific therapeutic efficacy of their procedures is self-evident and requires no further study.

In the midst of this evolving cognitive dissonance in spine therapy, we now have another new review: Image-Guided Spine Interventions, 2^nd edition, edited by Drs. John Mathis and Stanley Golovac. The editors each have practices devoted solely to spine procedures and pain management, and have assembled a solid group of colleagues from a mix of academic and busy private practices in the U.S to contribute chapters on specific image-guided interventions.  Overall, each contribution is technically well written, and many of the figures throughout the book are original and of high quality.  The latter in particular lends itself to the book’s primary value as a short, handy reference for a few spine procedures currently in practice. The book is small, portable, and can be thumbed through quickly when one is, say, short on time and in need of an anatomical reference relevant to a specific procedure.

Aside from this possible utility, however, it is difficult to recommend this book on any other grounds.  Each chapter devoted to a given procedure is neither sufficiently detailed nor appropriately referenced to serve as a primary resource.  Interventionalists-in-training will be better served referencing more comprehensive guides such as Slipman et al’s Interventional Spine: an algorithmic approach and Fenton and Czervionke’s Image-Guided Spine Intervention.

For someone on the outside interested only in a short introduction to the field, Mathis and Golovac’s book is even more problematic. The choice of reviewed procedures is neither comprehensive nor accurately representative of those most commonly performed in a typical spine intervention practice.  Relatively established and common procedures such as trans-foraminal epidural injections (“nerve root blocks”) and radiofrequency facet joint denervation (“facet rhizotomy”) are not even addressed. On the other hand, discography, a controversial procedure with virtually no diagnostic relevance (especially now that surgical fusion for axial “discogenic” back pain is no longer indicated), gets its own chapter, as does percutaneous lumbar discectomy, which has long been discounted.  Dedicated chapters on bone biopsies, endovascular therapy of vascular disease, and implantable spinal cord stimulators are also questionably included, since these procedures fall outside the purview of most minimally invasive spine practices dedicated to pain management.

One of the more informative chapters is by Dr. Wetzel on the surgeon’s perspective, although not because it discusses to any significant degree the actual relationship between image-guided therapy and surgical management; rather, it is virtually the only place in the book where the evidence, or lack thereof, for various image-guided interventions is substantially reviewed.   The validity and utility of virtually every intervention addressed in subsequent chapters is often and appropriately called into question. Unfortunately, only 8 of 108 references are from after 2002, and no studies after 2006 are referenced.  This contribution is arguably the most important of the book, and the reader deserves a more up-to-date treatment of these critical issues.  This is an unfortunate failure on the part of the author and the editors.

In my own image-guided spine therapy practice, I am constantly amazed and gratified as patient after patient enters my office after months of misery and lost sleep and walks out miraculously pain-free.  I have empathy, therefore, with the multitudes of practitioners who express their incredulity with the results of two recent randomized controlled trials suggesting that the dramatic pain response observed with vertebroplasty is due entirely to a “placebo effect” rather than cement injection.^1,2  This frustration is revisited again in Mathis and Cho’s chapter on vertebroplasty.  For those of us who observe life-transforming changes in patients on a daily basis, it is hard to rationalize “placebo efficacy.” Yet if we step back and accept the power of well-designed prospective RCTs, which are never perfect but still provide the highest level of evidence, we should be compelled to at least review the remarkable and substantive history of placebo therapy.  A recent highly recommended and fascinating account by Michael Spector details the history, beginning substantively with the work of Colonel Henry Beecher, the first chair of anesthesiology at MGH.³ Dr. Beecher was initially perplexed by the differential responses of gravely wounded soldiers who would recurrently refuse morphine versus healthy soldiers who would complain incessantly about pain from minor inconveniences like vaccinations.  He concluded, impressively, that our expectations have a profound impact on how we perceive pain and on how we heal.  Indeed, the vertebroplasty versus sham RCTs previously mentioned are hardly unique, with analogous studies (and similar results) reported for chemonucleolysis,⁴ intradiscal electrothermaltherapy(IDET),⁵ arthroscopic knee surgery,⁶ and several other interventions.   It’s not that the pain isn’t real; it’s also not that the placebo response isn’t real. Indeed, objective physiological and neurological responses to placebos have been repeatedly observed using functional MRI, biochemical analyses, and may even be blocked pharmacologically using receptor antagonists to endogenous opiods.

As a profession moving forward we must not be afraid to ask the hardest questions, even in the face of apparently obvious therapeutic efficacy, and work towards a solid foundation of evidence-based rather than anecdotal or economically driven clinical decision-making. Otherwise, in this age of contracting resources, the public will eventually take it upon themselves to impose even more regulation on clinical practice, further removing whatever remains of our autonomy.  Books such Mathis and Golovac’s Image-Guided Spine Interventions do little to advance our field, nor do they provide a foundation moving forward.  Until well-known and respected practitioners of minimally invasive spine therapy take upon themselves to ask the hard questions, to be self-critical, our field will remain forever grounded in an “age of wisdom, and of foolishness…with everything before us, and nothing before us.”

References

1. Kallmes DF, Comstock BA, Heagerty PJ, et al. A Randomized Trial of Vertebroplasty for Osteoporotic Spinal Fractures. NEJM 2009;361:569-79.
2. Buchbinder R, Osborne RH, Ebeling PR, et al. A Randomized Trial of Vertebroplasty for Painful Osteoporotic Vertebral Fractures. NEJM  2009;361:557-68.
3. Specter M. The Power of Nothing. The New Yorker  December 12, 2011:Annals of Science, 30-6.
4. Schwetschenau PR, Ramirez A, Johnston J, et al. Double-blind evaluation of intradiscal chymopapain for herniated lumbar discs: Early results. J Neurosurg 1976;45:622-7.
5. Freeman BJ, Fraser RD, Cain CMJ, et al. A Randomized, Double-Blind, Controlled Trial: Intradiscal Electrothermal Therapy Versus Placebo for the Treatment of Chronic Discogenic Low Back Pain. Spine 2005;30:2369-77.
6. Moseley JB, O’Malley K, Petersen NJ, et al. A Controlled Trial of Arthroscopic Surgery for Osteoarthritis of the Knee. NEJM 2002;347:81-8.