Decoding Lower Back Pain

Two key questions that doctors working in the spinal community have long sought to answer are “what generates the pain” and “what technologies and treatments will provide relief.”  Figuring out the exact sources of lower back pain has been akin to reading Egyptian hieroglyphs prior to the discovery of the Rosetta Stone. In 2008, companies in spine and related biologics rang up over $8 billion in revenues attempting to answer those two questions. Is the money being spent in the right places?

The Elusive Causes of Low Back Pain

The literature from the spinal community is full of examples of the challenges physicians encounter in diagnosing acute/non-specific lower back pain.

In an article in the Journal of General Internal Medicine, published in February 2001, entitled “Evaluating and Managing Acute Low Back Pain in the Primary Care Setting, ” Drs. Steve Atlas and Richard Devo speak to the heart of the issue. “Despite large differential diagnosis, ” they write, “the precise etiology is rarely identified, although musculoligamentous processes are usually suspected.” They continue, “Even when back pain is associated with specific imaging findings such as degenerative disc disease, spondylolysis, spondylolisthesis, or osteoporosis, it may be impossible to determine whether the finding is the cause of the patient’s symptom.”

Donald Murphy, D.C. and Eric Hurwitz, Ph.D., D.C, in an article published August 3, 2007, in Biomed Central Musculoskeletal Disorders  titled “A theoretical model for the development of a diagnosis-based clinical decision rule for the management of patients with spinal pain” note, “It has been repeated over the years that only in 15% of patients with spinal pain can a definitive diagnosis be made.”

In an article published June 14, 2007, in the European Spine Journal titled “Systematic review of tests to identify the disc, SIJ or facet joint as the source of low back pain, ”  by M.J. Hancock, C.G. Maher, J. Latimer, M.F. Spindler, J.H. McAuley, M. Laslett, and N. Bogduk, the authors raise questions regarding other diagnostic tests. “It appears, ” they write, “that only a small amount of investigation has been performed into the diagnostic accuracy of clinical tests to identify the tissue source of low back pain. There are tests for the disc and SIJ that have some diagnostic value but no test for the facet joint that appears informative. The usefulness of these tests in clinical practice, particularly for guiding treatment election, remains unclear. Further quality investigation into tests that appear promising is required.”

Despite a mountain of diagnostic tools and tests, the actual source of lumbago, or lower back pain, remains frustratingly difficult for clinicians to diagnose.

Current Diagnostic Test Usage and Procedures by CPT Code

Surgeons and clinicians can choose from a litany of diagnostic tools. Each has it is own advantages and disadvantages, but which tools do doctors use most?

Imaging Studies

Common imaging studies in spine include plain radiographs (X-rays), magnetic resonance imaging, (MRI) and computer tomography (CT). Clinicians and surgeons utilize all three tools to diagnose the cause of low back pain. By compiling CPT codes related to these imaging studies, the PearlDiver Patient Records Database can be used to find trends among 2.7 million patients who underwent a spine-related MRI, CT scan or X-ray. The CPT code ranges in this analysis are as follows:

X-Ray Codes: 72020-72120

CT Codes:  72125-72133

MRI Codes: 72141-72295

As one would expect, X-rays were the most commonly used diagnostic tool in spine, accounting for 61.4% of the imaging studies. MRIs accounted for 33.8% and CT scans registered 4.8%.

X-rays by Region of the Spine

According to the data, 45.4% of all spinal X-rays were coded as being over the lumbar region of the spine. This was followed by X-rays of the cervical spine at 31.4%. Chart 1 provides a breakdown of X-rays over the various regions of the spine.

Chart 1: Spine X-rays by Region of the Spine

Source: PearlDiver Patient Records Database 2004-2007

Are X-rays the best front line diagnostic to help identify pain generators? They are certainly the most common. At the primary care level, X-rays are used to rule out serious causes of low back pain. However, they are not particularly useful as a diagnostic tool in finding the cause of low back pain. Deyo and Atlas explain: “imaging findings are poorly associated with symptoms, and important causes cannot be identified with pain radiographs.”

Lumbar disc degeneration and herniation are the two most common diagnoses in spine patients under 65 years of age, according to the PearlDiver database. In their article, Deyo and Atlas state that “lumbar disc herniation or spinal stenosis are radiographically detected only with advanced imagine techniques such as CT or MRI.” Even though doctors use X-rays the most, this tool is no Rosetta Stone for decoding back pain.

MRI and CT

MRIs are the second most common imaging study. The lumbar region of the spine comprises 58.9% of all spinal MRIs, followed by the cervical region (33.1%) and the thoracic region (8%). The distribution by region was relatively constant from 2004-2007. MRIs may be the most useful in spine because they can be used to help identify potential causes of mechanical low back pain. They are often the imaging study of choice when it comes to nerve root impingement.

CT is the third most common study performed and is unique in that it can take cross section images of the body. In our analysis, we examined CT usage by region of the spine from 2004 through 2007. CT use in the lumbar region declined from 58.2% in 2004 to 51.2% in 2007. During the same period usage in the cervical region increased from 34% in 2004 to 39% in 2007. Usage over the thoracic region has also increased annually. The overall trend is displayed in Chart 2.

Chart 2:  CT by Region of the Spine

Source: PearlDiver Patient Records Database 2004-2007

Other Diagnostic Tools

While the majority of patients afflicted by low back pain will recover within four to six weeks, those with persistent pain eventually will undergo one of the above diagnostic imaging studies. Although current technology focuses on the various anatomic views of the spine, there are a myriad of other tests including:

• Discography/discogram
• Provocative discography
• Myelography/myelogram
• Diagnostic selective nerve root block (injection studies)
• Bone scan
• Electrodiagnostic tools

Even though the data shows that X-rays, CT scans and MRIs are the most commonly used diagnostics, the literature points out that these tools often fail to address the specific physiology associated with low back pain. Nevertheless, the spine industry is collecting over $8  billion dollars in annual revenues treating back pain for which physicians are not always sure of the cause.

The SpineMatrix Solution

Exhibit 2:  Patient Undergoing
a SpineMatrix diagnostic study

Source: SpineMatrixSpineMatrix was founded in 2003 and is based in Akron, Ohio. The company is led by CEO Ben Shappley, an industry veteran with over 25 years of orthopedic experience. Using technology called CERSR (computerized electrophysiological reconstructed spinal regions) the company has developed the Lumbar Matrix Scan to help physicians differentially diagnose lower pack pain by allowing the physician to see the physiology associated with the pain. An array of 63 sensors placed on the back allow the physician to study neuromuscular activity in real time. The technology is patented and FDA cleared for diagnostic use. The full test takes just 15 minutes and is comprised of nine studies of the back. The ability to non-invasively diagnose and differentiate between discogenic, facet and muscular back pain is a remarkable technological development. Ten peer-reviewed clinical papers report that the Lumbar Matrix Scan is a safe, non-invasive, accurate and effective diagnostic procedure.

Does this technology have the potential to become the standard of care?  Investors think so. SpineMatrix closed $8 million in financing in June 2007, lead by New York City-based Psilo Group.

The ScoliScore Test

Axial Biotech, based out of Salt Lake City, Utah, also has a new diagnostic tool for decoding back pain in patients with scoliosis. John Climaco, CEO and President of Axial Biotech, seeks to tackle scoliosis through genetics.

ScoliScore is a clinically validated, multi-gene test that provides a qualitative and quantitative assessment of the likelihood of spinal curve progression for patients who have been diagnosed with adolescent idiopathic scoliosis (AIS). This is part of a growing trend in spine which focuses on diagnosing and treating spinal disorders earlier in the continuum of care. Axial is taking one step further by actually attempting to predict the likelihood of spinal curve progression.

ScoliScore was developed by utilizing a genome-wide association study that identified a panel of 53 genetic markers associated with severe curve progression. This scoliosis research involved collecting DNA samples from over 9, 500 patients from 85 clinical sites. The test has been validated in two separate clinical trials.

ScoliScore is intended for patients:

• With a primary diagnosis of (AIS)
• Between the ages of 9 and 13 years old
• With a mild scoliotic curve (defined as <25°), or
• With a moderate scoliotic curve (defined as >25°, but less than 40°)

If the test predicts that a patient may have AIS, what do physicians do next? Once physicians know a patient will have curve progression, is there a treatment to stop it? Do bracing or non-fusion spine surgeries work in these patients? These questions should be central to future studies.

Axial Biotech has an interesting plan for the future as well, with a product pipeline centered around predictive tests.  

The pipeline includes the development of DNA-based tests in:

• Degenerative disc disease
• Spondylolisthesis
• Scheuermann's disease
• Osteoarthritis
• Osteoporosis

The Rosetta Stone of Low Back Pain

Identifying the exact pain generators that cause low back pain will continue to challenge clinicians. While X-rays, MRIs and CT scans will always aid in the diagnosis, new and advanced technologies, such as those developed by SpineMatrix and Axial Biotech, may provide surgeons with the long-sought Spine Rosetta Stone, which would allow clinicians to accurately identify the exact cause of low back pain for each patient. 

For more articles by this author, please select the following link: http://www.pearldiverinc.com/pdi/spine.jsp.