Low Back Pain May Be Predictable, NASS Study Says

At the annual meeting of the North American Spine Society (NASS), this year held in New Orleans, La., one of the papers named “Best Paper” by The Spine Journal introduced a surprising new idea: that lower back pain could be predicted before onset.

“It’s exciting to think that spine specialists could have a simple tool to predict a patient’s future lower back pain and its severity before the patient actually experiences the pain,” said Matthew Smuck, M.D., chief of physical medicine and rehabilitation at Stanford University Medical Center and NASS annual meeting program co-chair. “This large, well-crafted study opens up a world of thinking when it comes to preventing pain before it starts for millions of patients.”

“Prediction of Future First-Time Low Back Pain Based on Baseline MRI Findings” was a prospective study of 248 asymptomatic patients. The authors concluded that MRIs (magnetic resonance imaging) could determine subtle spine changes in patients without back pain and provide a way to predict the onset and severity of lower back pain.

Previous studies on this topic showed degenerative changes on MRI did not predict future back pain in asymptomatic individuals. However, the authors point out that these past studies presented small sample sizes, did not thoroughly assess various imaging and demographic phenotypes related to pain and were heterogeneous.

In response to these previous limitations, the authors assembled 248 asymptomatic Southern Chinese patients, 93 males and 155 females, with a mean age of 42.9 years, with no previous history of lower back pain (LBP). All the subjects underwent sagittal MRI assessment of the lumbar spine. A degenerative disc disease (DDD) score of the lumbar spine was calculated, representing the global severity of disc degeneration. A degenerative disc disease (DDD) score of the lumbar spine was calculated, representing the global severity of disc degeneration. The presence of disc bulge/extrusion, Schmorl’s nodes (protrusions of the cartilage of the intervertebral disc into the adjacent vertebra) and Modic changes (pathological changes in the vertebrae) were also noted. Clinical assessment was performed at a two-year minimum follow-up, and subject demographics were noted to identify the development of LBP and functional outcome status.

Overall presence of disc degeneration, disc space narrowing and disc bulge/extrusion was noted in 60.5 percent, 19 percent and 34.3 percent of patients respectively. Schmorl’s nodes and Modic changes were noted in 10.5 percent and 1.2 percent, respectively. Clinical follow-up was performed at a mean of 4.3 years. The incidence rate of first-time LBP episodes on clinical follow-up was 34.7 percent. The mean age of first-time LBP episode was 44.8 years. Regression modeling noted that the presence of disc bulge/extrusion and increasing DDD score, in particular if segments involved the mid lumbar region, demonstrated significant predictive utility for developing first-time LBP episode. Study authors found that DDD score and disc bulge/extrusion were predictive to the severity of LBP, greater functional disability and increased frequency of future LBP episodes.