MRI For Low Back Pain: When Is It Too Early?

Workers who have an acute low back injury with pain while on the job are often anxious to get back to work. Current Clinical Practice Guidelines (CPGs) recommend that only certain patients require X-rays. This is also true for other imaging studies such as MRIs in the first six weeks after injury. Even so, research shows a high rate of early MRI among Workers’ Compensation patients.

This is the first study to look at factors that might account for the early use of imaging for injured workers. Over 1,800 working adults who filed a claim for a back injury were included. All kinds of data about the workers was collected and analyzed. For example, age, race/ethnicity, level of education and income, and marital status were some factors considered.

Other characteristics that might influence the decision for early imaging were also considered. These included general health, job satisfaction, previous Worker Compensation claims, and type of employment. And finally, information on injury severity, level of pain, and patient-reported disability were also evaluated.

As it turns out, the authors of this study were able to identify what they called red flags for serious back pain. These are patients who are more likely to need early imaging studies. Age (younger than 20 and older than 50) was one important clinical characteristic. Spinal tumor, bone fracture, or infection were the main concerns. Any other signs or symptoms common with these three conditions were also considered red flags.

A second important finding from this study was more specific to the question of: Who is getting an early MRI for acute low back pain? The answer: men, workers with high levels of fear of reinjury, and greater injury severity and disability. Workers who had the lowest rate of early MRIs were first seen for their low back pain by a chiropractor. In contrast, workers who went to a medical doctor (general practitioner, neurologist, or orthopedic surgeon) were the most likely to receive an early MRI.

How did the authors explain their findings? First, some medical doctors routinely order MRIs right away — even though current evidence doesn’t support this practice. Second, chiropractors rely on X-rays taken in their offices rather than on MRIs provided somewhere else. And third, workers who are afraid to go back to work for fear of reinjury make up a large percentage of patients who have an MRI for an acute episode of injury-related back pain.

The results of this study point out again that medical costs can be lowered by following evidence-based recommendations. All physicians have access to the Clinical Practice Guidelines (CPGs) on Low Back Disorders published by the American College of Occupational and Environmental Medicine. In the case of mechanical low back pain from acute injury, conservative care is recommended. Early imaging is not advised unless there are red flags or neurologic signs and/or symptoms.