Early Imaging for Low Back Pain: more harm than good?
Friday, February 4, 2011 at 12:00AMA recent study considered the question of whether people with work-related low back pain who get an early MRI do better. Most people would think that a picture of the back and what is going on would be nothing but helpful. I get people in the office all the time that “want to the know what the problem is.”
Interestingly, though, the study found that in the “majority of cases had no early MRI indications.” More striking, the study found that getting an early MRI resulted in “worse disability and increased medical costs and surgery, unrelated to severity.”[i]
Other studies have demonstrated similar effects.
A meta-analysis of 6 randomized trials (6), which comprised 1804 patients with primarily acute or subacute low back pain and no clinical or historical features that suggested a specific underlying condition, found no differences between routine lumbar imaging (radiography, MRI, or CT) and usual care without routine imaging in terms of pain, function, quality of life, or overall patient-rated improvement (Table 3). For short-term outcomes (3 months), trends slightly favored usual care without routine imaging.[ii]
There are a number of reasons why imaging is not beneficial in most cases.
For one reason, so-called “abnormalities” on imaging are common in people without low back pain and are only loosely associated with back symptoms. [iii] “In a cross sectional study, 36% of asymptomatic persons aged 60 years or older had a herniated disc, 21% had spinal stenosis, and more than 90% had a degenerated or bulging disc. A prospective study (32) found that among patients with lumbar imaging abnormalities before the onset of low back pain, 84% had unchanged or improved findings after symptoms developed.” [iv]
Imaging can also lead to potentially unnecessary procedures. If we see a “herniated disc” on MRI, this visual evidence frequently leads to a desire to “cut out” or surgerized the offending abnormality on MRI. “The association between rates of advanced spinal imaging and rates of spinal surgery seems strong. In a randomized trial, patients with low back pain who had rapid MRI had spine surgery about twice as often as those who had radiography. [v] Another study (51) found that for work-related acute low back pain, MRI within the first month was associated with more than an 8-fold increase in risk for surgery and more than a 5-fold increase in subsequent total medical costs compared with propensity matched control patients who did not have early MRI.” [vi]
Following is a copy of the revised guidelines for imaging of the lumbar spine from the American College of Physicians (http://www.annals.org/content/154/3/181.figures-only)
[i] J Occup Environ Med. 2010 Sep;52(9):900-7
[ii] Ann Intern Med. 2011;154:181-18
[iii] Ann Intern Med. 2011;154:181-18
[iv] Ann Intern Med. 2011;154:181-18
[v] Ann Intern Med. 2011;154:181-18
[vi] Ann Intern Med. 2011;154:181-18
Reader Comments (1)
It is very possible that an MRI would not show the damage because the injury has not been aggravated. The MRI will only show what is there, not what develops after the fact. Almost all work-related back injuries are the culmination of months or years worth of bad practices, sleeping positions, etc. Always get an imaging scan in the case of an injury. Better safe than sorry.