No Imaging Needed for Most Low Back Pain in Teens

Medscape Medical News from the:American Academy of Pediatrics (AAP) 2011 National Conference and Exhibition November 1, 2011 (Boston, Massachusetts) — Most cases of low back pain in children will get better with conservative management and do not need to be diagnosed with radiographic studies, researchers said here at the American Academy of Pediatrics (AAP) 2011 National Conference and Exhibition. Mechanical low back pain is common in the pediatric population, and recent studies have shown that undiagnosable mechanical low back pain accounts for up to 78% of cases in adolescents. The most common pathologic cause of back pain in this age group is spondylolysis and spondylolisthesis, senior author Denis Drummond, MD, from the Children’s Hospital of Philadelphia, Pennsylvania, said. Low back pain can appear very serious when a child presents, and kids can end up getting a big work-up with too many imaging studies, Dr. Drummond told Medscape Medical News.This exposes them to too much radiation, he said. "It’s bad enough to give radiation to an adult, but a child absorbs more and their metabolism is much greater than an adult’s. Radiation is accumulative and kids with low back pain get imaged close to the pelvis, which exposes the ovaries, bladder, and colon to potentially dangerous doses," he added. In the current study, Dr. Drummond and his team retrospectively reviewed the records of 2846 children aged 10 to 19 years who were seen at their institution with low back pain between 2000 and 2008. Most (63%) were female, and the average age was 14 years. In 79% of the patients (n = 2244), the cause of their low back pain went undiagnosed. Over 90% had 3 or fewer office visits. Spondylolysis, which was diagnosed in 272 patients (9.6%), was found by plain radiography in 234 patients (86%), by bone scanning in 34 patients (12.5%), and by computed tomography (CT) in 4 patients (1.5%). Two-view and 4-view radiography was equally sensitive in diagnosing spondylolysis. The sensitivity of 2-view was 78%, and that of 4-view was 72% (P = .39). The researchers also found that bone scans delivered significantly more radiation than both CT and 2- and 4-view radiography. "We didn’t think that bone scans would be associated with so much radiation when we started this study. But it turns out that it was the worst of all the imaging modalities. The dye from the scan sits in the bladder for 24 hours and that is enough to change some cells if done often enough," Dr. Drummond commented. "When we presented this, people said ‘Holy cow! I didn’t know bone scans were associated with so much radiation,’ and they told me they were now going to consider giving up doing them," he said. "Our message is try and treat the low back pain conservatively. If you want, you can do a 2-view x-ray at the first visit or else put them on physical therapy, and be patient. If they are 50% to 60% improved when you see them in 6 weeks, you’re probably on the right track. If the pain is all gone at 3 months, get them ready to go back to sports or usual activities. If there is just as much pain at 6 weeks, go back to the old system of more investigation, but the majority will get better by then," he said. American Academy of Pediatrics (AAP) 2011 National Conference and Exhibition; Abstract #14782. Presented October 14, 2011.