Bradford A. Kilcline, MD

ABSTRACT: Unless the cause of back pain is obvious, order anteroposterior and lateral radiographs of the spine, a complete blood cell count, erythrocyte sedimentation rate, and urinalysis. If you suspect infection, tumor, or bony abnormalities, obtain an MRI or CT scan. MRI has surpassed bone scanning as the gold standard for diagnosing spinal infections, because it confirms a specific anatomic diagnosis. Spondylolysis and spondylolisthesis are 2 of the most common causes of back pain in adolescents; the diagnosis is made with plain radiographs, which show slippage on the later-al view in patients with spondylolisthesis and fracture through the pars interarticularis on the oblique views in those with spondylolysis.

Although acute low back pain usuallyresolves within 6 weeks-with or withouttreatment-the pain may signal asignificant neurologic or life-threateningdisease that warrants immediateintervention.

ABSTRACT: A focused history taking and physical examination directed toward uncovering signs that suggest a serious underlying cause of low back pain are crucial. "Red flags" include pain that lasts more than 6 weeks; pain in persons younger than 18 years or older than 50 years; pain that radiates below the knee; a history of major trauma; poor rectal tone; constitutional symptoms; atypical pain (eg, that which occurs at night or that is unrelenting); the presence of a severe or rapidly progressive neurologic deficit; and a history of malignancy. These markers provide a cost-effective means of guiding your selection of laboratory and diagnostic imaging studies.