Unlike in adult medicine, low back pain is an unusual chief complaint in pediatric practice, and the majority of pediatric cases have an identifiable cause. Most cases are caused by musculoskeletal disease or trauma; however, clinicians must consider more systemic conditions, such as infection, noninfectious inflammatory disease, and neoplasm.

The most common cause of back pain is mechanical. Strains and sprains are treated with rest and simple analgesics, and typically improve in 2 to 3 days. Direct traumatic injuries are also common, and the history guides the clinician to these diagnoses.

Spinal developmental abnormalities that may cause back pain include spondylolysis and spondylolisthesis. Spondylolysis is caused by a stress or fatigue fracture or separation of the pars interarticularis, often in L5. It is more common in sports that emphasize hyperextension of the spine, such as gymnastics, tennis, and weight lifting. The defect appears as a radiolucent line around the “Scottie dog’s” neck on oblique radiographs. Bilateral spondylolysis can lead to spondylolisthesis in which the proximal or cephalad vertebral body is ventrally subluxed over the next most caudal vertebral body. A patient with negative radiographs but pain on hyperextension and a classic history needs further imaging, such as with a computed tomography scan or bone scan. Treatment of spondylolisthesis includes bracing, for early lesions; and fusion surgery, for patients with progression of the subluxation or neurologic signs; followed by physical therapy with core body exercises.

A child with the sudden onset of severe back pain, fever, and an elevated erythrocyte sedimentation rate may have an infection. Discitis and vertebral osteomyelitis are two conditions to consider, with the former being more common in children older than 8 to 10 years and the latter being more common in children older than 8 to 10 years. As routine radiographs can appear normal early on in the disease, magnetic resonance imaging is the
test of choice; a bone scan is also frequently diagnostic. Treatment of both infections includes bed rest and antibiotics.