Suspecting lumbar spondylolysis in adolescent low back pain.

Spondylolysis in the athletic adolescent and preadolescent is common enough that primary care practitioners should be familiar with its frequency and its progression from pars interarticularis stress fracture to spondylolysis and to spondylolisthesis. One-half of all pediatric back pain in athletic patients is related to disturbances of the posterior elements including spondylolysis, which presents as low back pain aggravated by activity, frequently with minimal physical findings. Failure to suspect, hence to diagnosis, a pars stress fracture or early spondylolysis is common and a misdiagnosis of lumbosacral strain is often made. A complicating factor in early diagnosis is the fact that plain radiographs, even with oblique films, may not be helpful at the stress fracture stage, and other imaging techniques (bone scan possibly with single photon emission computed tomography [SPECT]) must be used early in the diagnostic process. In the primary care setting, an early diagnosis of posterior element involvement in low back pain either at the stage of pars stress fracture or early spondylolysis can prevent progression of the disease and the need for aggressive intervention for a more significant defect. We present three adolescent and preadolescent athletes with low back pain in whom a high index of suspicion led to the early diagnosis of pars stress fracture or spondylolysis. All three had different stages of spondylolysis, and one illustrates the clinical utility of the one-legged hyperextension test. The ease with which early disease may be treated further supports efforts by primary care practitioners to suspect and diagnose pars stress fracture and early spondylolysis.