Adolescent stress fractures of the sacrum: two case reports.

Two teenage female athletes had low back pain that limited athletic activity. Radiographic examination was negative. A stress fracture of the ala of the sacrum was identified on bone scan and computed tomography (CT) scan. The lesions healed with rest. This unusual lesion has not been reported previously in the pediatric literature, but is probably more common than its lack of documentation suggests. Careful observation and evaluation of athletic individuals will enable identification of this lesion. Rest should allow fracture healing, followed by return to sports participation. Stress fractures of the sacrum should be included in the differential diagnosis of adolescent low back pain.