Distinguishing scintigraphic features of spondylolysis.

A scintigraphic pattern of increased uptake was observed in the pedicles of the affected segment and a triangular pattern of uptake in the sagittal projection of tomographic studies of pars fractures. It was hypothesised that these observations were specific for pars fractures. A retrospective study of 25 young athletes (age 9-16 years) with a variety of spinal disorders was undertaken. Back pain was present for an average of 4 months. Diagnosis was confirmed by radiologic studies and/or response to treatment. All 15 children with spondylolysis had evidence of increased uptake in the ipsilateral or contralateral pedicle. None of the other causes of back pain showed this pattern. A specific triangular pattern of uptake was seen in the sagittal view in these patients. The authors describe two unique features of spondylolysis that add to the confidence with which the scintigraphic diagnosis may be made.