Reactive sclerosis of a pedicle and spondylolysis in the lumbar spine.

Eleven patients were seen with reactive sclerosis and hypertrophy of one pedicle and lamina of a lumbar vertebra and a contralateral spondylolysis in the same vertebral segment. Differentiating the reactive sclerosis in this condition from that associated with osteoid-osteoma is necessary since excision of a sclerotic pedicle associated with contralateral spondylolysis will create painful instability. In asymptomatic patients observation is sufficient, while in those with symptoms not relieved by external immobilization, spine fusion, usually of three levels, is indicated.