[Osteoid osteoma of the femur neck in children and adolescents. Apropos of 12 cases].

Specific characters of the osteoma osteoid as a beniGN tumor are well known. We report twelve cases of femoral neck localisation. Delays in diagnosis of six months to one year after the onset of symptoms are quite common. Chronic or recurrent pain is localised in the inguinal area with a projection to the leg and to the knee. The pain was relieved by Aspirin in six cases only. X ray of the pelvis antero-posterior showed the tumor, but did not always show the lucent image with the surrounding sclerotic area that is well observed with tomography. The scintigraphy with technetium 99 is perhaps more sensitive as a way of diagnosis. The lesion is the place of intensive uptake. Although the surgical excision "in block" and the replacing of bone graft and material of osteosynthesis gave positive results, many technical problems are present during the intervention because of the important cortical reaction and bone densification. In six cases, peroperative X Ray and histology did not give diagnosis.