Abstract
We treated seven cases (5 males and 2 females) of osteoid osteoma, and examined their preoperative radiological findings and surgical results. The mean age of patients was 16 years (range 9-25 years). The location of tumor was intracortical area of femur in 6 cases and intramedullary area of tibia in 1 cace. Resection of nidus and iliac bone graft were performed in 6 cases and resection of nidus alone in 1 case. There was no local recurrence and preoperative rest pain and nocturnal pain in all cases disappeared after operation.
On preoperative computed tomography, identification of nidus was possible in all cases, but on preoperative radiogram, small nidus less than 5mm in 3 cases were not demonstrated. We examined pre- and post-operative MRI in 3 cases. The intramedullary high intensity area adjacent to the intracortical nidus on preoperative T2-weighted image was diminished after operation in all 3 cases.
The mechanism of intramedullary edematous change adjacent to the cortical nidus is still unknown. However, the postoperative MRI findings in the present study suggest that production of prostaglandins in the nidus, as Greco reported in 1991, or cytokines, such as interleukins may be associated with the pathogenesis of osteoid osteoma.
