Bone cement, thermal injury and the radiolucent zone

Six patients, with giant cell tumors of bone treated by curettage and bone cementing, were followed radiographically for 4 (2-6) years postoperatively. The radiolucent zones between cortical bone and cement increased in width up to 0.5 mm during the first 6 months and then remained stationary. During the same period the zone adjacent to cancellous bone increased up to 2.5 mm and was surrounded by a sclerotic rim. In two cases the zone adjacent to cancellous bone diminished by 1-1.5 mm during the first 2 years after surgery. There was a positive correlation between the maximal width of the zone adjacent to cancellous bone and the volume of cement fillings. Our findings indicate that the radiolucent zone surrounding bone cement is caused by thermal necrosis.