Percutaneous radiofrequency ablation:: relationship between different probe types and procedure time on length and extent of osteonecrosis in dog long bones

Purpose We have been using radiofrequency ablation for the percutaneous treatment of osteoid osteoma since 2001. Frequently, lesions are located near the joint surface, involve the vertebral body or are close to major nerves. We seek to determine whether radiofrequency ablation (RFA) can be used safely in these cases. Materials and methods A total of 65 lesions were induced in 4 dogs. Each dog underwent RFA on the diaphysis of long bones, as well as femoral and humeral heads. Four different sessions were carried out by using 1- and 2-cm probes with or without a cool-tip system and by varying the timing of the procedure. Plain film, CT, and MRI were obtained. All bone samples were examined histologically. Results The dogs' activity after the procedure was normal. No pathologic fractures occurred despite unrestricted activity of the animals. Cortical bone was always respected; therefore, articular cartilage has not been damaged. Radiological findings were characteristic. There were no significant differences in lesion size, probe type, and the duration of the procedure. The mean lesion diameter perpendicular to the electrode was 18.5 mm. Conclusions Our study confirms the insulative effect of cortical bone. RFA can be safely performed close to the joint surface without damaging the cartilage.