Safety of lumbar spine radiofrequency procedures in patients who have posterior spinal hardware

Objective. The purpose of this study was to determine whether the energy generated by an active radiofrequency (RF) cannula adjacent to lumbar spine hardware could result in heating of the hardware. Design. Prospective study. Setting. Tertiary care medical center. Subjects. Six patients with lumbar facet joint pain at the level adjacent to lumbar spine fusion hardware were studied. Methods. A total of 10 lumbar medial branch nerve radiofrequency lesion procedures were performed on six patients. A temperature probe was placed on the fusion hardware to continuously monitor the temperature of the hardware throughout the RF procedure. Results. The temperature of the fusion hardware increased in six of the 10 RF lesion procedures. During two of the procedures, the temperature rose rapidly to 42°C, at which time the procedure was ceased at that level. Conclusion. This study demonstrated that radiofrequency lesioning to treat symptomatic facet joint pain in patients who have adjacent posterior lumbar fusion hardware may result in heat energy being transferred to the adjacent hardware. This may increase the risk of injury to the patient. Monitoring for a temperature increase is easily accomplished by inserting a temperature probe onto the surface of the hardware.