Effects of monopolar radiofrequency heating on intradiscal pressure in sheep.
BACKGROUND
No previous study has assessed the effect of monopolar radiofrequency (RF) heating on intradiscal pressure.


OBJECTIVE
To determine the decrease in lumbar intradiscal pressure after monopolar RF heating.


METHODS
Intradiscal pressure was measured in sheep lumbar discs treated with monopolar RF heating.


METHODS
Two monopolar RF heat treatments at 90 degrees C were applied for 2 minutes each to lumbar intervertebral discs of sheep. Intradiscal pressure was measured in live sheep at 0, 7, 14, 21, and 28 days posttreatment. Pressure measurements were taken with a microtip pressure transducer. Electrodes were inserted but not activated in separate discs as a sham control. In vitro sheep spine of different age groups, loading conditions, and electrode orientations were similarly heat treated and intradiscal pressures were measured.


RESULTS
Intradiscal pressure was significantly reduced 1 week after monopolar RF heating and remained stable through the 4-week observation period. The RF electrode orientation, the age, and the type of disc loading have significant effects on the amount of initial intradiscal pressure reduction.


CONCLUSIONS
Monopolar RF heating can reduce intradiscal pressure in the lumbar spine of sheep.
Podhajsky
Ronald J
RJ
Valleylab, Tyco Healthcare, 5920 Longbow Drive, Boulder, CO 80301, USA. ron.podhajsky@tycohealthcare.com
Belous
Anna
A
Johnson
Kristin
K
Maul
Donald H
DH
Finch
Philip M
PM
D000818:Animals; D001416:Back Pain / Q000601:surgery; D004566:Electrodes; D006358:Hot Temperature / Q000627:therapeutic use*; D007403:Intervertebral Disc / Q000528:radiation effects*; D008159:Lumbar Vertebrae / Q000601:surgery*; D000078702:Radiofrequency Therapy; D012756:Sheep; D013117:Spinal Cord Compression / Q000601:surgery