Failure of the rabbit tibial growth plate to respond to the long-term application of a capacitively-coupled electrical field.
A continuous 5-V peak-to-peak, 60 kHz capacitively-coupled sine wave signal was applied to the proximal tibial growth plate in fifteen 9-week-old male New Zealand white rabbits for 6 weeks. A pair of flexible stainless steel "injectrodes" was held in place medially and laterally on the surface of the proximal hindlimb in each rabbit by means of tape wrappings. The electrodes were connected to a 9-V battery-operated power unit carried in a dorsal pouch in a body vest worn by each rabbit. Control animals wore the identical apparatus, only the power unit was inactive. Small Tantalum markers were inserted into the anteromedial aspect of the proximal tibial metaphysis 1 cm distal to the proximal tibial growth plate in all of the animals, control and experimental, 2 weeks prior to the onset of electrical stimulation. The distance between the proximal lateral tibial spine and the Tantalum marker, between the Tantalum marker and the apex of the distal tibial intercondylar notch, and between the proximal tibial spine and the distal notch was measured from roentgenograms made at the time of bone marker insertion, at the time of electrode application to the limb, and at the end of the stimulation period. Results indicate that there was no significant difference in tibial lengths between the stimulated and control groups. There was significantly less total body weight gain in both the experimental and control animals than that which occurred in paired normal animals during the same period of time. This failure to thrive may be responsible for the resultant lack of longitudinal growth stimulation of the capacitive coupling.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D001835:Body Weight; D004558:Electric Stimulation; D004560:Electricity; D004566:Electrodes; D006132:Growth Plate / Q000000981:diagnostic imaging / Q000254:growth & development*; D006614:Hindlimb; D008297:Male; D011817:Rabbits; D011859:Radiography; D013977:Tibia / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000254:growth & development*