Effects of electromagnetic field (1.8/0.9 GHz) exposure on growth plate in growing rats.

The purpose of this study was to determine the effects of whole-body electromagnetic field (EMF) exposure on growth plates in growing male rats. Two groups of rats were exposed to either 900 MHz EMF or 1800 MHz EMF 2 h/day for 90 days. Sham control rats were kept under similar conditions without exposure to the EMF. The rats in the EMF group experienced a more rapid weight gain and increase in length (p < 0.05). Calcium, growth hormone, estradiol and testosterone levels in the EMF groups were higher (p < 0.05). The Safranin O staining density of femoral growth plate was lowest in the reserve zone of rats exposed to 1800 MHz and was increased in the proliferative zone of the control group (p < 0.05). The trabecular zone was thinnest among all zones and the reserve and proliferative zones were thicker (p < 0.05) than other zones in 1800 MHz group.In conclusion, 1800 MHz and 900 MHz EMF may cause prolong the growth phase in growing rats.

Management of femoral fractures in dogs with unilateral semicircular external skeletal fixators.

OBJECTIVE: To report use of semicircular external skeletal fixators (ESF) for management of femoral fractures in dogs. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs (n=16) with femoral fractures (n=18). METHODS: A semicircular ESF system composed of 6-hole 45° or 5-hole 40° carbon-fiber arches, 6 mm threaded rods, half pin fixation bolts, 6 mm nuts, and negative profile end-threaded half pins were used for open repair of femoral fractures. ESF configuration, complications, limb use, fixator removal time, and functional outcomes were evaluated. Outcome was graded as excellent, good, fair, or poor. RESULTS: Seventeen fractures with sufficient follow-up healed. Eight dogs started using the limb immediately after waking up from anesthesia whereas initial limb use was 1-4 days after repair in the other dogs. Time to fixator removal ranged from 28 to 63 days (mean, 38 days). Functional outcome was excellent in 13 cases, good in 4, and poor in 1 nonunion. CONCLUSION: Semicircular ESF combined with open surgical reduction can be used to successfully repair metaphyseal and diaphyseal femoral fractures in young growing dogs.