ABSTRACT
The sciatic nerves of rabbit were frozen with different temperatures(-20℃,-60℃, -- 100℃, -140℃ and 180℃).The morphology and function of the frozen nerves were examined with light microscopy (HE stain and histochemical thiocholism method), electron microscopy, and short latency sematesthelic evoked potentials(SSEP), sensory conduction velocity(SCV), electromyo-gram(EMG) at various time intervals after freezing. It was showed that there were no changes in morphology and function of nerves after being frozen at -20C. The nerve fibers showed signs of frozen degeneration and lost their conduction function at -60℃. However, the nerves could recover in this group. About one half of the nerve fibres frozen with -100℃ showed Wallerian degeneration, and the time of repair was delayed. But still the regeneration of nerves was complete. Necrosis of nerve fibers occurred immediately after freezing with -140℃ and-180℃. There were destruction of the basement membrane and proliferation of collagen fibers. The results explained the mechanism of cryoanalgesia clinically. We believe that the temperatures lower than -140℃ are optimal for cryoanalgesia.
ABSTRACT
Cryotherapy as applied to deep lying tissues is a new technique in orthopedics. In this paper, 120cases were reported. Using "Liquid-air double-layer cryo-needle", lowback pain, the painful heel andtennis elbow were treated by freezing the dorsal ramus of the spinal nerve, the calcaneal nerve andthe terminal branches of the radial nerve in elbow. The results were good. The authors believed that cryotherapy was simple, safe and effective, and no side-efffects and complications were observed.