[An experimental study on preserving the intervertebral discs, in dog--prior to disc allografting].

Disc grafting is a new surgical procedure that may be suitable for preserving mobility of the spine. This experimental study was designed to determine a method of favorably preserving a disc prior to allografting. The lumber vertebrae of adult mongrel dogs were aseptically excised, regarded as the vertebral body-disc unit, and preserved at -80 degrees C, or at 4 degrees C. In the preservation at 4 degrees C, UW solution, Euro-Collins solution, EP-II solution, Ham's F-12, or physiological saline solution was used for preservation. Isotopes were used for determining the activities of the disc cells. In the preservation at -80 degrees C, it was difficult to maintain the activity regardless of the preservation period. There was no difference among these preservative solutions in the preservation at 4 degrees C on the nucleus pulposus, but the 2-day preservation in UW solution provided the best results in terms of the annulus fibrosus. Based on the results of these experiments, at -80 degrees C it was difficult to maintain the activity of disc cells while at 4 degrees C the UW solution was the most effective for preserving the anulus fibrosus. However the period of preservation was very short, and a new method to enable longer periods of preservation should be developed.