Experimental study of intervertebral disc allografting in the dog.

STUDY DESIGN

An investigation of the use of intervertebral disc allografting as a potential alternative to intervertebral fusion was performed. In 13 adult mongrel dogs, intervertebral disc units cryopreserved after slow freezing were grafted.

OBJECTIVES

To evaluate the morphologic and biosynthetic damage caused by cryopreserving the canine intervertebral disc before allografting.

SUMMARY OF BACKGROUND DATA

Cryopreservation did not alter the normal histologic appearance. The metabolic activity, measured by 35S-sulfate incorporation, was observed to be 44% of the fresh control.

METHODS

Transplanted intervertebral discs were examined histologically and radiographically at 12, 24, and 48 weeks after surgery.

RESULTS

The allografted disc had preserved anular and nuclear architecture with moderate loss of chondrocytes 12 weeks after grafting. However, the intervertebral disc showed evidence of progressive disc degeneration 1 year after transplantation.

CONCLUSIONS

More investigation of storage methods is needed to enhance the viability of the intervertebral disc for successful intervertebral disc allografting.