Materials and Methods : l2 female 8~rbnth-old white New Zealand rabbits, weighing about 4-4.5 kg, were used. A retroperitoneal approach using a paravertebral incision was adopted. Using anumber-11 blade, a transverse stab incisian was made into the L3-4 and L5-6 disc through the antero-IateraJ annulus. At L3-4 level, complete annubtomy was performed and incomplete annulotany at the L5-6 level. In the complete annubtomy group, extrusion of the nucleus after annubtomy was confirmed. Gross arld histobgbaf findings, and lumbar x-rays and MRIs were analyzed. From simple x-rays, changes in disc heights were measured using NIH image software; degeneration grade was classified using MRI.
Results : The gross and histological findings showed progressive degenerative change in both groups, which were more severe in the complete annulotomy group. Simple radiographs showed a progressive decrease in the disc height and osteophyte formation in sever-al samples, whbh were mare severe in the complete annubtomy group. From the MRI findings, early degeneratne findings were identified 2 and 3 months after complete and incomplete annubtomy, respectively.
Cortdusion : In conclusion, the disc degenerative process, folbwing incomplete annubtomy, more resembled the natural course of disc degeneration than complete annubtomy.
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