Abstract
To determine effective ways of repairing the disc after nucleotomy, a series of canine experiment were performed. Under intravenous pentobarbital anesthesia, the lumbar intervertebral discs were approached anteriorly and nucleotomy was performed. The animals were divided into five groups : the first group underwent simple discectomy without replacement as a sham surgery. The second group underwent insertion of an autologous nucleus pulposus taken from an other disc. The third group underwent injection of fibrin tissue adhesive sealant. The fourth group underwent insertion of autologous synovium taken from the right knee joint and the fifth group underwent injection of sodium hyaluronate. In each group except after the first group, the anterior defect was repaired after the annulus fibrosus was removed from the other disc and sealed with fibrin tissue adhesive. Animals were sacrificed at intervals up to 12 weeks following the procedure, and histological observations were made. Fifty-two discs of 18 mongrel dogs were studied.
In the first group, degeneration of the disc appeared to have progressed further. In the other groups, disc degeneration appeared to have been arrested to some extent, but regeneration of the disc was not apparent. However, there was no difference in histological findings among groups two to five. The initial injury to the disc by the nucleotomy may have been too extensive to be repaired by regenerated chondrocytes although some fibrous cartilaginous tissue reappeared in the surrounding tissue. In the fifth group in which sodium hyaluronate had been injected, the end plate was destroyed by proliferative chondrocytes.
