Experimental study on postlaminectomy deterioration of cervical spondylotic myelopathy. Influences of intradural surgery and persistent spinal block.

This experiment studied the postoperative changes around the dural tube at the site of cervical laminectomy, which are influenced by intradural operative procedures and the flow of cerebrospinal fluid. Forty dogs were divided into four groups in accordance with the type of decompressive procedure done, and three types of dural surgery were added: none (laminectomy alone), dura resection, or arachnoid resection. While the scar tissue did not adhere to the spinal cord after arachnoid resection in normal dogs, adhesion of scar to spinal cord was seen to a small extent after arachnoid resection with sufficient posterior decompression in dogs whose spinal cord was compressed anteriorly by a screw through the vertebral body. In the cases with insufficient posterior decompression adherence was observed much more extensively.