The lumbar shield: a preliminary report

Postoperative perineural adhesions between the lumbar nerve root and the partially removed intervertebral disc are thought to be a cause of failure of the standard operative procedure for the removal of a ruptured lumbar intervertebral disc. Attempts have been made to reduce postoperative perineural adhesions by the use of epidural muscle, fat, gelatin sponge, silicone, and steroids. The present communication introduces a new implantable silicone device, a lumbar shield, designed to: (a) provide a radiopaque marker on the dorsal perimeter of the excavated lumbar disc so that the presence or absence of a recurrent disc herniation can easily be determined on plain postoperative x-ray films, (b) provide ready access to the operative site in the event of a recurrent disc herniation, (c) prevent postoperative perineural adhesions between the lumbar dura and the nerve root and the partially removed intervertebral disc, and (d) prevent postoperative adhesions between the lumbar dura and the nerve root and the paraspinal muscles. Satisfactory results of lumbar disc surgery over the past 44 years have occurred in about 90% of routine patients. The value of the lumbar shield in 82 patients (59 routine and 23 workmen's compensation/medicolegal patients) followed for 6 months is described. A satisfactory result, i.e., relief of pain or the presence of occasional postoperative pain, occurred in 85% of routine patients at 1 month, 97% at 3 months, and 95% at 6 months.