TO DATE little has been written about recurrent herniated disks. Most of the articles written on the subject have dealt with recurrence of the intervertebral disk at the site of former operation or at an interspace above or below the one previously explored.
In a follow-up study of Dandy's group of 843 cases, Lenhard1 examined 147 patients. Of those examined, 20 patients had been subjected to multiple operations supposedly because of recurrent herniation. Twenty-five of these had concealed disks. The exact site of recurrences was not given. In a series of 1,217 patients operated on at the Mayo Clinic, Love2 found 47 with recurrent protruded disks. He stated that "when a patient has recurrent nerve root symptoms after removal of a protruded intervertebral disk, usually there is further protrusion of fibrocartilage from the same interspace; rarely, another disk is involved." He expressed the opinion that there is no