Our analysis suggested that in patients operated on for primary lumbosacral disc protrusion, a more lasting postoperative result could be anticipated if disc removal and fusion were carried out simultaneously, but statistical analysis did not substantiate this impression. Patients who experienced a recurrence after removal of the protruded fifth lumbar intervertebral disc without fusion usually required fusion later.

At the fourth lumbar level, on the other hand, the addition of a fusion operation at the time of the primary operation did not appear to increase the chances for a good postoperative result.

Disc protrusions at the third lumbar level usually were removed without fusion because the likelihood of pseudarthrosis increased proportionately with the length of the bone graft applied.

With disc protrusions occurring simultaneously at the lumbosacral interspace and the interspace above, a fusion operation performed at the same time as removal of the two discs appeared to offer a more lasting result.

Since our patients were selected for operation by an orthopaedic surgeon as well as a neurosurgeon, a valid objection could be made on the basis of selection of patients. Although the results in all categories are encouraging, it is disappointing that they are not better. Pain in the lower part of the back and in the leg is not always due to degenerative disc disease and careful selection of patients appears essential to achieve better long-term postoperative results.