Treatment of Degenerative Disc Disease and Degenerative Spondylolisthesis of the Lumbar Spine - Surgical

Indications for immediate surgery would include cauda equina syndrome or a major motor deficit in a lower extremity 4. Otherwise, a trial of non–operative treatment (m 6 weeks) should precede any surgical decision.

There is a wide menu of operative approaches that can be used to treat lumbar disc herniations 18, 19, 23. The so–called ''gold standard'' in the surgical management of lumbar disc herniations involves a limited laminotomy and partial disc excision 19, The other alterative is the micro–discectomy, which has many advocates who emphasize the major benefit is stronger illumination of the operative field and less morbidity because of the small incision 18, 23. Additional reported benefits are reduced scarring and more rapid recovery.

Those who do not use micro–discectomy cite an increased risk of missing pathology, operating at the wrong level, a higher rate of reoccurrence and an increased infection rate. At present there is little to prove added benefits or risks other than return to work and duration of hospital stay appear slightly shorter when compared to the standard technique 1S.

Regardless of technique it appears that removal of the obviously herniated fragments is all that is necessary. A more aggressive attempt at disc removal is fraught with increased risk of instability, which may lead lo the need for fusion within a short time after the index procedure. Curettage of the disc space should be avoided because of an increased risk of ''discitis'' reported in the literature 25.

At present there is no data in the literature to demonstrate any added benefit from the use of fusion as an adjunct in the prevention of future back pain or need for further surgery for lumbar disc herniation.

Indications for lumbar discectomy should include the clinical signs and symptoms that define the involved nerve roots verified by a positive MRI or CT/Myelogram imaging study.

The operative level should always be documented by an intraoperative radiograph. Following removal of a portion of the lamina the ligamentum flavum on the side of the disc herniation is removed. The nerve root and dura are carefully mobilized. The lateral recess is decompressed if needed and the nerve root is retracted medially exposing the disc herniation. The offending portion of the disc is removed with a pituitary rongeur. The disc space is carefully probed and any loose disc fragments are removed. Following disc removal the nerve root should be displaceable medially at least a centimeter to ensure that full decompression has been performed. A fat graft is placed over the nerve root and dural sac and the wound is irrigated and closed. When the operative approach is via micro–discectomy the principles are the same however a smaller incision (/2 – % inch) is used because of the advantage of illumination and magnification by the microscope.