The surgical technique for removal of ruptured lumbar intervertebral disc -has changed very little since it was introduced by Mixter and Barr in 1934.
The technique of the interlaminar operation used by most neurosurgeons was used successfully in early cases to relieve the sciatica, but many patients were unable to return to heavy work because of low back pain.
Cloward described a different surgical technique for removal of a ruptured- lumbar intervertebral disc.The operation utilizes a transverse skin incision and a wide bilateral stlipping and retraction of fascia and muscles. The ligamentum flavum is not., removed but detached and reflected medially in a flap. Only the bone margins of the adjacent facets are´ removed. A complete laminectomy is never done except for spondylolisthesis when the separate neural´ arch is disarticulated and removed. Using a "Vertebral Spreader", an interlaminar, exposure is developed two to three times larger than that obtained by the "standard" technique.
The advantages are obvious:
1. Both operations were done through a single transverse incision.
A wider lateral exposure for the skin wound, being made parallel to the lumbar operation was possible and. the normal skin lines, heals better with less scar.
2. The entire ligament is preserved, by separating its attachments from the lamina and reflecting in a flap, a larger opening into the spinal canal is obtained and the replaced flap protects the dura and prevents scarring.
3. Cloward recommends the use of a narrow, sharp chisel and hammer, but we used the spinal rongeurs including the Kerrison punch to remove part of the laminal edge. We leave the articular facets of the lumbar disc surgery because the articular facets are considered important major elements in the articulation of the vertebral joints, and as an essential bony surface to be used in posterior spinal fusion operation.
4. The routine use of intrathecal cortisone after lumbar disc operation has not been used in our cases because of increased pressure of the cerebrospinal fluid in modified prone position of the patient.
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