Contraindications
- •
Laminectomy can be used to treat patients with radiculopathy. However, MRI findings of herniated disk fragments will prompt consideration of additional diskectomy and foraminotomy to further decompress the affected nerve roots
- •
Relatively contraindicated in patients with congenital or acquired pars defects—fusion is required to prevent dynamic instability and spondylolisthesis
Planning and positioning
- •
Preoperative evaluation includes a thorough neurologic history and examination with assessment of strength. A sensory examination should be conducted to rule out any dermatomal distribution of loss. Routine plain lateral and flexion and extension lumbar spine films can show dynamic instability that would be better treated with lumbar fusion rather than laminectomy alone. Magnetic resonance imaging (MRI) without contrast enhancement of the lumbar spine can show focal neural foraminal stenosis that may be better addressed with focused diskectomy and foraminotomy.
- •
After being placed prone, the patient is given a dose of preoperative antibiotics before the skin incision. Antibiotics and an intramuscular dose of ketorolac (Toradol) can be instilled at the end of the case.
FIGURE 70-1:
The patient is positioned prone on chest rolls on a Wilson frame to hold the spine in extension.
Procedure
Skin Incision
Fascial and Subfascial Dissection
- •
Bovie electrocautery can be used for subcutaneous dissection and for achieving hemostasis. The thoracolumbar fascia is identified after dissection through the subcutaneous fat. A dry sponge raked along the fascia identifies the white tissue easily, and a periosteal elevator can be used to dissect off the subcutaneous fat from the fascia beneath. After placing a self-retaining retractor, such as a Gelpi retractor, palpation to find the midline can be done.
Subperiosteal Dissection
- •
Bovie electrocautery on cut function can be used to cut through the fascia. (For microdiskectomy, a paramedian fascial incision ensures the midline ligamentous structures are not damaged by dissection.) After minimal one-sided exposure is completed rapidly, a localizing film should be obtained to assess the correct level.
- •
Subperiosteal dissection can also be done rapidly with an open dry sponge raked ventrally and laterally along the spinous process and lamina with a large periosteal dissector, such as a Cobb elevator. This dissection can be done very rapidly and in the case of in situ lumbar fusion can be carried out to the lateral gutters to rest atop the transverse processes of the lumbar vertebrae.
Beginning of Laminectomy
