Using x-ray guidance, two 2.5-cm incisions are made on either side of the lower back. The muscles are gradually dilated and tubular retractors inserted to allow access to the affected area of the lumbar spine.
The lamina is removed to allow visualization of the nerve roots. The disc material is removed from the spine and replaced with a bone graft and structural support from a cage made of bone, titanium, carbon-fiber, or a polymer, followed by rod and screw placement.
The tubular retractors are removed, allowing the dilated muscles to come back together, and the incisions are closed. This procedure typically takes about 3 to 3 1/2 hours to perform.