A lumbar laminectomy removes the lamina, a bone in the spinal canal, and ligaments attached to the spine, according to the Columbia University Medical Center. The surgeon also shaves down the arthritic facet joints to allow more room for the spinal nerves.
The removal of the lamina bone becomes medically necessary when the spinal nerves become compressed due to enlargement of bone spurs, ligaments and joints, explains the Columbia University Medical Center. In cases like these, the spinal nerves need more decompression than a simpler surgery achieves. Sometimes, surgeons refer to this surgery and removal of bone and ligaments as “unroofing” the spinal canal.