Each vertebra in the back contains two laminae, which are bony segments that serve as the base of the vertebra.

Heavy lifting, trauma and degeneration can causes these segments to slip out of position, or herniate, and pinch sensitive nerves. This can lead to pain, weakness, and numbness in the back and legs.

During hemilaminectomy, small portions of the lamina are removed to relieve pain and create more space in the spinal column to take pressure off the nerve tissue.