Define laminotomy.

Laminotomy refers specifically to the surgical procedure in which a portion of the lamina of a vertebra is removed or divided. The lamina is the part of the vertebral arch that forms the roof of the spinal canal. This procedure is often performed to relieve pressure on the spinal cord or the nerve roots, providing access to the spinal canal for additional treatments, such as decompression of herniated discs.

The definition aligns directly with the surgical goal of laminotomy, which is to allow access while preserving as much of the structural integrity of the vertebra as possible. The other options describe different surgical procedures or conditions that do not accurately represent the essence of what a laminotomy entails.