A laminotomy is an orthopaedic neurosurgical procedure that removes part of the lamina of a vertebral arch in order to relieve pressure in the vertebral canal. A laminotomy is less invasive than conventional vertebral column surgery techniques, such as laminectomy because it leaves more ligaments and muscles attached to the spinous process intact and it requires removing less bone from the vertebra. As a result, laminotomies typically have a faster recovery time and result in fewer postoperative complications. Nevertheless, possible risks can occur during or after the procedure like infection, hematomas, and dural tears. Laminotomies are commonly performed as treatment for lumbar spinal stenosis and herniated disks. MRI and CT scans are often used pre- and post surgery to determine if the procedure was successful.

The spinal cord is housed in a bony hollow tube called the vertebral column. The vertebral column is composed of many ring-like bones called vertebra (plural: vertebrae) and it spans from the skull to the sacrum. Each vertebra has a hole in the center called the vertebral foramen through which the spinal cord traverses.

Laminae (singular: lamina) are the anatomical structures of primary importance in a laminotomy. Laminae are part of the vertebral arch which is the region of bone on the back side of each vertebra that forms a protective covering for the back side of the spinal cord.

The vertebral arch is composed of several anatomical features in addition to laminae that must be taken into account when performing a laminotomy. In the center of the vertebral arch is a bony projection called the spinous process. The spinous process is located on the posterior or back side of the vertebra and serves as the attachment point for ligaments and muscles which support and stabilize the vertebral column. Each vertebra has two lateral bony projections called the transverse processes which are located on either side of the vertebral arch. Transverse processes come into contact with the ribs and serve as attachment points for muscles and ligaments that stabilize the vertebral column. The lamina is the segment of bone that connects the spinous process to the transverse process. Each vertebra has two lamina, one on each side of the spinous process.

Different types of laminotomy are defined by the type of instrument used to visualize the procedure, what vertebra the procedure is performed on, and whether or not both lamina of a vertebra are operated on or just one.G

Common types of laminotomy:

These classifications of laminotomies can be combined to form the most descriptive name for the procedure possible. For example, an endoscopic unilateral lumbar laminotomy is the removal of bone from only one lamina of a lumbar vertebrae using an endoscope.

The procedure of a laminotomy remains largely the same regardless of the instrument used, or the level of vertebrae operated on. Laminotomies require general or spinal anesthesia and frequently require a hospital stay following the procedure—although the duration of the stay depends on the physical condition of the individual and their reason for having a laminotomy. A laminotomy takes about 70–85 minutes depending on the type of procedure used. Unilateral laminotomies typically require less time because bone is removed from only one lamina, whereas bilateral laminotomies usually take more time because bone is removed from both laminae. The level of the vertebrae that the laminotomy is performed on and what instrument is used produce no significant differences in the length of the procedure. Both unilateral and bilateral laminotomies are performed in a shorter time period compared to a conventional laminectomy which takes over 100 minutes on average.