Laminectomy

Laminectomy
Intervention
Upper view of a human vertebra, showing the lamina
ICD-9-CM	03.09
MeSH	D007796
MedlinePlus	007389
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A laminectomy is a surgical procedure that removes a portion of the vertebral bone called the lamina. The back muscles are pushed aside rather than cut and the parts of the vertebra adjacent to the lamina are left intact. Recovery typically occurs within a few days.

The lamina is a posterior arch of the vertebral bone lying between the spinous process (which juts out in the middle) and the more lateral pedicles and the transverse processes of each vertebra. The pair of laminae, along with the spinous process, make up the posterior wall of the bony spinal canal. Although the literal meaning of laminectomy is 'excision of the lamina', a conventional laminectomy in neurosurgery and orthopedics involves excision of the posterior spinal ligament and some or all of the spinous process. Removal of these structures with an open technique requires disconnecting the many muscles of the back attached to them. A laminectomy performed as a minimal spinal surgery procedure is a tissue-preserving surgery that leaves more of the muscle intact and spares the spinal process. Another procedure, called the laminotomy, is the removal of a mid-portion of one lamina and may be done either with a conventional open technique or in a minimalistic fashion with the use of tubular retractors and endoscopes.

A lamina is rarely, if ever, removed because the lamina itself is diseased. Instead, removal is done to break the continuity of the rigid ring of the spinal canal to allow the soft tissues within the canal to: 1) expand (decompress); 2) change the contour of the vertebral column; or 3) permit access to deeper tissue inside the spinal canal. A laminectomy is also the name of a spinal operation that conventionally includes the removal of one or both lamina, as well as other posterior supporting structures of the vertebral column, including ligaments and additional bone. The actual bone removal may be carried out with a variety of surgical tools, including drills, rongeurs and lasers.

The success rate of a laminectomy depends on the specific reason for the operation, as well as proper patient selection and the surgeon's technical ability. The first laminectomy was performed in 1887 by Victor Alexander Haden Horsley, a professor of surgery at University College London. A laminectomy can treat severe spinal stenosis by relieving pressure on the spinal cord or nerve roots, provide access to a tumor or other mass lying in or around the spinal cord, or help in tailoring the contour of the vertebral column to correct a spinal deformity such as kyphosis. A common type of laminectomy is performed to permit the removal or reshaping of a spinal disc as part of a lumbar discectomy. This is a treatment for a herniated, bulging, or degenerated disc.