As pictured,the lamina is a posterior arch of the vertebral bone laying between the spinous process, which juts out in the midline, and the more lateral of each vertebra. The pair of lamina, 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, the operation called conventional laminectomy, which is a standard spine procedure in neurosurgery and orthopedics, removes the lamina, spinous process and overlying connective tissues and ligaments,cutting through the muscles that overlie these structures. Minimal surgery laminectomy is a tissue preserving surgery that leaves the muscles intact, spares the spinal process and takes only one or both lamina. Laminotomy is removal of a mid-portion of one lamina and may be done either with a conventional open technique, or in a minimal fashion with the use of tubular retractors and endoscopes.
A lamina is rarely, if ever, removed because it itself is diseased. Instead, removal is done to: (1) break the continuity of the rigid ring of the spinal canal to allow the soft tissues within the canal to expand (decompression), or (2) as one step in changing the contour of the vertebral column, or (3) in order to allow the surgeon access to deeper tissues inside the spinal canal. 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.
Conventional open laminectomy often involves excision of the posterior spinal ligament, and some or all of the spinous process, and facet joint. Removal of these structures, in the open technique, requires cutting the many muscles of the back which attach to them. Laminectomy performed as a minimal spinal surgery procedure, however, allows the bellies of muscles to be pushed aside instead of transected, and generally involves less bone removal than the open procedure.
The success rate of laminectomy depends on the specific reason for the operation, as well as proper patient selection and technical ability of the surgeon. Indications for laminectomy include (1) treatment of severe spinal stenosis by relieving pressure on the spinal cord or nerve roots, (2) access to a tumor or other mass lying in or around the spinal cord, or (3) a step in tailoring the contour of the vertebral column to correct a spinal deformity such as kyphosis . The actual bone removal may be carried out with a variety of surgical tools, including drills, rongeurs, and laser.
The recovery period after laminectomy depends on the specific operative technique; minimally invasive procedures having a significantly shorter recovery period than open surgery. Removal of substantial amounts of bone and tissue may require additional procedures to stabilize the spine, such as fusion procedures, and spinal fusion generally requires a much longer recovery period than simple laminectomy.
Most commonly, laminectomy is performed to treat spinal stenosis.
Spinal stenosis is the single most common diagnosis leading to any type of spine surgery, and laminectomy is a basic part of its surgical treatment. The lamina of the vertebra is removed or trimmed to widen the spinal canal and create more space for the spinal nerves and thecal sac. Surgical treatment that includes laminectomy is the most effective remedy for severe spinal stenosis, however most cases of spinal stenosis are not severe and do not require surgery. When the disabling symptoms of spinal stenosis are primarily neurogenic claudication, and the laminectomy is done without spinal fusion, there is generally a very rapid recovery with excellent long term relief. However, if the spinal column is unstable, and fusion is required, there is a recovery period of months to more than a year, and relief of symptoms is less likely.
'''Results of the surgical treatment
In most known cases of lumbar and thoracic laminectomies patients tend to recur pain/spinal stenosis for a period of 1 / 1.5 years and tend to recover very slowly. According to a W.H.O. census in 2001, most patients who had undergone lumbar laminectomy recovered normal functioning a year after their operation.