Posterior Lumbar Decompression

OVERVIEW

Posterior Lumbar Decompression is a surgical procedure that utilizes a posterior approach to relieve pressure from inside the spinal canal in the lower back. Pressure build-up caused by spinal stenosis (narrowing of the spinal canal) can occur at multiple levels of the spine. To obtain access to the spine, an incision is made in the lower back. It is usually 2 to 4 inches long, depending on the number of levels being decompressed.

Posterior Lumbar Decompression is achieved through a surgical technique known as laminectomy. A complete laminectomy consists in the removal of the lamina portion of bone. Once the lamina is removed, the spinal canal is open. This allows for additional ligaments or a herniated disc to then be removed to ‘decompress’ the neural elements completely.

Additionally, a foraminotomy, which consists in the removal of bone spurs close to spinal opening (foramen) where the nerve roots come out of the central canal, may be performed. The foraminotomy allows the previously pinched nerve root to return to its normal size, decreasing irritation.

WHY POSTERIOR LUMBAR DECOMPRESSION?

Posterior Lumbar Decompression is commonly performed to relieve the pressure from the spinal canal and the cauda equina (lower part of the spinal cord) and adjacent nerve roots caused by spinal stenosis. This pressure usually causes pain, weakness or numbness that can radiate into the buttocks and/or down the legs.

                                                                                                                                   

SURGICAL PROCEDURE -STEP BY STEP-

INCISION MADE

                                                                                                                                   

A 2-4 inch incision is made in the lower back. (The size of the incision varies depending on the number of vertebrae affected.)

REMOVAL OF THE SPINOUS PROCESSES

After the incision, the spine is exposed and bone and ligaments causing pressure on the spinal canal and associated nerve roots can be removed. The first bony complexes to be removed are the spinous processes, which are portions of the vertebrae that protrude furthest from the back of the spine.

*you can actually feel the spinous process by touching the middle portion of your lower back*                                                                                                                                    
                                                                                                                                   

REMOVAL OF LAMINA

Following the removal of the spinous processes, the spinal canal is entered, and the lamina is removed. The removal of the lamina is referred to as ‘laminectomy’. This procedure takes the pressure of the nerves and prevent further pinching of the nerves inside the spinal canal and through the nerve tunnels.

                                                                                                                                   

ADDITIONAL DECOMPRESSION OF THE ‘LATERAL RECESS’

This additional step is performed only in patients with compressed nerve root(s) who can benefit from an additional removal of bone fragments adjacent to the nerve root opening (foramen). This area is called the “lateral recess”. After the lamina is removed, the nerve roots branching off the decompressed central canal, are gently retracted.

If the nerve roots appear to be pinched towards the lateral part of the canal, the residual bone fragments adjacent to the foramen are removed to free the exiting nerve roots. This particular procedure is referred as lateral recess decompression and foraminotomy, or opening of the nerve tunnel outside of the spinal canal.

                                                                                                                                   

PRESSURE IS RELIEVED

Once the lamina and potential bone and ligament fragments from around the foramen are removed the surgical procedure is considered complete. At this point both the central spinal canal and the nerve root(s) are no longer subject to presure and irritation and the spinal canal is clear.

                                                                                                                                                                  

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