The terms laminectomy and decompression are often used interchangeably, causing confusion about spinal surgery. Decompression refers to the overall objective of the surgery: relieving pressure on neural structures. Laminectomy, however, describes a specific surgical technique used to achieve that goal. Therefore, a laminectomy is a form of decompression, but decompression is a broader category that includes other procedures.
What Spinal Decompression Means
Spinal decompression is the surgical removal of material pressing against the spinal cord or branching nerve roots. This pressure, often caused by conditions like spinal stenosis, creates debilitating symptoms. The objective is to create more space within the spinal canal or the neural foramen, the narrow bony channels where the nerves reside.
The compression can be caused by bone spurs (osteophytes), thickened ligaments, a bulging or herniated intervertebral disc, or enlarged facet joints. When these tissues encroach upon the nerves, they cause radiculopathy, resulting in pain that radiates into the arms or legs (often called sciatica in the lower body). Successful decompression aims to alleviate this radiating pain, along with numbness, tingling, and muscle weakness.
Laminectomy as a Specific Decompression Procedure
A laminectomy is defined by the removal of the lamina, the bony arch forming the posterior roof of the spinal canal. This procedure is most commonly performed to treat spinal stenosis, which is the narrowing of the spinal canal.
Removing the lamina immediately creates more room in the central spinal canal, directly relieving pressure on the spinal cord and surrounding nerves. Surgeons often also remove the thickened ligamentum flavum, a dense ligament connecting the laminae that contributes to compression. This combined removal provides clear access to the compressed nerves and allows for the removal of any bone spurs or disc material. Laminectomy is typically performed when compression spans multiple spinal levels or when wide, central decompression is required.
The extent of removal varies. A complete laminectomy involves removing the entire bony arch, while a laminotomy removes only a small portion. The choice depends on the location and severity of the compression, aiming to remove the least amount of bone necessary for effective decompression. Removing the lamina may sometimes affect spinal stability, potentially necessitating an additional spinal fusion procedure to stabilize the vertebrae.
Decompression Methods That Are Not Laminectomy
The goal of decompression can be achieved through several other distinct surgical methods that do not involve complete lamina removal. The choice of procedure depends on the specific anatomical structure causing the nerve compression.
Microdiscectomy
A microdiscectomy focuses on removing a portion of a herniated intervertebral disc pressing on a nerve root. This highly targeted procedure often uses a microscope and involves removing soft disc material rather than bone.
Foraminotomy
A foraminotomy aims to enlarge the intervertebral foramen, the small bony opening where a nerve root exits the spinal column. The surgeon removes bone and other tissues surrounding the nerve exit to relieve localized compression.
Laminotomy
A laminotomy is a less extensive version of a laminectomy, removing only a small, targeted window of the lamina. This is often done just to access a herniated disc for a microdiscectomy.
All these procedures—microdiscectomy, foraminotomy, and laminotomy—are methods of spinal decompression because they relieve pressure on the neural elements, but they are technically distinct from a full laminectomy.