Lumbar Laminectomy

Lumbar Laminectomy is a surgical procedure of the spine performed to relieve pressure on nerves exiting the spinal canal thereby eliminating pain. To learn more about Lumbar Laminectomy, let us first learn about normal spine anatomy.

Normal Spine Anatomy

The spine, also called the back bone, is designed to give us stability, smooth movement, as well as providing a corridor of protection for the delicate spinal cord. It is made up of bony segments called vertebrae and fibrous tissue called intervertebral discs. The vertebrae and discs form a column from your head to your pelvis providing symmetry and support to the body. The spine can be divided into 4 parts. The uppermost is the cervical region, consisting of 7 small vertebrae that form the neck. As we move down the body, the next 12 vertebrae make up the thoracic region or mid back from which the ribs are hinged. The 5 lumbar vertebrae are the largest of the mobile vertebrae and supports 2/3 of the body’s weight. The lowest region of the spine is the sacrum and coccyx. The sacrum is a triangular plate made up of 5 fused vertebral segments while the 4 coccyxes terminate the bony spine.

Vertebra

A single vertebra is made up of two parts; the front portion is called the body, cylindrical in shape, and is strong and stable. The back portion of the vertebra is referred to as the vertebral or neural arch and is made up of many parts.

The strong 2 pedicles join the vertebral arch to the front body. The laminae form the arch itself while the transverse process spread out from the side of the pedicles like wings to help anchor the vertebral arch to surrounding muscle. The spinous process forms a steeple at the apex of the laminae, and is the part of our spine that is felt directly under the skin.

Laminae

The laminae of the vertebra can be described as a pair of flat arched bones that form a component of the vertebral arch.

Spinal Canal

This canal is formed by the placement of single vertebral foramina, one on top of the other, to form a canal. The purpose of the canal is to create a bony casing from the head to the lower back through which the spinal cord passes.

Pars Inter Articularis

Known as the Pars, it is the part of the vertebral arch where the pedicle, transverse process, and articular process transect.

Intervertebral Disc

The intervertebral disc sits between the weight bearing vertebral bodies, servicing the spine as shock absorbers. The disc has fibrous outer rings called the annulus fibrosus with a watery jelly filled nucleus called the Nucleus Pulposis.

Spinal Cord

The spinal cord is the means by which the nervous system communicates the electrical signals between the brain and the body. It begins at the brain stem and is held within the spinal canal until it reaches the beginning of the lumbar vertebrae. At L1 the spinal cord resolves down to a grouping of nerves that supply the lower body.

Facet Joint

Facets joints are the paired articular processes of the vertebral arch. These synovial joints give the spine it’s flexibility by sliding on the articular processes of the vertebrae below.

Indications for Lumbar Laminectomy include:

• Spinal Stenosis: A condition caused by narrowing of the spinal canal due to excess bone growth or tissue such as cartilage. This narrowing can cause pressure to occur on the spinal nerves leading to pain, numbness, and weakness in the legs, feet, and buttocks.
• Herniated Intervertebral Disc: A condition caused by a tear in a disc causing the disc contents to bulge outside of the disc. Symptoms related to herniated discs in the lumbar region include sharp, continuous back pain, weakness in the legs, and some loss of sensation to the leg and foot.
• Cauda Equine Syndrome: A very serious compression disorder of the spine. The Cauda Equine is an area at the base of the spinal cord where the nerve roots of all spinal nerves are located. Compression in this area can cause loss of all nerve function below the site of compression and loss of bowel and bladder control. This condition is a surgical emergency requiring immediate decompression of the spinal nerves.
• Degenerative Spondylolisthesis: This condition is degeneration (wear and tear) of the vertebral components, usually occurring after age 50, causing slippage of a vertebra onto another, leading to spinal stenosis, a narrowing of the spinal canal.
• Metastatic Tumors: tumors near the spine can cause compression of the spinal nerves.

Diagnosis

Evaluating the source of back pain is critical in determining your options for relief of the pain and the location of where to perform surgery.

Dr Hsu will perform the following:

• Medical History
• Physical Examination

Diagnostic Studies may include:

• X-rays: a form of electromagnetic radiation that is used to take pictures of bones.
• MRI: magnetic and radio waves are used to create a computer image of soft tissue such as nerves and ligaments.
• CT Scan: a type of medical imaging that creates 3D images from multiple x-rays
• Myelogram: a test which is done by injecting a contrast medium into the affected area of the spine followed by several x-rays of the area.

Surgery Introduction

Lumbar Laminectomy, one of the most common back operations performed, is a surgical procedure to alleviate severe pain and disability resulting from the compression of spinal nerves. The ultimate goal of the surgery is to alleviate the patient’s pain by removing the cause of the compression on the spinal nerves by widening the spinal canal.

Causes of spinal compression can be:

• Bulging or herniated discs
• Bone Spurs (osteophytes)
• Arthritis
• Disc Fragments
• Tumors
• Scar Tissue

Lumbar Laminectomy surgery is usually recommended for patients whose symptoms have not been relieved by other treatments such as rest, medication, Physical Therapy, and pain blocking injections.

Some patients may be candidates for a minimally invasive approach to surgery. However, most Laminectomies are performed through a larger, open incision.

Surgical Procedure

• The surgery is performed under sterile conditions in the operating room with the patient under general or spinal anesthesia and lying or kneeling face down in a specialized operating frame.
• Dr Hsu will make an incision in the middle of the lower back area over the affected vertebrae down to the spinous process.
• Dr Hsu then cuts the muscles around the lamina and facet joints, peeling them back and holding them in place with special instruments called retractors.
• The lamina and transverse process of the affected vertebrae are then removed or trimmed exposing the ligamentum flavum, an elastic ligament that helps connect two vertebrae.
• An opening is cut in the ligamentum flavum to gain access to the nerves in the spinal canal, allowing the surgeon to identify the cause of compression.
• The nerve root is then gently pushed aside so Dr Hsu can remove any structures that are pressing on the nerves, such as a protruding disc or bone spurs.
• Dr Hsu may also enlarge the neural foramina, the small opening between the vertebrae where the spinal nerves exit the spinal canal, to further relieve pressure on the nerves.
• If necessary, a spinal fusion may be performed to stabilise the spine, especially if large parts of bone were removed or multiple levels were operated on.
• Dr Hsu will then suture the muscle and soft tissues to close the incision.

Postoperative Care

• You will be taught how to use proper body mechanics to turn in bed, reposition, and stand up, sit, and walk while the incision is healing.
• You will normally stay in the hospital 3-5 days, less for minimally invasive surgery.
• You will be given pain medication to make you comfortable and you may have a PCA machine: a patient controlled device to administer pain medication.
• You will probably have a urinary catheter.
• A postoperative rehabilitation program may be prescribed by Dr Hsu
• You will be encouraged to walk as much as tolerated and avoid prolonged sitting.
• Avoid pulling, pushing, or lifting.
• Keep the incision area clean and dry and report any signs or symptoms of infection to Dr Hsu Nurse such as redness, swelling, increased pain, excess drainage, odorous drainage, fever, or chills.

Risks and complications

• As with any major surgery there are potential risks involved. The decision to proceed with the surgery is made because the advantages of surgery outweigh the potential disadvantages.
• It is important that you are informed of these risks before the surgery takes place.

Complications can be medical (general) or specific to spinal surgery.

Medical complications include those of the anesthetic and your general well being. Almost any medical condition can occur so this list is not complete. Complications include

• Allergic reactions to medications
• Blood loss requiring transfusion with its low risk of disease transmission
• Heart attacks, strokes, kidney failure, pneumonia, bladder infections
• Complications from nerve blocks such as infection or nerve damage
• Serious medical problems can lead to ongoing health concerns, prolonged hospitalisation, or rarely death.

Specific complications of Lumbar Laminectomy include:

• Post-Laminectomy Syndrome: symptoms include chronic back pain and spinal instability.
• Infection at the surgical site
• Wound Dehiscence: when the incision line splits open.
• Hematoma Formation: a localised, collection of blood
• Dural sac tears with leakage of cerebrospinal fluid
• Nerve root damage
• Spinal Instability
• Bowel or bladder incontinence