Artificial Lumbar Disc Replacement

The spine consists of a series of bones known as vertebrae, divided into distinct regions based on their curvature and function. The lumbar spine, located around and below the waist, comprises five large vertebrae. Each vertebra has a back portion that arches to form the lamina, which creates a roof-like cover over the opening at the back of each vertebra. This central opening forms the spinal canal, through which the spinal cord, nerves, and arteries pass, facilitating communication between the body and brain.

Between the vertebrae are intervertebral discs, constructed from strong connective tissue. The discs feature a tough outer layer called the annulus fibrosus and a gel-like center known as the nucleus pulposus. A healthy disc contains approximately 80% water. The discs, along with two small spinal facet joints, connect adjacent vertebrae, enabling movement and providing stability while acting as shock-absorbing cushions to protect the vertebrae.

Degenerative disc disease can affect any segment of the spine. Aging often leads to a loss of fluid in the discs, causing them to collapse or rupture, which decreases the space between the vertebrae. As discs deteriorate, the structural integrity of the vertebrae is compromised, potentially leading to conditions that place pressure on the spinal cord and nerves. While most pain symptoms are treated non-surgically, surgery may be recommended when the spine becomes unstable or when pain remains unmanageable through other treatments.

Intervertebral discs typically serve as cushions between vertebrae, but when a disc degenerates, it can become a source of pain. Abnormal bone growths known as bone spurs may form in the joints, encroaching on the spinal canal. A damaged disc can compress nerves, leading to chronic low back pain, along with burning, tingling, pressure, weakness, and numbness. These symptoms can radiate to the legs, known as sciatica.

In rare instances, loss of bowel and bladder control may signal a serious medical issue that requires immediate attention.

A physician can diagnose degenerative disc disease through a physical examination and imaging studies. The doctor will ask you to perform simple movements to evaluate your muscle strength, joint motion, and stability. A neurological examination of your arms and legs will help assess how the nerves are functioning, given their connection to the spine.

X-rays are performed to assess the condition of the vertebrae, and sometimes a myelogram—an injection of dye into the spinal column—enhances the X-ray images, revealing any pressure on the spinal cord or nerves caused by herniated discs, bone spurs, or tumors.

A computed tomography (CT) scan may also be conducted with or without a myelogram to examine the shape and size of the spinal canal and surrounding structures. A discogram, which involves injecting dye directly into a disc, can provide insight into the disc's internal structure and help determine if it is a pain source. Magnetic resonance imaging (MRI) offers the most detailed views of the discs, ligaments, spinal cord, nerve roots, and any tumors.

Most individuals with degenerative disc disease receive non-surgical treatment aimed at alleviating pain. These non-surgical approaches aim to relieve discomfort and restore functionality, although they do not correct structural deformities in the lumbar spine. Surgery is considered when non-surgical treatments have minimal or no effect on symptoms. Traditionally, spinal fusion surgery has been used to remove the degenerative disc and secure two or more vertebrae together, which can limit movement. An alternative option is artificial lumbar disc replacement.

The primary goal of artificial lumbar disc replacement is to relieve pain while preserving motion, minimizing further degeneration of the spine, and allowing for a quicker return to activities. Several types of artificial lumbar discs are available, and your surgeon will recommend the most suitable option for your situation.

The procedure is conducted as an inpatient surgery. The surgeon begins by making a small incision in the abdomen to access the front part of the lumbar spine, removing the damaged disc and any surrounding tissue. This allows for the vertebral space to be restored to its normal height, relieving pressure on the nerves.

The surgeon then inserts the artificial disc, which consists of two endplates and a sliding disc. The metal endplates are secured to the vertebrae, and the artificial disc is positioned between them. This phase of the surgery is performed under X-ray guidance (fluoroscopy) to ensure correct positioning of the artificial disc while maintaining proper spinal alignment.