Orthopaedic Spine Center
450 Broadway St. | MC6342
Redwood City, CA 94063
For Adult Patients: (650) 725-5905

Lumbar Spine Surgery

Below are some of the procedures offered by Dr. Cheng to treat lumbar spine conditions. Click the links below to learn more about the selected treatment:

Normal Spine

The spine in the lower (lumbar) back consists of the bony vertebrae, discs, nerves and other structures. The vertebrae, which stack up to create the spinal column, surround and protect the spinal cord and nerve roots. The end of the spinal cord (conus) is near the top of the lumbar spine. Below this, the nerve roots hang down in individual strands. These nerve roots, when viewed together, are somewhat similar in appearance to a horse’s tail, so the term used to describe them is cauda equina. The nerve roots travel out small bony windows (foramenae). The discs are located between each vertebra. Discs consist of a fibrous outer layer (annulus) surrounding a gelatinous center (nucleus). They allow motion between vertebrae, act as shock absorbers, and distribute the stress and strain placed on the spine.

Abnormal Spinal Conditions

Various conditions may be present, due to genetic or developmental problems, disease, trauma, or simply as a result of the normal aging process. These conditions may lead to pain, deformity, or a reduction in the capacity to carry out the usual activities of daily life. The most common condition is arthritis of the spinal joints. This can result in a narrowing of the room available around the nerve roots. This is called stenosis of the spinal canal due to bone spurs, cysts, or other degenerative changes. Another spinal condition that can pinch the nerve roots is slippage of one or more vertebrae on the vertebra below, called spondylolisthesis.

Most patients with stenosis have mild findings and do not experience serious symptoms. Some people, though, may require surgery if the nerve roots are severely irritated or the spinal column becomes unstable. There are rare circumstances in which patients require urgent surgery. These include cauda equina syndrome and/or progressive neurologic loss (increasing weakness). Symptoms of cauda equina syndrome include changes in bowel or bladder function, numbness or change in sensation in the area around the buttocks, genitalia, or thigh, and weakness and/or radiating numbness in the legs. People who develop symptoms of cauda equina syndrome should seek medical attention immediately.

As we age, the water and protein content of the body's cartilage and discs change. This change results in weaker, more fragile and thin cartilage. Because both the discs and the facet joints that connect the vertebrae are partly composed of cartilage, these areas are subject to wear and tear over time. The gradual deterioration of the discs is referred to as degenerative disc disease. This can be noted on x-ray tests or MRI scanning of the spine as a narrowing of the normal disc space between the adjacent vertebrae. Degeneration of the disc can cause narrowing of the spinal canal (stenosis) and apply pressure on the nerve roots. This can be experienced as pain which radiates down the thigh and/or leg with walking or standing (neurogenic claudication). If the pressure on the spinal nerve roots continues, numbness or muscle weakness in the leg or foot may develop.

Spondylolisthesis may be the result of trauma, degenerative changes, or a developmental crack in one of the vertebrae. Due to the constant forces experienced in the low back this fracture does not usually heal in an adult, but may not produce significant symptoms. Sometimes the cracked vertebra may slip forward over the vertebra below it. This is known as spondylolisthesis. In some people, this slippage can produce pressure on the nerve roots causing symptoms of back and/or leg pain, typically with walking or standing.

Treatment Options for Spinal Stenosis and Spondylolisthesis

Conservative Management: Backache associated with spinal arthritis is common and usually comes and goes without formal treatment. The best prevention and treatment is staying fit and active. For severe episodes of back or leg pain, with the passage of time and treatment with ice, heat, and short periods of rest, inflammation around the nerve roots can resolve on its own. Steroid injections may help relieve the pain by reducing some of the inflammation around the nerves, allowing the irritated nerve time and space to heal. If this conservative care does not relieve symptoms or if there is progressive neurological damage, surgery may be necessary.

Surgery: There are two general types of surgery done for spinal stenosis or spondylolisthesis: decompression (taking pressure off the nerve roots) and fusion. If there is no instability, decompression alone may help nerve pain going into the buttock and legs. If there is significant instability, the spine may also need to be fused (surgically stabilized) either from the front (anterior) or back (posterior), or both.