To help you gain a better understanding of lumbar spinal stenosis (LSS), let’s take a look at the anatomy of the spine. Knowing the names of different parts of your spine can also help you have more informed discussions with your doctor about your condition.

Vertebrae

The spine is made up of 24 back bones called vertebrae. They stack up to provide a strong pillar of support for your head and body, and to enclose and protect a column of nerve tissues called the spinal cord. There are five (5) lumbar, or lower back, vertebrae.

Lamina

For each vertebra, two lamina connect to form the roof of your spinal canal protecting your spinal cord.

Spinous processes

The slender bones protruding from each of your vertebrae are called the spinous processes. These are the bones that create the “bumps” you feel when you run your fingers down the middle of your back.

Ligaments

The 24 vertebrae are connected by soft elastic bands of tissue called ligaments. One of the most important ligaments in the spine is the ligamentum flavum. This large, long, and very strong ligament runs along the inside of the spinal canal connecting the laminae of the vertebrae together.

The ligamentum flavum protects the nerve tissue and the nerves that branch out from the spinal cord. It also stabilizes the spine—preventing too much motion between the vertebral bodies.

Another ligament, called the supraspinous ligament, passes over and attaches the tips of the spinous processes.

Discs

Between the vertebrae are the intervertebral discs, which act as cushions or shock absorbers. Each disc is made up of a tough, flexible outer band called the annulus fibrosus. Inside the disc is a soft gel-like substance called the nucleus pulposus. As we age, our discs may dry out and break down. Disc deterioration or degeneration is one of the factors that worsen LSS.

The spinal cord

Nerves are the most important part of your spinal anatomy because they send messages from your brain to the rest of your body. The spinal cord, which is composed of nerve tissue, starts at the brain and extends down to the pelvis. Individual nerves pass through a ring in each vertebra called a foramen. These vertebral foramina form the spinal canal and serve to protect the spinal cord.

Nerves branch out of the spinal cord between each side of the vertebra, one to the left and one to the right. In the lumbar level of your spine, nerves from the spinal cord exit the spine through foramen and travel down your legs.

See why changes to the disc cause painful symptoms.

LSS is the narrowing of the spinal canal and foramen that causes nerves branching out from the spinal cord and traveling to the legs to become pinched. This can lead to pain in your lower back or legs—especially when you stand or walk; numbness, weakness, stiffness, or dull cramping pain in the lower back and legs; and painful tingling or a pins-and-needles sensation that shoots down the back of your legs.

Learn how the X-STOP Spacer may relieve painful symptoms of LSS.