Introduction

Physical therapy in Hazle Township for Lower Back

Welcome to FYZICAL Hazleton's patient resource about Lumbar Spondylolisthesis.

Normally, the bones of the spine (the vertebrae) stand neatly stacked on top of one another. Ligaments and joints support the spine. Spondylolisthesis alters the alignment of the spine. In this condition, one of the spine bones slips forward over the one below it. As the bone slips forward, the nearby tissues and nerves may become irritated and painful.

This article will help you understand:

how the problem develops
how doctors diagnose the condition
what treatment options are available

Anatomy

What parts of the spine are involved?

The human spine is made up of 24 spinal bones, called vertebrae. Vertebrae are stacked on top of one another to create the spinal column. The spinal column gives the body its form. It is the body's main upright support. The section of the spine in the lower back is called the lumbar spine.

Spinal Column

The lumbar spine is made of the lower five vertebrae. Doctors often refer to these vertebrae as L1 to L5. These five vertebrae line up to give the low back a slight inward curve. The lowest vertebra of the lumbar spine, L5, connects to the top of the sacrum, a triangular bone at the base of the spine that fits between the two pelvic bones.

Lowest Vertebra

Each vertebra is formed by a round block of bone, called a vertebral body. A circle of bone attaches to the back of the vertebral body. When the vertebrae are stacked on top of each other, these bony rings create a hollow tube. This tube, called the spinal canal, surrounds the spinal cord as it passes through the spine. Just as the skull protects the brain, the bones of the spinal column protect the spinal cord.

Circle of Bone Attaches to Vertebral Body

Spinal Cord

The spinal cord only extends to L2. Below this level, the spinal canal encloses a bundle of nerves that goes to the lower limbs and pelvic organs. The Latin term for this bundle of nerves is cauda equina, meaning horse's tail.

Cauda Equina

Two sets of bones form the spinal canal's bony ring. Two pedicle bones attach to the back of each vertebral body. Two lamina bones complete the ring. The place where the lamina and pedicle bones meet is called the pars interarticularis, or pars for short. There are two such meeting points on the back of each vertebra, one on the left and one on the right. The pars is thought to be the weakest part of the bony ring.

Bony Ring

Intervertebral discs separate the vertebral bodies. The discs normally work like shock absorbers. They protect the spine against the daily pull of gravity. They also protect the spine during strenuous activities that put strong force on the spine, such as jumping, running, and lifting.

The lumbar spine is supported by ligaments and muscles. The ligaments, which connect bones together, are arranged in layers and run in multiple directions. Thick ligaments connect the bones of the lumbar spine to the sacrum (the bone below L5) and pelvis.

Thick Ligaments

Between the vertebrae of each spinal segment are two facet joints. The facet joints are located on the back of the spinal column. There are two facet joints between each pair of vertebrae, one on each side of the spine. A facet joint is made of small, bony knobs that line up along the back of the spine. Where these knobs meet, they form a joint that connects the two vertebrae. The alignment of the facet joints of the lumbar spine allows freedom of movement as you bend forward and back.

Facet Joints

The anatomy of the lumbar spine is often discussed in terms of spinal segments. Each spinal segment includes two vertebrae separated by an intervertebral disc, the nerves that leave the spinal cord at that level, and the facet joints that link each level of the spinal column.

Lumbar Spondylolisthesis