The spine is comprised of bones called vertebra and soft spongy discs that separate the vertebrae. Housed within the spine are the spinal cord and delicate spinal nerves. Degeneration of any of these structures can occur through injury, poor posture, aging or disease. There are many different descriptive terms that can be used, such as spondylosis, osteoarthritis and degenerative arthritis, but each is referring to the wear and tear breakdown of discs, joint surfaces and surrounding soft tissue.
According to Spine Universe, osteoarthritis is the most common form of arthritis and affects more than 20 million Americans. Symptoms of degeneration include pain, loss of range of motion, numbness and tingling and muscle weakness.
Disc Degeneration
Spinal discs have a tough fibrous outer ring called the annulus that helps contain the soft jellylike center of the disc, called the nucleus. When healthy, the disc is well-hydrated and helps to absorb shock and aid in movement, but according to the University of California, San Diego, one of the earliest signs of disc degeneration is a loss of water content. As the disc dries out, cracks begin to form in the annulus, allowing a portion of the nucleus to bulge and herniate out beyond its normal confines, which puts pressure on nearby spinal nerves. Disc degeneration can be assumed by visualized narrowing of the space between the vertebra on a plain film x-ray, and disc herniations can be seen on MRI.
Facet Arthrosis
On the backside of the spine at each level, there are two small joints where each vertebra meets another. These joints are referred to as facet joints and help direct the plane of motion at that segment. Normally, facet joints glide smoothly over one another during motion of the spine, but degenerative changes wear out the cartilage between the joints and cause arthritic bone growth, or hypertrophy, to occur, according to orthopedic surgeon Dr. Mark Wolgin. One of the primary symptoms of facet degeneration is low back pain, especially with extension of the spine.
Joint Surface Degeneration
When spinal degenerative changes occur, the ligaments that provide stability and the discs that provide shock absorption wear out, and those spinal segments affected become unstable. Additionally, as discs narrow, extra stress is placed directly onto the bony surfaces of the joint. The body's normal response to this condition of added stress and instability is to lay down new bone growth. Osteophytes, or bone spurs, are protruding pieces of bone that grow in response to this added stress. They can cause stiffness of the spine and may affect nearby nerves or other soft tissue, according MayoClinic.com.
