The lower back or lumbar spine is made of a stack of 5 block-like bones called vertebrae with a triangular bone attached underneath. These bones are separated by five oval cushions called the ‘discs’ made of cartilage with a softer substance in the center. The tip of the triangular bone is the tailbone, or coccyx.
If the discs become thin or worn the disease is called degenerative disc disease. If the soft jelly-like center in the middle of the disc is pushed through the outer disc, a herniated disc occurs – sometimes called a disc protrusion, bulging disc, or 'slipped disc' . Even though the term slipped disc is used to describe a herniated disc, the disc does not slip out of place. Sometimes this will cause a pinching or compressing of the spinal nerves (causing pain into the buttocks or legs) or the spinal cord (one cause of thigh muscle weakness with walking).
Degenerative disc disease is a form of arthritis in the low back. The cause may be from an old injury, or overuse causing repetitive stress on the spine. If the discs become thin, torn or ragged extra calcium grows around the spinal joints and the edges of the spinal vertebrae resulting in 'bone spurs' . This calcium buildup is similar to that seen in the knuckles in people with osteoarthritis in their fingers. The calcium deposits may pinch nerves or compress the spinal cord.
The symptoms of low back pain are different in many people, depending on which areas of the low back are affected. In general, the back aches, feels stiff and may improve once the individual gets up and moves around. The pain often becomes worse with standing too long, walking or bending over. Pain when standing up from sitting in a chair is often the most annoying symptom. If the pain is worse at night, other more serious causes of the pain should be considered.
X-rays of the lumbar spine are often not necessary to start treatment, but they may show narrowing of the disc spaces, the alignment of the spine, and the location of calcium buildup. They may also show unexpected conditions causing the pain.
Generally surgery is not helpful for routine low back arthritis. Surgery is considered and helpful if nerves are being severely pinched causing pain or weakness in the legs or if the spinal cord is compressed to a point where the legs become very weak with walking just a short distance. Many different treatments are tried, including physical therapy, aquatic exercise, 'cortisone' injections, chiropractic care, various medications and exercises including stretching. The best approach is individualized to provide the best relief, with the fewest side effects.