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 discs made of cartilage with a softer substance in the center. The tip of the triangular bone is the tailbone, or coccyx.
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, 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 called sciatica) or the spinal cord (one cause of thigh muscle weakness with walking).
A herniated disc may be the result of a lifting injury, or repetitive use of the low back in such a way that the discs become weakened.
The symptoms of a disc herniation depend on which part of the disc ruptures, and whether or not the nerves in the spine are affected. It may cause burning pain, numbness or electric shock-like pain into the legs. This may be worse with coughing, sneezing or with straining during bowel movements. Severely pinched nerves may cause leg weakness. Difficulty controlling urine or the bowels is a sign of an emergency requiring urgent evaluation and treatment.
Usually a history and physical exam may strongly suggest that a disc has herniated. X-rays of the lumbar spine are often not necessary for the diagnosis or to start treatment, but they may show narrowing of the disc spaces, the alignment of the spine, and the location of calcium buildup (bone spurs). They may also show unexpected conditions causing the pain.
Generally surgery is not helpful for routine low back arthritis symptoms. Surgery is considered and often 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. Sometimes the spine is unstable and may be realigned with surgery. Many different treatments are tried, including physical therapy, aquatic exercise, ‘cortisone’ injections, chiropractic care, various medications, biofeedback, minimally invasive surgery and exercises including stretching. The best approach is the one that is individualized and provides the most relief, with the fewest side effects.