It may surprise you to know that sciatica is not technically a back condition. Instead, it is a set of symptoms associated with spinal and/or hip conditions such as a herniated disk in the low back, spinal stenosis, or the relatively rare piriformis syndrome.
There are several causes of sciatica. It may be due to one or more problems in the spine, for example, herniated disk, spinal stenosis or bone spurs from arthritis. These conditions all, in one way or another, compress spinal structures, and the large sciatic nerve, causing pain. Piriformis syndrome also compresses the sciatic nerve, but this time by a butt muscle known as the piriformis. The sciatic nerve runs just in front of the piriformis and is easily pressured by it.
Pregnancy can also bring about sciatica. Still another type of sciatica is related to an unstable sacroiliac joint and its affect on the sciatic nerve as it exits the spine as a plexus, or grouping of nerve roots. There are several less common causes of sciatica including tumors, infections, and total hip replacement for congenitally dislocating hips.
Very often, sciatica will go away on its own, or will respond well to conservative treatment methods. Sometimes, however, sciatica is treated with surgery to repair the herniated disk or to make more space in the vertebrae. A September 2005 review of studies sponsored by the U.S. Agency on Healthcare Research and Quality revealed that over the long term, reduction of pain was approximately the same between sciatica patients treated with surgery and those treated without surgery. In these 3 studies, a total of 544 sciatica patients were followed for 10 years.
Kendall, F., McCreary, E., & Provance, P. (1993). Muscles: Testing and Function with Posture and Pain. Baltimore: Williams & Wilkins.
Wheeless' Book of Orthopaedics. Retrieved January 10, 2007, from Duke Orthopaedics Web site: http://www.wheelessonline.com/ortho/greater_sciatic_foramen
(Sept 2005). Outcomes/Effectivness Research. Patients with sciatica and lumbar disc herniation or spinal stenosis treated surgically or medically have similar 10-year outcomes. Retrieved January 10, 2007, from Agency for Health Care and Quality Web site: http://www.ahrq.gov/research/sep05/0905RA29.htm