Sciatica is the pinched nerve feeling in the back that causes back pain with a radiating pain to the hips to the legs. As an Orthopaedic Spine Specialist, it is probably the most common complaint of my patients. In the most simplest definition, sciatica is a pinching of the nerve that goes from the spine into the legs.
The review article confirms that the most common causes for sciatica are herniated disks or bone spurs in the back. The sciatic nerve components are pinched within the spine with disk herniations and spine bone spurs. There are sciatica conditions that are caused by pinching outside the spine. There are also conditions that cause sciatica complaints not related to the spine.
Non Spine Causes of Sciatica include:
- Hip arthritis. Problems with the hip joints including arthritis, bursitis, sacroilitis can cause similar back and thigh pains.
- Reduced blood supply. Some patients have narrowing of the blood supply in the arteries to the legs. With activities such as exercise, or walking, it may cause pain to the legs.
- Tumors. This one usually gets peoples attention. On rare occasions, the pinched nerve sensation is secondary to a tumor (benign or cancerous) that grows in the pelvis, and pinches the nerves as the nerve travels outside the spine canal into the legs. The Spine bone, is connected to the hip bone, which connects to the thigh bone, and so on. Likewise, the nerves go from your spine, past the hips, into the legs. A tumor located outside the spine, can pinch the nerve as it travels to the leg.
- Peripheral Neuropathy. Certain medical conditions such as diabetes causes damage to the nerves outside the spine. This damage to the outside the spine is Peripheral Neuropathy.
- Outside Nerve Compression. As stated above, the sciatic nerve components travel outside the spine, into the legs. Sometimes, muscles, ligaments, and collections of fluids, called cysts can also cause pinching of the nerve components. These nerves can also be compressed by swelling of the tissues from a trauma, or infection.
- Iliac artery aneurysms (a bubble like weakness in the wall of the artery) can also get large enough to cause the same compression symptoms as above.
Fortunately, most episodes of sciatica resolve, or improve with time. On the other hand, increasing pain, weakness, and numbness may mean a continuing worsening process. If you have concerns, please have it evaluated by your physician.
- Jeon IC, Kim SW, Jung YJ. Large sized common iliac artery aneurysm with thrombus developing a diagnostic confusion in a patient with sciatica. Korean J Pain. 2014 Oct;27(4):360-4. PubMed PMID: 25317286