Sciatica's (pronounced sigh-AT-eh-ka) hallmarks are pain and numbness that radiates down the leg, often below the knee. In nine out of 10 cases, sciatica is caused by a displaced disk in the lower spine.

The best medicine is often patience — with some stoicism mixed in — because the pain often goes away, even if the problem disk does not. Researchers have found that the pain usually improves within a month. No one is quite sure why the pain subsides on its own, but it does.

But if the pain is very bad or persists, many people with sciatica must decide whether to have surgery. There are several sorts of operations, but they all involve paring back disks in some way so they don't impinge on nerve roots. And these aren't high-risk operations — complications are rare.

Still, the message from a couple of important studies has been mixed to downright muddy, because after a year or two, the outcomes for surgical patients and those treated "conservatively" (with physical therapy or pain relievers) converge and are roughly the same.

Symptoms and diagnosis

Each leg has a long sciatic nerve that runs through the buttock, down the back of the thigh, and into the foot and toes. Sciatica is pain felt along the course of those nerves and their branches, so while the problem originates in the lower lumbar region of the spine, the symptoms are felt mainly in the legs.

Many people with the condition have a history of back problems, but sciatica often starts suddenly. It can be triggered by something minor — even a sneeze. The pain is often sharp and stabbing and confined to one leg. Numbness, unpleasant tingling sensations, and weakness in the affected leg are common.

Sciatica, by definition, is a set of symptoms, so the diagnosis tends to be based largely on patient accounts of what they've been feeling. A straight-leg test is a fast, inexpensive way to tell if there is a herniated disk. The examiner lifts the leg while the patient is lying on his or her back. If lifting the leg reproduces the sciatic pain, that's a good clue that there's a protruding disk of some kind.

An MRI can provide more direct evidence of a disk problem, but many doctors and some guidelines recommend holding off on getting an imaging test till surgery is a serious option. If the pain goes away, as it often does, then such tests are unnecessary.

Treatment choices

Conservative treatment — a catchall term for everything but surgery — of sciatica used to emphasize inactivity, even bed rest. But that's changed, so clinicians now typically advise patients to keep up their daily activities as much as possible. Pain relievers — usually just the standard nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and naproxen — are often prescribed. Physical therapy can help strengthen muscles in the abdomen and around the spine, which may take some pressure off the disks. If none of this works, some doctors try injecting corticosteroids, which have a strong anti-inflammatory effect, directly into the spine. Corticosteroid injections can reduce inflammation and relieve pain for weeks to months. Anesthetic injections may also be given.

Most sciatica patients are advised to give conservative treatment a try before considering surgery. For how long is debatable, but the usual timetable is six to eight weeks.

The question with disk surgery is not whether it works to relieve sciatic pain. It does, and recovery times are shorter than ever as less-invasive techniques have been developed. The issue is whether surgery makes any difference in the long run, and if it doesn't, whether it is worth the risk and expense. Research published in the early 1980s suggested that having surgery relieved symptoms faster than conservative treatment, but that four years later, the difference narrowed, and the surgical and nonsurgical patients had roughly the same outcome.

A study published in 2007 looked at outcomes one year later and came to a similar conclusion.

So the bottom line here is a wavy one, with personal preference and individual circumstance playing a big role. A large percentage — some sources put it at 80% — of sciatica patients with displaced disks get better without surgery, which certainly argues for go-slow, conservative management. On the other hand, if your sciatic pain is incapacitating, as it often can be, then surgery is a choice.

March 2009 update