Lower back pain, the most common pain in adults, is responsible for a large number of missed workdays, and is the most common musculoskeletal complaint seen in emergency departments. It may be classified as acute (less than six week’s duration), sub-chronic (six to 12 weeks), or chronic (more than 12 weeks). Mechanical back pain (also known as lumbago), meaning no pain or numbness below the buttocks, is usually self-limited with up to 90 percent of people completely better by six weeks. There are red flags which may signal a more serious cause of the pain and they include a history of cancer, unexplained weight loss, loss of bladder or bowel control, numbness, pain or tingling below the buttocks, fever and recent (within one year) history of lumbar spine surgery.
There are only a few useful physical diagnostic tests to determine the severity of lower back pain and they include the straight leg raise test and deep tendon reflexes. Most medical societies and experts agree that imaging studies for lower back pain without any red flags are not indicated, as most of these patients will improve on their own. Despite that advice, lumbar MRI scans in the U.S. Medicare population increased by 300 percent from 1994 to 2006. MRI scans for those with mechanical back pain and no red flags can be misleading and may often lead to unnecessary additional tests and procedures. A main reason for this is that many studies have shown that in adults aged 40 with no back pain up to 50 percent will have herniated discs on spinal MRI and that the percentage of asymptomatic herniations increases with age. Likewise lumbar X-rays are not indicated unless there is a history of trauma or a fracture is suspected. If scanning is indicated, MRI is preferred over CT as CT scanning imparts a sizeable amount of radiation to the patient and in general MRI scanning has better resolution than CT scanning.
Treatment of mechanical back pain consists of both pharmaceutical and non-pharmaceutical methods. Medications include Tylenol, OTC NSAIDS (Advil, Aleve), prescription NSAIDs (naproxen), COX-2 inhibitors (Mobic, Celebrex), and muscle relaxants (cyclobenzaprine). Narcotics are almost never indicated in the acute phase because of the high incidence of side effects and the high risk of abuse, diversion and addiction. Non-pharmaceutical treatments include walking, weight loss, and physical therapy. Traditional medical literature gives mixed results for chiropractic and spinal manipulation therapies. In addition there is tentative evidence to support the use of heat in the acute phase but does not support heat or cold therapies for chronic pain.
As for surgical treatment for chronic back pain, discectomy can be of benefit, however the literature shows that over time (i.e. 10 years), that benefit dissipates. Epidural steroid injections show little long-term benefit and the risk of complications including spinal fluid leaks and infections is not insignificant. Recent literature shows that spinal fusion, when performed for spinal stenosis, often does not change the long-term outcome.