Chronic Back Pain

Back pain is a widespread, debilitating disorder that results in an enormous socioeconomic burden. The lifetime prevalence of low back pain ranges from 60 to 90%, and the annual incidence is ~5% (Frymoyer 1988; Frymoyer 1992). The annual cost to treat chronic back pain has been estimated to exceed $100 billion, of which up to $50 billion is due to lost productivity (Crow & Willis 2009).

A specific type of back pain in the distribution of lumbosacral nerves is known as lumbosacral radicular pain, which is frequently referred to as sciatica. It is a common condition with a lifetime incidence varying from 13% to 40% (Stafford et al. 2007). The corresponding annual incidence of an episode of lumbosacral radicular pain ranges from 1% to 5% (Frymoyer 1988; Frymoyer 1992). It is rarely diagnosed before the age of 20, peaks in incidence in the fifth decade and declines thereafter (Frymoyer 1992).

Lumbosacral radiculopathy is believed to result most commonly from prolapsed disc material causing pain secondary to mechanical impingement and/or inflammation of the anterior primary rami of lumbar nerve roots (Lindahl & Rexed 1951). Approximately 90% of cases of lumbosacral radicular pain are caused by a herniated disc with nerve root compression, with various other etiologies accounting for the remaining 10% of the cases (Stafford et al. 2007; Valat et al. 2010).

There are several conservative treatments for lumbosacral radicular pain, each with varying levels of effectiveness. These therapeutic approaches include bed rest, staying active (in contrast to bed rest), analgesic or non-steroidal anti-inflammatory drugs (specifically opioids and benzodiazepines), acupuncture, spinal manipulations, traction therapy, physical therapy, behavioral treatment, and epidural steroid injections (Frymoyer 1992; Koes et al. 2007; Valat et al. 2010). The initial phase of sciatica frequently responds to conservative management. In some cases, when these more conservative treatments for lumbosacral radicular pain are ineffective, surgical intervention has been explored as a treatment option. The comparative effectiveness of the various treatment modalities has been a topic frequently addressed in the literature, but there is currently no FDA-approved epidural steroid treatment for lumbosacral radicular pain.