Epidemiology, etiology, diagnostic evaluation, and treatment of low back pain.

New data concerning the epidemiology, etiology, diagnostic evaluation, and treatment of low back pain have been reported over the past year. Low back pain remains an expensive health problem for our country costing an estimated 24 billion dollars in direct medical expenses. The degeneration of intervertebral disks may be associated with the appearance of increased amounts of specific collagen types that are not present in normal disk specimens. In an important study of monozygotic twins, smoking was identified as an independent variable associated with advanced degeneration of intervertebral disks. Sacral insufficiency fractures are a significant cause of back pain particularly in elderly individuals with predisposing disorders and medications. Radiographic techniques continue to improve and offer earlier detection of the anatomic abnormalities associated with clinical disorders including inflammatory myelitis. Epidural corticosteroid injections are helpful for decreasing symptoms of radiculopathy, but the injections may only be placed in the correct location in the epidural space 50% of the time unless corroborated by radiographic techniques. Chiropractors suggest that manipulation therapy is cost effective for treatment of low back pain in comparison with therapies given by physicians.