SAN DIEGO — The good news about low back pain is that it's often self-resolving. The bad news is it tends to reoccur.
“One in five people at any time will have low back pain,” said Dr. Francis O'Connor, medical director of the Consortium for Health and Military Performance at the Uniformed Services University of the Health Sciences, Bethesda, Md.
About 40%–50% of patients improve within 1 week, regardless of the type of intervention. In injured workers, 85%–90% “are going to improve within 6–12 weeks. So the natural history of acute low back pain is fairly favorable.”
But overall, 40% of patients report a recurrence of low back pain within 6 months of follow-up and 44% are in a chronic phase within 2 years.
“In over 85% of cases of low back pain, no definitive diagnosis can be made. There are so many structures that cause back pain or referred pain that it's difficult to pin it on one particular structure,” said Dr. O'Connor at the annual meeting of the American Academy of Family Physicians.
Clinical assessment of patients with low back pain should begin with an observation of posture. “We're looking for asymmetry, atrophy, and function,” he said. “You [also] want to look for skin lesions like café-au-lait spots, which may be a clue to underlying neurofibromatosis, or a hairy patch, which might be related to an underlying neurodegenerative process.”
Lipomas may indicate spina bifida occulta; and asymmetry between the shoulders and pelvis might be a clue for an underlying muscular spasm or fixed deformity.
Making note of the patient's lordosis is also advised. “If it's exaggerated, that could be a characteristic of a weak abdominal wall or spondylolisthesis.”
Other components of a clinical work-up should include palpation of the back, range-of-motion testing, gait assessment, and a neurologic exam to evaluate motor and sensory function.
One should also evaluate for Waddell's signs—nonorganic signs indicating the presence of a functional component of back pain. The signs are superficial, nonanatomic tenderness; pain with simulated testing; inconsistent responses with distraction; nonorganic regional disturbances; and overreaction verbally or with exaggerated body language. Being positive for three of the five suggests a nonorganic etiology and a poor potential outcome with operative intervention, Dr. O'Connor said.
Within 6 months of follow-up, 40% of patients report a recurrence of low back pain; 44% are in a chronic phase in 2 years. DR. O'CONNOR