- Most patients with acute low back pain improve spontaneously within 4 weeks.
- Degenerative change in the lumbar spine is the most commonly identified cause of low back pain.
- Diagnostic testing is rarely indicated in the absence of significant neurologic involvement or suspicion of systemic disease unless symptoms persist beyond 4 weeks.
- Imaging abnormalities must be interpreted carefully because they are frequently seen in asymptomatic persons.
- Patients with neurologic involvement or an underlying systemic disease (eg, infections, malignancies, and spondyloarthropathies) may need urgent or specific treatment, including surgery.
- Surgery is rarely needed for patients who respond to analgesia, education, aerobic conditioning, and physical therapy.
Low back pain (LBP) is the most common musculoskeletal complaint and a leading cause of work disability. An estimated 80% of the population experiences it during their lifetime.
LBP affects the area between the lower rib cage and gluteal folds and frequently radiates into the thighs. Most LBP is benign and self-limited. Ninety percent of patients with acute LBP improve spontaneously within 4 weeks, although low-grade symptoms may persist in some. Approximately half of the patients with acute LBP experience one or more episodes of LBP over the next few years, but these, too, are generally self-limited. Less than 1% of the patients with acute LBP have true sciatica, which is defined as pain in the distribution of a lumbar nerve root, often accompanied by sensory and motor deficits (Table 10–1 and Figure 10–1).
Table 10–1. Neurologic Features of Lumbosacral Radiculopathy. ||Download (.pdf)
Table 10–1. Neurologic Features of Lumbosacral Radiculopathy.
|Disk Herniation||Nerve Root||Motor||Sensory (Light Touch)||Reflex|
|L3–4||L4||Dorsiflexion of foot||Medial foot||Knee|
|L4–5||L5||Dorsiflexion of great toe||Dorsal foot||None|
|L5–S1||S1||Plantar flexion of foot||Lateral foot||Ankle|
Lower extremity dermatomes.
Risk factors that have been associated with LBP include heavy lifting, driving motor vehicles, jogging, weaker trunk strength, obesity, pregnancy, psychosocial factors, and cigarette smoking.
An important aspect of history-taking in a patient with LBP is the identification of “red flags” to ensure that conditions that require early diagnostic testing are not missed (Table 10–2).
Table 10–2. “Red Flags” that Indicate Need for Early Diagnostic Testing. ||Download (.pdf)
Table 10–2. “Red Flags” that Indicate Need for Early Diagnostic Testing.
- Spinal fracture
- Significant trauma
- Prolonged glucocorticoid use
- Age >50 years
- Infection or cancer
- History of cancer
- Unexplained weight loss
- Injection drug use
- Nocturnal pain
- Age >50 years
- Cauda equina syndrome
- Urinary retention
- Overflow incontinence
- Fecal incontinence
- Bilateral or progressive motor deficit
- Saddle anesthesia
- Marked morning stiffness in the back that lasts >30 min
- Low back pain that improves with activity but not rest
- Alternating buttock pain
- Age <40 ...