Epidemiology and Etiology of Low Back Pain
Most patients presenting with low back pain in primary care settings will suffer from non-specific back pain. These patients will generally improve within a few weeks to several weeks with conservative or self-care. Less than 1 percent will have serious etiologies (e.g., malignant tumor or infection). Less than 10 percent will have less serious specific etiologies (e.g., vertebral compression fracture, radiculopathy, or spinal stenosis).
Initial Evaluation of Low Back Pain
A focused history and physical examination are sufficient to evaluate most patients with back pain lasting less than four weeks. The history and physical examination should identify features suggesting that imaging and/or further evaluations are indicated.
● Imaging is not indicated for most patients with acute low back pain –The majority of patients with low back pain of less than four weeks do not require imaging. Among patients seen in primary care, less than 1 percent will require immediate advanced imaging (e.g., magnetic resonance imaging [MRI] or computed tomography [CT]).
Any patient with symptoms of spinal cord or cauda equina compression or progressive and/or severe neurological deficits should undergo an immediate MRI of the lumbar spine for further evaluation and urgent referral to a specialist. These symptoms and signs include new urinary retention, overflow bladder incontinence, new fecal incontinence, saddle anesthesia, and significant motor deficits not localized to a single nerve root.
Other patients who may require imaging during the initial evaluation include those with moderate to high suspicion of spinal infection, risk factors for metastatic cancer, and suspicion of vertebral compression fracture.
Further Evaluation of Patients with Persistent Symptoms
Patients who have not improved after four to six weeks of conservative treatment and who did not receive imaging during the initial evaluation are re-evaluated:
Patients with persistent symptoms due to lumbosacral radiculopathy or spinal stenosis who are candidates and interested in invasive therapies (e.g., surgery or epidural injection for radiculopathy) should undergo an MRI of the lumbar spine for further evaluation.
In patients with low back pain who have risk factors for cancer, we assess the erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) and plain radiographs.
Other patients who may need imaging include those concerned about axial spondyloarthritis and osteoarthritis.
In other patients for whom there is no concern about a particular etiology, we generally treat with conservative treatment for an additional eight weeks.
For patients without concern about a particular etiology and who have not improved after a total of 12 weeks, we generally perform imaging with a plain radiograph and consider referrals for further evaluation and treatment.
Source: UpToDate