The first step of evaluation is to ensure that the back pain is not a harbinger of a serious medical condition. Thus tumor, infection, fracture, and instability should be excluded. A patient’s medical history often provides enough information to determine whether ra- diographs are needed on the first visit. When a patient has had back pain for 6 weeks or longer, imaging studies are usually required.
It is unlikely that an adult younger than 50 years with no history of a prior malignancy has a tumor; the odds are even lower when a patient has no constitutional com- plaints, such as fever, weight loss, or night pain. Infection, likewise, is rare in an other- wise healthy patient. The medical history should include questions about possible immune system compromise (eg, human immunodeficiency virus or use of immune- suppressing drugs, such as steroids) or intravenous drug use. Patients with diabetes mellitus or sickle cell anemia are also prone to bone infections.
Fractures and instabilities are rare unless there is a history of trauma. The exception is a patient with osteoporosis. Osteoporosis may be a typical postmenopausal condition, but it also should be considered as a secondary condition in patients with a history of long-term steroid use, a metabolic abnormality, or recent lactation.
Low back pain may originate from the many discrete anatomic structures in the spine itself, such as the disk, the vertebral body, the spinal nerve roots, the facet joints and their ligaments, and the paraspinal muscles. There also may be a visceral cause for the pain, such as an abdominal aortic aneurysm or kidney infection. The leg pain of sciatica may mimic peripheral nerve diseases or vascular insufficiency. Worrisome findings that should prompt diligent investigation include night pain, pain at rest, fever, unintentional weight loss, acute motor weakness, and unremitting pain of increased severity.
Treatment and Prevention
Back pain resolves spontaneously in most patients; therefore, the principal treatment for most mechanical back pain is to simply “do no harm” as natural recovery takes place. Should diagnostic imaging studies reveal disk degeneration without compression of the spinal nerves, physical therapy with an emphasis on lumbar strengthening and flexibility is indicated. Patients with sciatica and MRI evidence of nerve root compression caused by a disk herniation may benefit from epidural steroid injections to reduce the inflammation around the nerve roots.
The use of anti-inflammatory and mild analgesic medications may aid symptom relief, although some patients will require short courses of narcotic pain relievers. Bed rest is considered inappropriate because it induces atrophy and weakness, although activity modification, such as the avoidance of lift- ing, may be useful in hastening recovery and preventing recurrence. In the acute phase of low back pain, physical therapy modalities, such as heat, ice, and ultrasound may pro- vide relief; however, there is no evidence- based literature to support these treatments.4 Therapy should also include “back school” to educate the patient about proper posture and lifting techniques.
Surgery for sciatica is reserved for patients who do not improve after a few months and are willing to assume the risks of surgery. Diskectomy (surgical removal of the herniated disk material) offers patients the chance for a more rapid initial recovery, especially for radicular symptoms in the legs. However, after a period of years, patients who have had surgery are functionally indistinguishable from patients who have not had surgery.5 Surgical fusion for back pain remains a controversial topic.
Preventing back pain is also an area of active investigation. Some believe that a program of spinal and abdominal muscle strengthening exercises may reduce the incidence of low back pain. Furthermore, patients are less de- bilitated by pain if they are fit and exercise regularly. Using education about spinal biomechanics as a preventive strategy has produced mixed results. Decreasing risk factors, such as smoking and obesity, has the force of logic, but there is no evidence that attempting to modulate these risk factors is effective in preventing back pain.