Back Pain in the Elderly

The evaluation and management of back pain in older patients is more complex and challenging than in younger patients. Low back pain in the elderly has a much wider range of possible diagnoses, including a much higher incidence of malignant or visceral causes.

The overriding objectives in assessing the older person with back pain are to differentiate common musculoskeletal pain from serious visceral or nonspinal pain; identify patients with primary radicular pain; identify comorbidities; and recognize complicating psychosocial issues.

Classifying the pain into acute (fewer than four weeks in duration), sub-acute or chronic (beyond four weeks in duration), and pain with associated leg pain is useful in planning the workup.

Acute causes:
• Lumbar strain/sprain
• Osteoporotic fracture, vertebral or pelvic
• Abdominal aortic aneurysm

Subacute/chronic:
• Degenerative disk and joint disease (mechanical degenerative)
• Malignancy
• Fibromyalgia
• Polymyalgia rheumatica
• Parkinson’s disease
• Paget’s disease
• Diffuse idiopathic skeletal hyperostosis (DISH)

Predominant leg pain associated with back pain:
• Trochanteric bursitis
• Osteoarthritis of the hip
• Lumbar canal stenosis

Evaluation
Evaluation begins with a careful history and physical examination, even more critical in older patients because of the broader differential diagnoses and higher frequency of comorbid conditions. Four areas should be assessed when taking the history of the older patient:

• Characteristics of the pain
• Red flags for cancer
• Nonspinal medical problems
• Psychosocial factors

Pain characteristics

Location: Pain radiating below the knee strongly suggests lower lumbar radiculopathy, while pain localized to the upper anterior thigh or groin suggests upper lumbar radiculopathy or hip disease. Pain over the lateral hip may implicate trochanteric bursitis.

Onset: Knowing whether the pain is acute or insidious in onset helps narrow the differential diagnosis. Degenerative mechanical pain typically has a gradual onset, while pain secondary to an osteoporotic compression fracture is usually sudden and severe.

Positional change: Malignant or visceral pain is usually constant, irrespective of position, while mechanical pain often subsides when the patient is supine and worsens with movement. Most patients with leg symptoms due to spinal stenosis are more comfortable sitting than standing.

Red flags for cancer
Malignant diseases are the cause of back pain in as many as 7 percent of patients over age 50. Consider these red flags:

• Prior history of cancer
• Pain that is usually constant
• Pain at night that disturbs sleep
• Unexplained weight loss of more than 10 pounds in three months
• Back pain that progresses despite appropriate treatment

Nonspinal medical conditions
Certain medical conditions may confound the diagnosis and affect treatment choices. Diabetes-related peripheral vascular disease, diabetic neuropathy or polyradiculopathy may superficially mimic the neurogenic claudication of spinal stenosis. Ischemic heart disease and congestive heart failure, like diabetes, places patients at increased risk of NSAID-related nephrotoxicity and gastrointestinal toxicity.

Psychosocial factors
Nonorganic issues, including psychologic ones, often complicate the management of low back pain in patients of all ages. For a frail, elderly patient, the onset of back pain may seriously compromise an already marginally functional status, thereby threatening independence. The needs of an ill or disabled spouse may prevent the older adult with back pain from seeking or complying with treatment. Even mild cognitive impairment (e.g., dementia) significantly limits therapeutic choices.

Mental and physical function must be carefully assessed in the elderly patient and may necessitate extended social services.

Physical examination
The examination of the elderly patient includes observations and maneuvers performed in all age groups, with certain areas receiving special attention. The physical examination should include careful observation of posture, looking for increased thoracic kyphosis, characteristic of vertebral compression. Increased muscle tone and stiffness may suggest Parkinson’s disease. Assessing distal pulses is important in distinguishing vascular from neurogenic claudication.

Imaging
Imaging studies must be interpreted cautiously in the older patient because irrelevant, false-positive findings increase with age. Spine radiographs only need to be performed in persons older than 50 years when symptoms are unimproved by four weeks. Unless malignancy or infectious causes are suspected, CT or MRI is not indicated in most older patients with back pain. Both demonstrate abnormalities in at least 50 percent of asymptomatic persons older than 40 years, and the likelihood of such abnormalities increases with age.

Treatment Options
The most common cause of chronic back pain in the elderly remains nonspecific multilevel degenerative disk and joint disease with associated myofascial strain or sprain. Treatment is directed at relief of symptoms and improvement in function. Pharmacological and nonpharmacological approaches may be combined for best results with least risk of toxicity. Treating associated depression and poor sleep can help improve pain and mood. Surgery is rarely appropriate.

For acute back pain, physical activity shortens the duration of symptoms. But for older patients with chronic back pain, the role of exercise is not well studied and there are safety concerns due to patients’ comorbid conditions and general frailty. “Passive modalities,” such as heat, ultrasound, massage or ice, may provide temporary relief. Participation in group exercise activities has not been studied, though it has been shown to benefit older persons with osteoarthritis of the knee.

Occupational and physical therapists play an important role in educating patients about their back pain. Chiropractic manipulation, particularly highvelocity manipulation, may risk spinal fracture in the older patient.

Lumbar support can improve symptoms in patients with mechanical, degenerative back pain. An appropriately sized cane may assist coexisting hip or knee osteoarthritis and can relieve some back symptoms. Transcutaneous electrical nerve stimulation (TENS) has been shown no more effective than placebo. The neutraceuticals glucosamine and chondritin have in some trials been shown as effective as NSAIDs. However, long-term toxicity has not been studied, and concerns remain about contamination and impurities.

Acetominophen should be the firstline analgesic for most older patients with mechanical degenerative back pain. The risk of toxicity is the greatest factor in deciding whether to prescribe NSAIDs, and they are strongly contraindicated in older patients with a history of congestive heart failure or ulcers. Cyclooxygenase- 2 (COX-2) inhibiting NSAIDs are less toxic to the GI system. Long-term opioid maintenance therapy is gaining acceptance for carefully selected and monitored patients with chronic nonmalignant back pain. Finally, tricyclic antidepressants can help improve the quality of sleep and reduce pain in some patients.

General References
Ettinger WH, et al. A randomized trial comparing aerobic exercise and resistance exercise with a health education program in older adults with knee osteoarthritis. The fitness arthritis and seniors trial (FAST). JAMA 1997;277:25-31.

AGS Panel on Chronic Pain in Older Persons. The Management of Chronic Pain in Older Persons. JAGS 1998;46:635-651.