The Patient With Back Pain

Issue: October 2016

A 35-year-old man presents to the office with a complaint of low back pain for the past 6 months. The pain has gotten progressively worse, occurring in the morning and evening with no radiation into the legs or buttocks and no relief with lying down or resting. Ibuprofen and acetaminophen have not provided significant relief. He says exercise seems to relieve his pain. The patient says his father had spondyloarthritis that began at about the same age, resulting in progressive disability and immobility.

Physical exam reveals restricted movement and pain with lumbar flexion spine. There is no tenderness or pain over the sacroiliac joints.

Laboratory studies shows his C-reactive protein (CRP) level is 21 mg/dL. radiographs of the lumbosacral spine and pelvis are normal.

Key Supporting Information

Back pain is a common disorder; nearly 80% of adults will experience low back pain (LBP) during the course of their lifetime. Worldwide, LBP is responsible for more disability than any other condition in the United States, 19.3% of the population between 20 years and 65 years has back pain.

When due to mechanical damage, LBP normally resolves within 2 weeks to 4 weeks; conversely, inflammatory back pain (IBP) is chronic, lasting longer than 3 months. In most cases, back pain is caused by mechanical and degenerative damage, inflammatory processes and infections, as well as tumors that can involve muscles, ligaments or discs. Local pain and/or tenderness can result from neural irritation or impingement from bulging or herniated intervertebral discs, compressing the nerve endings in the posterior longitudinal ligaments or annulus fibrosis. Referred pain can result from deep structures and subsequently may be felt at a distant site with the same neural dermatome. Musculoskeletal pain can be the result of paraspinal muscle spasm due to an injury or a structural spinal abnormality. Radicular pain occurs from angulation, compression or stretching of the nerve roots.

One of the most useful screening factors in evaluation of a patient with the LBP is age. Spinal stenosis, carcinomas and compression fractures are more common in older individuals. Spondyloarthropathies usually present before 40 years. Key findings that point to a central spinal cord compression are bladder and bowel dysfunction, bilateral or multilevel neurological deficits and impaired sensation.

In patients demonstrating rapidly progressive neurological symptoms and findings, MRI is the preferred modality due to better visualization of the soft tissues and spinal canal, especially when there is a concern for osteomyelitis, cauda equina syndrome or epidural abscess.

Differential Diagnosis

Mechanical

Congenital: Spinal stenosis, scoliosis, spondylolisthesis, spondylolysis or transitional vertebra
Degenerative: Disc protrusion, osteoarthritis or spinal stenosis

Metabolic

Paget’s disease or osteoporosis

Tumors

Benign bone (osteoid osteoma, hemangioma), malignant (metastatic, multiple myeloma) or neural (meningioma)

Infections

Herpes zoster, tuberculosis, epidural or subdural abscess, meningitis

Inflammatory Diseases

Ankylosing spondylitis, psoriatic arthropathy, rheumatoid arthritis or enteropathic arthropathy

Neural Impingement Syndromes

Intercostal nerve entrapment or cauda equina syndrome

Muscle

Myofascial spasm

Trauma

Compression fracture, lumbosacral or sacroiliac strain, subluxation

Referred Pain

Aortic aneurysm, pelvic or retroperitoneal disease, renal stones renal infection

Axial spondyloarthritis (AxSpA) is a type of arthritis in which the primary symptom is back pain. The classification of AxSpA is dependent on presence of IBP; it is diagnosed as ankylosing spondylitis (AS) if damage to the sacroiliac joints is evidenced by radiograph, or non-radiographic (nr-AxSpA) if damage is not present on radiographs. However, most patients with nr-AxSpA show inflammation of the spine via MRI. As there are distinct treatment options for mechanical back pain and IBP, making an accurate and timely diagnosis of the underlying cause of the back pain is critical to optimize patient outcomes. Accordingly, primary care physicians and other health care professionals involved in the care of patients with back pain must be aware of the classification criteria for IBP and AxSpA, and they must recognize the importance of early referral to a specialist.

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AxSpA is an inflammatory disease in which the predominant symptom is back pain. In addition, many patients with AxSpA are HLA-B27 positive. As there are distinct treatment options for mechanical LBP and IBP due to AxSpA, it is critical these two diseases be distinguished as early as possible. Such accurate and timely diagnosis can limit progressive deformities of the axial skeleton and sacroiliac joints, and improve function.

Patients with AxSpA have historically experienced a gap of 5 years to 10 years between the onset of symptoms and diagnosis. Observational studies have revealed that about 12% of patients with nr-AxSpA progress to AS during a period of 2 years and about 70% develop AS in the long term. However, it is not currently possible to predict which patients will progress to AS, which will remain with nr-AxSpA, and which will experience spontaneous remission.

The reason for the delay between symptom onset and diagnosis of AxSpA is two-fold. First, until recently, the presence of radiographic sacroiliitis was a critical component to the diagnosis of AS. However, radiographic sacroiliitis can take years to develop. Because of this, the second reason for delay in diagnosis is that patients are not referred to a specialist in a timely manner. As patients with AxSpA may have an enhanced response to treatment in early years, the timely recognition of AxSpA and referral to a specialist is critical to optimize outcomes for patients.

The diagnosis of AxSpA is usually based on a combination of symptoms, physical examination, imaging, laboratory testing, and contextual factors. However, patients may present with heterogeneous features, complicating the diagnosis for clinicians. Axial spondyloarthritis should be considered in patients with chronic back pain beginning before 45 years. If the patient has evidence of sacroiliitis on radiograph or MRI, AxSpA can be diagnosed if the patient demonstrates one or more of the following features: enthesitis of the heel; uveitis; psoriasis; Crohn’s disease or ulcerative colitis; positive family history of spondyloarthritis; elevated positive CRP HLA-B27; dactylitis; or IBP.

Learning Objectives:

Upon successful completion of this educational activity, participants should be better able to assess patients with back pain.

Overview

Author(s)/Faculty: Ronald A. Codario, MD, FACP, FNLA, RPVI, CHCP

Source: Healio Rheumatology Education Lab

Type: Monograph

Articles/Items: 7

Release Date: 12/15/2015

Expiration Date: 12/15/2016

Credit Type: CME

Number of Credits: 0.25

Cost: Free

Provider: Vindico Medical Education

CME Information

Provider Statement: This continuing medical education activity is provided by