Osteoarthritis Differential Diagnoses

Updated: Oct 10, 2017
  • Author: Carlos J Lozada, MD; Chief Editor: Herbert S Diamond, MD  more...
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DDx

Diagnostic ConsiderationsRheumatoid arthritisOther arthritides

The initial diagnostic goal is to differentiate osteoarthritis from other arthritides, such as rheumatoid arthritis. The history and physical examination findings are usually sufficient to diagnose osteoarthritis. Radiographic findings confirm the initial impression (see Workup), and laboratory values are typically within the reference range.

Rheumatoid arthritis predominantly affects the wrists, as well as the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints. It rarely, if ever, involves the distal interphalangeal (DIP) joints or the lumbosacral spine.

Rheumatoid arthritis is associated with prominent, prolonged (>1 hour) morning stiffness and overtly swollen, warm joints. Radiographic findings include bone erosion (eg, periarticular osteopenia or marginal erosions of bone) rather than formation. Laboratory findings that further differentiate rheumatoid arthritis from osteoarthritis include the following:

  • Systemic inflammation (elevated erythrocyte sedimentation rate [ESR] or C-reactive protein [CRP] level)
  • Positive serologies (rheumatoid factor [RF] or anti–cyclic citrullinated peptide [anti-CCP] antibodies)
  • Inflammatory joint fluid with a predominance of polymorphonuclear leukocytes (PMNs)
  • Elevated white blood cell (WBC) count

Back pain may result from spondyloarthropathy or from osteoarthritis with sacroiliac and lumbosacral spine involvement. Clinical history and characteristic radiographic findings can be used to differentiate these disorders.

Secondary osteoarthritis must be considered in individuals with any of the following:

  • Chondrocalcinosis
  • History of joint trauma
  • Metabolic bone disorders
  • Hypermobility syndromes
  • Neuropathic diseases

The following disorders should also be considered in the differential diagnosis:

  • Crystalline arthropathies (ie, gout and pseudogout)
  • Inflammatory arthritis (eg, rheumatoid arthritis)
  • Seronegative spondyloarthropathies (eg, psoriatic arthritis and reactive arthritis)
  • Septic arthritis or postinfectious arthropathy
  • Fibromyalgia
  • Tendonitis

In patients with knee pain, other disorders to consider in the differential diagnosis are patellofemoral syndrome and prepatellar bursitis.

Differential Diagnoses