Diagnosis
Osteoarthritis is typically diagnosed on the basis of clinical and radiographic evidence.
Imaging Studies
- Plain Radiography - The imaging method of choice because radiographs are cost-effective and can be readily and quickly obtained; in the load-bearing areas, radiographs can depict joint-space loss, as well as subchondral bony sclerosis and cyst formation.
- Computed Tomography (CT) Scanning - Rarely used in the diagnosis of primary osteoarthritis; however, it may be used in the diagnosis of malalignment of the patellofemoral joint or of the foot and ankle joints.
- Magnetic Resonance Imaging (MRI) - Not necessary in most patients with osteoarthritis unless additional pathology amenable to surgical repair is suspected; unlike radiography, MRI can directly visualize articular cartilage and other joint tissues (e.g., meniscus, tendon, muscle, or effusion).
- Ultrasonography - No role in the routine clinical assessment of patients with osteoarthritis; however, it is being investigated as a tool for monitoring cartilage degeneration, and it can be used for guided injections of joints not easily accessed without imaging.
- Bone Scanning - May be helpful in the early diagnosis of osteoarthritis of the hand; bone scans also can help differentiate osteoarthritis from osteomyelitis, bone metastases, and metabolic bone diseases.
Differential Diagnoses
- Avascular Necrosis
- Fibromyalgia
- Gout and Pseudogout
- Ankylosing Spondylitis Imaging
- Imaging in Neuropathic Arthropathy (Charcot Joint)
- Lyme Disease
- Patellofemoral Arthritis
- Psoriatic Arthritis
- Rheumatoid Arthritis (RA)