Arthritis may, at times, present a mystifying appearance to the radiologist. However, even complex cases will usually yield to a logical and systematic approach. My personal approach involves consideration of each of the following five principles in turn:

  1. Sutton's law

  2. Radiographic hallmarks

  3. Pattern approach

  4. Demographics

  5. The law of parsimony

I find it helpful to separately consider the arthropathies that affect the appendicular and axial skeleton. In the next two sections, I will apply each of the five principles above to these two categories of arthritis.