The American College of Rheumatology and
other groups have developed criteria for diagnosing
OA in the knee, hip, and hand; however, diagnosis
is challenged by the limitations of X-ray findings in
the early stages of OA and the fact that such findings
do not correlate well with clinical symptoms.
For example, estimates of the prevalence of knee OA
vary widely according to whether clinical or radio-graphic criteria are used and the characteristics of
the cohort studied.
Computed tomography and magnetic resonance imaging can more readily detect
cartilage and bony changes, but criteria for defining
OA using them have not yet been established