Osteoarthritis Initiative (OAI) Study Protocol

General Inclusion Criteria:

• Men and women ages 45 – 79
• With, or at risk for, symptomatic femoral-tibial knee OA
• All ethnic minorities (focus on African-Americans)

Major Exclusion Criteria:

• Inflammatory arthritis (RA)
• Contraindication to 3T MRI
• Bilateral end-stage knee OA

The Protocol and Appendices are available for download:

Progression Cohort:

Symptomatic Tibial-Femoral Knee OA (1,389 -- 29%), presence of BOTH osteophytes and frequent symptoms in 1 or both knees:

• Definite Tibial - Femoral osteophyte (OARSI atlas grade 1-3) at baseline (clinic interpretation)
• Symptoms: Pain, aching or stiffness on most days of a month in past year

Incidence Cohort

No Symptomatic Tibial-Femoral OA in either knee (3,285 -- 68%), at increased risk for symptomatic OA in 1 or both knees:

• Frequent knee symptoms without x-ray OA
• May have osteophytes in one or both knees, but not osteophytes and frequent symptoms in the same knee
• Two or more other eligibility risk factors

Control Cohort

No Symptoms AND No Radiographic Tibial-Femoral or Patello-Femoral OA in either knee, No Risk Factors (122 -- 3%)

Schedule of Assessments