Sonographic evaluation of femoral condylar cartilage in osteoarthritis and rheumatoid arthritis.

Employing a real-time sonographic scanner with a 5 MHz linear probe, the articular cartilage of the knee was studied in four groups of subjects: normal subjects aged 18-36 years and 50-63 years, patients with rheumatoid arthritis (RA) and patients with osteoarthritis (OA). Cartilage thickness was diminished both in RA and in OA knees compared to the two groups of normal joints, even if in RA the reduction was less. The cartilage surface appeared irregular more frequently in OA than in RA. Our survey suggests that the sonographic technique is a useful, non-invasive diagnostic method to study the articular cartilage of the knee.