Ultrasound evaluation of the popliteal space. Comparison with arthrography and physical examination.

Ultrasound scanning techniques were used to examine the popliteal space in 102 knees. In 30 of 34 knees in which arthrograms were also obtained, the information obtained from both tests was the same. In two instances in which there were different results, the presence of palpable popliteal cysts was confirmed by ultrasound scans but not by arthrography, and in two other cases, small asymptomatic cysts were seen on arthrograms but not on ultrasound scans. In the 68 other knees, ultrasound scans were helpful in the differential diagnosis of popliteal cysts, popliteal artery aneurysms, thrombophlebitis, and a solid poplitieal mass. The results indicate that ultrasound scanning is a valuable, rapid, safe, accurate technique in evaluating patients with symptoms or findings related to the popliteal space.