The position of the popliteal artery in the arthritic knee

We studied the position of the popliteal artery in 32 patients with primary osteoarthritis of the knee. A total of 45 knees were studied using a nonin vasive technique with color-flow duplex scanning. The distance between the popliteal artery and the posterior tibial cortex was measured in various po sitions of flexion. The distance separating them was found to be maximal be tween 60 degrees and 90 degrees. The study was repeated in a smaller series of 17 patients (20 knees) after knee replacement but with less conclusive results. We believe the safest position on which to operate in primary arth roplasty is with the knee in flexion, but the safely margins are not the sa me in revision surgery.