Multicompartmental pressures in the knee joint during arthroscopy.

It is well known that fast changes of position of the knee joint cause high instantaneous intraarticular pressures. During arthroscopy, rotation and flexion of the leg can create a closed-off compartment, increasing the risk of capsular rupture. To evaluate the risk of compartmentation, a study has been conducted in which the intraarticular pressure in 12 knee joints of three women and nine men was measured with Myopress catheters (ATOS Medical AB, Hörby, Sweden) located in the suprapatellar pouch, and the anteromedial and the posteromedial recesses during arthroscopy. This study showed that a starting pressure of 100 mm Hg causes a significantly higher peak pressure than does 75 mm Hg. The pressure varies simultaneously in all compartments without signs of local compartmentation in any position of the joint within the range of 0-90 degrees of flexion. With a positive pressure in the knee joint, no compartmentation occurs within the suprapatellar pouch or anteromedial posteromedial compartments during an arthroscopic procedure.