Intra-articular pressures during arthroscopic knee surgery.

Arthroscopic surgery of the knee requires effective joint distention. No reports exist in the literature relating to optimal fluid pressure and dynamics of joint distention during arthroscopic knee surgery. Static and dynamic laboratory studies were performed on a knee model to establish an accurate method of measuring pressures from the arthroscopic cannula. A prospective study of 107 subjects who underwent arthroscopic surgery by one surgeon (J.W.E.) was then performed using saline distention from a saline bag wrapped with a pneumatic cuff. Intra-articular pressures ranged from 0 to 750 mm Hg, but usually fell into the zone from 70 to 120 mm Hg. A minimum pressure of 30 mm Hg was required for visualization. Variations in pressure magnitudes as well as flow rates during the procedures were studied. Technical suggestions based upon these data include maintenance of pressure between 70 and 100 mm Hg; avoidance of abrupt changes in position of the distended knee; and maintenance of lower pressure levels (35-50 mm Hg) if the synovium has been violated as in the performance of a lateral release procedure.