Accuracy of pressure and flow capacities of four arthroscopic fluid management systems

PURPOSE: The present study was conducted to evaluate 4 different fluid delivery systems: Arthrex AR-6450, Stryker 1.5L High Flow Pump, Arthro FMS 4, and Acufex InteliJet. Their flow and pressure capacity, as specified by the manufacturer, and their accuracy, as measured in a standardized fashion, were compared with directly measured pressure values. TYPE OF STUDY: Experimental study. METHODS: Two experiments were performed: (1) the achieved pressure was measured with the pressure sensor within a ball and compared with the preset pressure values. The pressure was increased constantly while the flow was kept constant. (2) maximum flow per minute was tested using a beaker and a stopwatch. RESULTS: The highest measured pressures for the Arthrex and the Stryker pumps were 115 mm Hg (46% of published maximum pressure) and 113 mm Hg (57% of published maximum pressure), respectively. The highest measured pressures for the Arthro FMS 4 and the InteliJet pumps were 251 mm Hg (101% of published pressure) and 132 mm Hg (88% of published maximum pressure), respectively. The maximal flow values for the Arthrex and Stryker pumps were 900 mL/min (56.3%) and 675 mL/min (48%), respectively. The Arthro FMS 4 and InteliJet pumps reached a maximal flow of 450 mL/min (56%) and 1,250 mL/min (62.5%). CONCLUSIONS: In the simpler pumps (Arthrex AR-6450 and Stryker 1.5L High Flow Pump), the pressure on the display must be set to higher values compared with the outflow-controlling pumps (Arthro FMS 4 and InteliJet) to achieve the same intra-articular pressure. All pumps were able to maintain a pressure of 60 mm Hg very accurately. Therefore, a surgeon can trust all of the pumps when the pressure is set below 60 mm Hg.