Kaplan Diagnostic A Practice Test

The key idea is to keep the knee’s motion within what the surgeon ordered after a total knee arthroplasty. Continuous passive motion (CPM) is used to promote range of motion without active muscle use, but the amount of flexion or extension the device imposes must stay within the prescribed limits to protect the new joint and surrounding tissues. Flexing the knee to 90 degrees five hours after surgery is typically beyond the initial postoperative range and could risk prosthesis strain or tissue injury, so this observation requires nursing intervention to adjust the device to the ordered ROM or pause it until further orders are obtained. In contrast, extending the leg a small amount (about 10°) with CPM is generally acceptable, the drain amount of 75 mL in the early hours post-op can be expected, and using the nonoperative leg to reposition onto a bedpan is common when weight bearing is restricted.