What is the most appropriate rate of motion for a continuous passive motion machine after a total knee arthroplasty?

The most appropriate rate of motion for a continuous passive motion (CPM) machine after a total knee arthroplasty is typically around 2 cycles per minute. This slower rate is beneficial for several reasons. It allows for adequate joint range of motion while minimizing discomfort and the risk of over-stressing the healing tissues.

The primary goal of using a CPM machine post-surgery is to gently promote joint mobility and prevent stiffness without causing excessive strain on the healing knee. At a rate of 2 cycles per minute, the motion remains slow and controlled, which helps facilitate circulation and addresses potential complications such as deep vein thrombosis.

Faster rates, such as those at 4, 6, or 8 cycles per minute, may not provide the same level of gentle mobilization, potentially leading to increased pain or injury, particularly in the early stages of recovery when the tissues are still vulnerable. Therefore, the choice of 2 cycles per minute aligns with optimal patient care principles following total knee arthroplasty.