Total Joint Replacement Educational Series Part 14: What is a Continuous Passive Motion (CPM) Machine?

WHAT IS A CONTINUOUS PASSIVE MOTION (CPM) MACHINE?

A motion machine will be used post-operatively to improve your range of motion more quickly and to make you feel more comfortable following the knee replacement surgery.  Even with the less invasive procedure, the healing of your incision can cause scar tissue to form, which causes your tissues to be stiffer than normal tissue.  The use of the CPM machine after your total knee replacement guides tissue growth, increases motion and helps reduce stiffness.  Your new joint also likes to be moved so this motion machine can make you feel more comfortable too!

You can use the CPM machine based on your comfort level, and it can be used as much or as little as you would like to use it.  We recommend that you use the CPM machine at least two times daily for one to three hours at a time.

WHAT TO EXPECT...

• The Day of Surgery

A CPM machine will be set up on your bed.  The motion will be set to full straightening with an initial bending of up to 90 degrees.  Even when you are resting, the CPM machine will work your knee!

• Post-op Days One to Three

Your bending will be increased based on how much bending you achieve in physical therapy.  In general, the bending will be increased by 10 degrees more than achieved during your last exercise session.  The goal will be for you to achieve 110 degrees or more of bending.  A portable CPM machine also will follow you to home.