Continuous Passive Motion After Surgery

What is continuous passive motion?

A continuous passive motion (CPM) machine helps your child move their joint after surgery. Your child might use this device for their knee, hip, shoulder, or elbow. The CPM machine gently moves the joint. Your child does not have to exert any effort. The machine does all the work. It can be used while relaxing, eating, or sleeping.

It is important to keep joints moving after surgery. This helps reduce stiffness and pain.

Range of motion refers to the ability to move a joint fully. If your child does not move their joint soon after surgery, they may not regain their full range of motion.

How CPM works

Swelling is common in the first 24 hours after surgery. A CPM machine helps move fluid away from the joint. This reduces blood and fluid build-up in and around the joint.
If your child does not move their joint soon after surgery, scar tissue can form. CPM therapy after surgery increases the chance that your child will be able to move their limb fully.

How to use the CPM machine

CPM therapy will begin right after surgery. It is important that you and your child understand how to use the machine. Your child’s therapist may adjust the device to fit them before surgery. The therapist will give instructions on how to use the device.

The CPM is set to run for a fixed amount of time. The therapist will set the machine to a certain range of motion. Generally, the therapist will increase the range of motion a little each day. Your child will need to use the CPM machine for about 6 weeks after surgery.

To learn more about how a CPM device works or how your child should use it, talk to your health care team.

Find more information on Rehabilitation Services.