Discharge Instructions: Using a Continuous Passive Motion (CPM) Machine

Your healthcare provider prescribed a continuous passive motion (CPM) machine to use after surgery. The CPM machine is attached to a knee or other limb on which the surgery was done. While you relax, the machine constantly moves the knee or other limb through a range of motion for a period of time. CPM is thought to prevent joint stiffness, relieve pain, and help regain normal motion. The CPM has supportive padding, a power supply, and a frame that adjusts to your body. Here’s what you need to know about home care.

Home care

Recommendations for home care include: 

  • Use the machine settings and make any adjustments as directed by your healthcare provider.

  • Call your provider when you think you can stop using the machine completely. This is usually when your arm or leg can reach an extended (straight) position and when you can bend your arm or leg to the degree your provider advised.

  • Use pain medicine as directed by your provider.

  • Follow any special instructions given to you by your provider. If you feel pain, stop the exercise. If the pain continues after stopping, call your provider.

  • If your provider has advised you to work with a physical therapist (PT), continue to do so. CPM does not take the place of working with a PT. A PT can help you with exercises.

Call 911

Call 911 right away if you have:

  • Chest pain

  • Shortness of breath

When to call your healthcare provider

Call your healthcare provider if any of these occur:

  • More pain in the affected limb

  • Pain that doesn't get better with medicine

  • Pain or swelling in the area near your surgery

  • More redness or any fluid leaking around the incision

  • Numbness, tingling, or blue-gray color in your affected limb

  • Fever of 100.4°F (38°C) or higher, or as directed by your healthcare provider

  • Chills