What is a CPM (Continuous Passive Motion) Machine?
After hip arthroscopy surgery you may be prescribed a Continuous Passive Motion (CPM) device to use at home. Although the device may look intimidating at first, it is actually easy to operate. Originally designed for patients undergoing total knee replacements, the CPM device has been found to also help with pain and motion after other surgeries including hip arthroscopy. It is designed to gently flex and extend the leg to prevent scar tissue formation in the front of the hip and help with pain. Many patients find using it is very comfortable and even relaxing.
A study done at Duke University in 2017 found that patients who were prescribed a CPM device after hip arthroscopy had less pain at 6 weeks and greater improvement in hip function than patients who did not receive a CPM machine (1). Another study in 2021 found patients who used a CPM used less narcotic pain medication than those who did not (2).
In some cases a CPM device is not necessary. Your surgeon and their staff will instruct you on if and how to use the device after surgery.
Cunningham, Daniel et al. Continuous Passive Motion after Hip Arthroscopy for Femoroacetabular Impingement: A Prospective, Comparative Trial. Arthroscopy, Volume 33, Issue 6, e17 - e18
Munsch M, Vajapey SP, Vasileff WK, Ellis T, DeWitt J, Ryan J. Use of continuous passive motion device after arthroscopic hip surgery decreases post-operative pain: A randomized controlled trial. J Clin Orthop Trauma. 2021 Oct 18;23:101646.