Q&A Time! Continuous Passive Motion After ACL Repair? | Modern Manual Therapy Blog

Q&A Time! Continuous Passive Motion After ACL Repair?

A blog reader recently emailed me with the following question.
"All of my Post Op ACL repairs have recently showed up with CPM, are you aware of any literature that shows it's effectiveness?"

Thanks for reading and your question! After a quick search, every link I could find was basically either written by an ortho group or a vendor who sells CPM. No research for ACLs that I could find. If it's anything like TKA, I'm sure it would be similar to these findings.


It sounds as if the local surgeon's group had a nice dinner with some CPM salespeople. Tell your patients there does not seem to be any benefit.

Are any of you out there who treat post op regularly seeing this or aware of any literature saying CPMs are useful for anything other than causing pain and fear avoidance?

Here are my thoughts on CPM use after ACL reconstruction (and they are actually the same for all other knee surgeries, including TKA):

Annoying to use - they are cumbersome and typically can only be used in bed

Inconvenient to use - who in their right mind thinks that telling someone to lay down for 4-8 hours a day is reasonable &/or productive.  I would like to see 1 surgeon actually do this before they tell their patients to do it

Expensive – sometimes insurances don’t cover them (can’t blame them for not covering them because the research shows they’re not effective).  The only thing guaranteed with CPMs is that your medical costs will increase

Highly inaccurate – I don’t think I’ve had one patient in over 10 years have the degree number on the CPM correlate to their actual knee flexion.  Just this past week I had a 17 yo patient who had ACL reconstruction with meniscal repair say their CPM was up to 114° and their actual passive knee flexion was 68°

Ineffective - according to the research on CPM after ACL reconstruction, the CPM provided no significant differences in ROM and pain (the two things it is most commonly prescribed for) – link to the research article.

Surgeons who prescribe CPMs do make me look good because I get to be the one who tells the patient to stop wasting their time using the CPM and instantly I have a new friend (in the patient that is).  I now have the patient on my side.  I then proceed to show them what they should do instead – which is at least 100 wall slides a day (this is for patients who have less than 100 ° flexion).  And please don’t confuse wall slides with wall squats, that would not be good.  Measure the patient’s knee flexion before and after 25 wall slides and I bet it will show an improvement – 3 minutes of that has now given the patient more ROM than 6 hours of a CPM.

Interested in live cases where I apply this approach and integrate it with pain science, manual therapy, repeated motions, IASTM, with emphasis on patient education? Check out Modern Manual Therapy!

Keeping it Eclectic...


Post a Comment