Many articles have challenged the value of early CPM upon final impairment and functional outcomes (see references to article), but in a recent article in Physical Therapy, researchers found no significant difference in terms of clinical outcomes (e.g. extension lag) nor length of hospital stay, between patients who received:
Physical Therapy Physical Therapy plus CPM 35min/day Physical therapy plus CPM 120min/day
Some might suggest that 2 hours per day isn't long enough, and that, as we do at our hospital, 4 to 6 hours per day is what really makes a difference. There is, however, a study referenced in the article that suggests (unless I'm reading it wrong), that there is a clinical difference between patients who don't have CPM and those who have it 20 hours per day --- in that those using the CPM are more likely to have an extension lag.
A few questions: 1. How much weight do we give the results of this study?
2. What is our obligation, as doctors of physical therapy, to the patient, to the hospital, to the MD, in such a situation?
Andrew M. Ball, PT, DPT, Ph.D. Orthopedic Physical Therapy Resident Carolinas Rehabilitation
Joined: November 15, 2003
All I can suggest is that CPMs are no longer used for post-TKRs at our major hospital; they were ceased some years ago. The orthopods decided that the outcomes were the same, whether they were used for hours on end or several hours; or not used at all.
Joined: August 25, 2000
We have a copy of the article posted in the unit we are at for the MD's to look at. Since they are the ones who make the order for the application of CPM units, its up to us to show them this information and let them decide.
Joined: May 11, 2004
There might be a subgroup of patients that the CPM might be useful. Fear and anxiety weren't measured in any of the patients in any of the few studies I've read. Maybe there would be differences between a population of patients that had no fear and anxiety versus a population of patients that did have fear and anxiety associated with moving their knee.
The other thing, that study was in Canada. Their length of stay seems long compared to what most of my patients tell me. I'd say most are in the hospital 3-5 days? I don't know, I don't do inpatient. I know one current patient I have now had a 9 day LOS - but that was because she has a history of DVT and she has cardiac issues. LOS doesn't seem to be based on the amount of motion a person has but more on the DRG, doesn't it? Meaning - many times here in the States, the financial aspect is a big factor in determining LOS. Someone correct me if I'm wrong.
That particular study was only assessing the inpatient aspect - maybe there is a long term effect and a difference might be found 3 months later?
A nice thing to know about the study... since short term outcomes didn't matter, IF a hospital were short of staff in regard to PTs, well, in making patient care decisions and determining who SHOULD see a PT, the decision to toss a patient on the CPM would be an appropriate option so that the available PTs could spend time with patients that need PT care in which options other than a PT are not available.
This is really sad to say, but in my area, the one factor that I have noticed in which there is a definite difference in either motion or function (and I hate to say it) is when the patient had a home health agency involved and physical therapy in the home for 2-4 weeks. In my opinion, the patient would be FAR better off being inconvenienced and brought to me. Apparently in my area, home physical therapy involves heel slides, straight leg raises in all directions and quad sets, and then they might get to standing knee flexion and hip motions. No "quality" to the performance of the activities is worked into the program... and believe it or not, the PT's don't seem to do any manual work with the patient. There is also no gait training, so the patient hobbles in using a walker or cane with an antalgic gait with the involved extremity externally rotated - with of course extension deficits and no flexion during swing phase...
So, then, based on what seems to be the "normal" occurrence in this area - even if long term outcomes were to be measured with CPM versus no CPM, well, there would also need to be a consideration of whether there was home PT involved prior to outpatient PT.
"There might be a subgroup of patients that the CPM might be useful. Fear and anxiety weren't measured in any of the patients in any of the few studies I've read." Good point. The assumption made by virtually all researchers is a baseline of quality PT. What if the patient didn't get quality PT. Would there then be increased value in CPM?
"That particular study was only assessing the inpatient aspect - maybe there is a long term effect and a difference might be found 3 months later?" That's true about this one study, but the references point to 5 to 10 other studies that show no significant long-term difference. I've not read them all, but the ones I have read are well done studies.
"A nice thing to know about the study... since short term outcomes didn't matter, IF a hospital were short of staff in regard to PTs, well, in making patient care decisions and determining who SHOULD see a PT, the decision to toss a patient on the CPM would be an appropriate option so that the available PTs could spend time with patients that need PT care in which options other than a PT are not available." Again, a good point, but is that decision always in the hands of the PT? Often CPMs are ordered, and the PT's job isn't that of an interdependent professional (e.g. to evaluate the appropriateness of the order and refuse to comply with CPM order under specific critera), but rather that of a technician who, without much thought beyond "that's what the MD ordered" slaps on a CPM that may have no value at all. Does the rehab department have the ability to say to the ortho's, "We can serve an additional 30% of YOUR patients each day if we don't have to mess with the CPM, AND they're been shown to be pretty useless in most clinical trials. We're not going to do CPM for every patient --- regardless of orders --- only for those that we deem clinically appropriate, under specific standardized criteria."
I would agree that there are often differences in quality between the qualty of care that patients get in the average home health program, versus the average outpatient program.
Andrew M. Ball, PT, DPT, Ph.D. Orthopedic Physical Therapy Resident Carolinas Rehabilitation
[QUOTE] We're not going to do CPM for every patient --- regardless of orders --- only for those that we deem clinically appropriate, under specific standardized criteria. [/QUOTE]When you can determine and reliably apply these standardized criteria, Drew, you will be in a great position to make that sort of decision. Until then, unfortunately, it will likely be left to physician preference. RCTs like this are a a great stepping stone toward these criteria. As SJ said, fear-avoidance or some sort of kinesiophobia scale would be a great avenue to study; we know outcomes and interventions change in the low back population (George SZ, Fritz JM, Bialosky JE, Donald DA. The effect of a fear-avoidance-based physical therapy intervention for patients with acute low back pain: results of a randomized clinical trial. Spine. 2003 Dec 1;28(23):2551-60.)
I agree that many times home health provides an inadequately aggressive program for this type of patient - the general population of home health patients is older, with multiple medical problems. The (usually) PTAs that provide the majority of treatment may not feel comfortable providing the aggressive treatment these patients require. On the other hand, when I follow these patients, I often tell them that after our discharge, there is not much more to be achieved in outpatient - with a set of stairs, a sink and some weights, we can do everything they can do in outpatient (with the exception of a bike), and they don't get stuck going to rehab for another 6 weeks. But that's not really the point of this thread.
Another study that came out too recently to make it into the references in the above article:
Teeny SM, York SC, Benson C, Perdue ST. Does shortened length of hospital stay affect total knee arthroplasty rehabilitation outcomes? J Arthroplasty. 2005 Oct;20(7 Suppl 3):39-45.
One group had standard PT, including CPM, and the other had treatment which focused on mobility and faster discharge from the hospital, without CPM. There was no significant difference in outcomes at any point.
This issue really does seem to be like low back pain. Those who are fearful or have simply stopped moving due to progressive chronic pain will likely have greater benefit from CPM, while those who want to get going would probably do much better by simply getting up and moving as aggressively as they can, without being stuck in bed 20 hours a day.
Joined: May 11, 2004
Charlie, I wish you were with a HHA in my area! And you don't use a chair?!? ;) Just kidding.
Maybe a CPM wouldn't even be necessary with patients that have fear/anxiety if someone took the time to talk and explain what the movement will feel like, why it's going to feel as it does and why it's important to move the knee. And, then, put the work onto the patient, even in an inpatient situation and let the person know if they do X, you'll see them progress to a certain amount of range of motion and you'll check them twice a day to make sure they are on track. If they aren't on track and making the progress as would be expected, then toss in the CPM or if staffing allows toss in more aggressive physical therapy.
Heck, education as a whole is lacking pre-operatively, in my opinion. I forewarn every patient that I know who is heading for a total knee arthroplasty that I'd bet that the first 3-4 weeks, the idea of "why did I do this?" will pass through his/her head. I plant the seed to give the whole process 6-12 months before determining if the procedure was worth it or not. For some reason, a lot of patients believe that after the surgical procedure everything will be perfect and they'll be painfree. I don't know where that belief comes from, except many patients will voice to me that the surgeon "fixed" the knee and it is new, so it shouldn't hurt. So, technically, there may be 2 factors we have address - the false expectation of painfree status right after surgery and the potential fear/anxiety. Some of the patients I have treated really and truly believe that the new components are going to "pop" out of their knee.
How much of a financial cost is it to have CPM inpatient? Is PT involved in fitting and setting it up or does nursing?
Good point. I forgot about the chair. A nice low one, if possible, for some challenging sit-to-stand.
As far as I know, PT is responsible for setting up the CPMs. They are also generally responsible for gradually increasing the motion once or twice a day per the surgeon's order. In the Teeny study, they didn't use the CPMs specifically because they were trying to go with minimal cost.
From the billing and income standpoint, I suppose there can be value depending on the situation of the surgical hospital, supplier, third party payor, etc. Money can be made on supplies and rental (especially if the CPM goes home with the patient). That is perhaps the greatest general value I see for blindly using CPMs post-op TKA.
I recall one of the studies on CPM after TKS mentioned decreased risk of blood clot and better pain control in first few days after surgery. But functional outcome and motion were not substantially different at three months post op (it may have been longe post-op, I do not recall).
I would rather see the PT time spent on quality education for neuromuscular reeducation, normalizing gait, instruction in self-exercise, etc. I agree with Charlie Sheets and also spend as much time as possible letting the patient know the knee will be painful post-op and they may question their sanity for having the surgery in the first few weeks. I also spend time explaining the difference between 'hurt' and 'harm.'
The therapy time may be more valuable to work on the skilled needs rather than just 'get the patient out of bed.' PTs may have dug a hole for themselves in this situation over the years.
"We're not going to do CPM for every patient --- regardless of orders --- only for those that we deem clinically appropriate, under specific standardized criteria."
Sounds great - practice based on PT examination and evaluation. Isn't that what we are supposed to be doing? When this arrives, we need to get the evidence for what we do and the criteria for basing decisions easily available to all PTs.