What has the Biggest Impact on Outcomes Following ACL Reconstruction Surgery?
May 21, 2012 
25 Comments
It is no surprise that loss of motion is one of the biggest factors in patient satisfaction following ACL reconstruction surgery, specifically loss of knee extension. In addition to the limitations in functional activities that occur with loss of knee extension, we have also discussed some of the risk factors of loss of motion following ACL reconstruction.
Loss of knee extension has a dramatic impact on gait, muscle activity, and normal tibiofemoral and patellofemoral arthrokinematics.
Imagine not being able to straighten your knee out. You can’t lock out your knee for stability. You naturally will shift your weight to the other extremity and overload your other knee, hip, and probably even your back. Your quad and hamstring never get to shut off and relax. Your patellar tendon will probably be on fire, and your patella will always be engaged and taking stress.
I can definitely see why patient satisfaction would be poor if you had long term loss of motion following ACL reconstruction!
Impact of Loss of Motion on the Development of Arthritis
In addition to poor patient satisfaction, recent research has shown that loss of motion following ACL reconstruction also results in the development of osteoarthritis. In a recent study in AJSM, Shelbourne et al followed 780 patients for a mean of over 10 years. They showed that of the group of patients that had normal motion on follow up examination, 29% exhibited signs of osteoarthritis on radiographs. Conversely, 47% of the group that showed loss of motion had developed osteoarthritis.
This makes perfect sense as your arthrokinematics, center of rotation of the joint, and tibiofemoral and patellofemoral contact pressure will be altered.
How Much Loss of Extension is Significant?
More importantly, the authors also showed that even a loss of 3-5 degrees of motion had a significant impact on both patient satisfaction and the development of early arthritis. Those subjectives that exhibited greater than a 5 degree loss of motion had an even more dramatic impact.
According to DeCarlo and Sell, the average amount of knee extension in healthy individuals is 5 degrees of hyperextension, with 95% of individuals demonstrating some amount of hyperextension in the knee.
Taking this into consideration, we should challenge the common belief that 0 degrees of knee extension is “normal.” Individuals with 5 degrees of knee hyperextension that only restored their knee to 0 degrees of extension after ACL reconstruction surgery have a significantly greater chance of developing early osteoarthritis.
Clinical Implications
Based on these recent studies, there are bunch of clinical implications that we should all consider. Here are just a few that I thought of right away:
- Timing of ACL reconstruction surgery and pre-operative rehabilitation is important to settle down the knee, reduce swelling, and most importantly restore range of motion.
- Knee extension should be restored as soon as possible after surgery, and should be one of the focuses of the initial postoperative phase
- Even a small 3-5 degree loss of either extension of flexion range of motion has a significant impact
- Most patients will have a certain degree of hyperextension, restoring a person to 0 degrees of knee extension is likely not enough
- For those training post-ACL rehab clients, keep this in mind if the individual does not have full motion. Advancing to exercises with high tibiofemoral and patellofemoral compressive and sheer forces before achieving full knee motion should be performed with caution.
- Each patient should be assessed individually and range of motion should be restored to their unique assessment
In regard to what to do with the tight person, I’ll work on a future post that discusses how I assess and treat loss of knee extension range of motion, but in the meantime I would love to hear what you think about this information and what you do with these patients.
Great post Mike! That’s why ther ex is not enough and manual treatments, plus assessment is important. Especially to get back the PROM which is supposed to be greater than, and not equal to AROM.
Exactly, the couple of articles in the past that have shown home exercises are equally as effective as skilled therapy following ACL reconstruction have many flaws. I think this is a great point Erson, thx!
just what % of post ACL pt’s reach the pre-injury ROM beyond 0 degrees of extension. Isn’t there a self limiting reflex response of the individual not to go into the “red zone” so to speak, of challenging the ACL’s tautness. It seems that it is common to be 5 degrees less ( 0 degrees) than an uninvolved knee that is +5 degrees
Joel, although it seems common to have a loss of motion, that doesn’t necessarily mean it is best! I personally haven’t had this self limited reflex you mention. I bet the key is to:
1) do everything you can so you dont lose the motion and then have to aggressively restore and trigger that “reflex”
2) Gradually, but progressively get that motion back
If you take your time getting there, perhaps that prevents that self limitation.
Great post, Mike…couldn’t agree more. I might add that restoring quad activation/NM control has proven to be just as essential. Restoring normalized ROM is the 1st step…while assuring the patient has adequate control of the newly gained ROM is a close 2nd. If they don’t have the quad control…chances are they won’t be able to control TKE at midstance and thus resorting back to a flexed gait.
Coming back from an ACL myself I have found it regaining the flexibility in my Hip Flexors, Glutes and Quads has helped me get flexion similar to my healthy leg.
I also Asked my PT the reason they stopped my extension at 0deg and his reasoning was that working towards hyperextension( beyond 0 will affect the tightness of the graft. Have You heard that too?
I had my first job in physical therapy working for Dr. Richard Steadman in Vail, Colorado…basically the ACL capital of the world. Extension is always goal #1, meant to be achieved immediately post op. Goal #2 is being able achieve full extension with a quad isometric contraction. If your unaffected knee hyper-extends 5 degrees then you post-op knee needs to get to 5 degrees of hyper-extension. Your quad needs to be strong enough to actively extend to it’s fully extended position (+5 degrees).
A high percentage of my clientele continues to be post-op ACL patients, and hardly anyone has an issue regaining full extension (and subsequently a very successful outcome) due to proper pt education. I give each patient of mine a list of 4 goals that MUST be achieved by 6 weeks, which is the typical ‘healing phase’ post ACL.
1. Full Extension
2. Perfect quad set/able to do SLR without ANY lag–TONS of repetitions as pt progresses, try to make every rep perfect.
3. Flexion to at least 120 degrees. 120 typically comes within the first 10-14 days, the remaining flexion returns very easily.
4. Reduce pain, swelling, inflammation. Urging people to not over-do their activity, not taking stairs normally for 4-6 wks, ice and elevate regularly, etc. Swelling is the biggest enemy, it inhibits your quad, limits your ROM, and leads to all the issues pt’s have post-op.
Getting the patient started on the right foot paves the way for a successful outcome. Of course post-op ACL pt’s fear hyper-extending their knee, but ACL pre-hab, and post-op PT within 3-5 days helps get good quad control early on, and pt’s benefit greatly from that.
Mike i am training a college football lineman this summer who had Acl/Lcl reconstruction and meniscal repair an achilles allograft acl and semi-tendonosis lcl allograft. He has another 5 deg to reach 0 ext and his flexion is just over 90 deg. His school trainer told me to do all closed chain exercises along with the at home brace he wears at night and progress him as i see fit. Mike does the multiple surgeries change the ext/flex restoration time frame. Or should the rehab be more agressive. Any help would be greatly apreciated thanks
Yes, definitely changes many factors. Try searching pubmed, you should find several papers that address this.
Question – isn’t knee hyperextension often a compensation for poor ankle mobility in dorsiflexion? I’d be concerned about working towards hyperextension in the affected leg unless I had evaluated the unaffected leg for limitations in dorsiflexion first. I’m a S&C coach, not a PT, so my understand of this is limited! Please let me know your thoughts.
Sure, but one could argue chicken or the egg. To me, I have seen many collagen lax people that have a lot of recurvatum. Think about it, if they are loose and sit back in knee extension, how could they dorsiflex their foot? The stand in a certain degree of plantar flexion. I would say that is more common but heck anything is possible. I dont see a lot of people with tight DF that causes excessive hyperextension of the knee. They probably had that hyperextension to begin with.
Thank you! That makes sense. Those darn chickens and their eggs.
Hey Mike great post. What do you think about using a theraband looped underneath the heel to force the knee into a little hyper-extension while performing a quad set 2-3 weeks after surgery?
Chris, if that isn’t too dynamic that sounds fine. You do need to have a little bit of caution of forced hyperextension beyond what is “normal” (See above) for the patient, as this could strain the ACL.
I try to prevent the loss of motion as much as possible so that I dont have to force it too much.
Great post Mike. but after surgery, shouldn’t the knee be in a recovery state without too much stress or weight on it for an amount of time. The constant slight bend and straightening of the knee should support the knee’s abilty to be moved without the fear of immobilization of the knee. which tools should be used in the extension recovery stage of the knee?
In regard to tools, that will be in next week’s post!
Sometimes some stress is needed to facilitate a healthy process.
Hi Mike
I am currently 3 weeks post op for a revision ACL using the patellar tendon graft after I unfortunately tore my 2.5 year old hamstring graft. My recovery is going well and I have full extension and I get close to 1cm lift off heel to floor while laying down and contracting my quads hard. My unaffected leg (and the operated side pre injury) have a lot of hyperextension, probably 5cm lift. Should I be aiming for equality here? My PT and Surgeon of course get the final word but I am very interested to hear your thoughts on how much hyperextension should be limited in this kind of case.
Hi mike, I’m 45 and snapped my acl and high grade tear of my mcl playing netball. I did not have good rom prior to surgery. Extension wasnt measured but my knee was definitely off the ground, and my flexion was only about 80 after a pt session. I had recon 5 weeks after the initial injury and I am now 5 days post op. I still have heaps of.pain. I am doing all the physio exercises but am worried about my Rom. I have been lying on the couch reading everything I can but everything says u should have normal Rom prior to surgery for a positive outcome. I’d appreciate any advice. I’m really concerned. Thanks Kylie.
Hey Mike, I had multiple ligament surgery in November 2008 (acl, mcl and lcl- allografts were used for all).
By September 2010 I was 8 degrees from 0 exstention on my right leg and had about 140 degrees flexion as compared to my left leg that has 5 degrees hyperexstention and 155 degrees flexion.
Now, in November 2010 I retore my acl and just recently (July 31st 2012) I decided to get the acl surgery done (allograft again). So now I am 8 weeks post op and I have been able to get 0 degrees exstention in my right leg and about 145-147 degrees flexion in my right leg. Is there any way I can make my exstention and flexion in my right equal to my left? Or is that not a possibility because of all the surgeries I have had…and build up of scar tissue?
Any advice would be appreciated.
Jesse, the longer it is from surgery, the harder it is to achieve, but sounds like you are doing much better after the 2nd time around. You may stil benefit from some skilled manual therapy. Good luck.
Hello Mike,
Somewhat embarrased to ask but its been 18 months since my ACL surgery and yet I can’t get full extension. Sometimes i feel like theres something in my knee blocking it from full extension. Is it possible that there may be fluid in my knee? I sometimes have a friend put his weight on my knee to force it down. Is that a good idea? Any exercises that may help me get full extension. Any advise is much appreciated.
Hard to diagnose over the internet, see a physical therapist
Had your ACL reconstructed?
I am doing a Master’s reseach project on ACL reconstruction and want to know about your experiences about rehabilitation, and getting back in the game.
Please visit http://fluidsurveys.com/s/returntosport/ to participate in a short web survey. Participation involves answering 19 on-line questions about your activity level, your experience surrounding the process of rehabilitation after ACL reconstruction, and your decisions surrounding returning to sport. The questionnaire will take 5-10 minutes to complete, is completely anonymous, and will have no influence on your medical care. This study has received approval from Hamilton Integrated Research Ethics Board.
Jacquie Minnes PT
School of Rehabilitation Science
McMaster University