Sports Medicine Research: In the Lab & In the Field: Physical Function After an ACL Injury With and Without a Reconstruction (Sports Med Res)


Friday, October 11, 2013

Physical Function After an ACL Injury With and Without a Reconstruction

Lower extremity performance following ACL rehabilitation in the KANON-trial: impact of reconstruction and predictive value at 2 and 5 years

Ericsson YB, Roos EM, and Frobell RB. Br J Sports Med. 2013; 47: 980-985.

Take Home Message: A patient with an anterior cruciate ligament (ACL) rupture will regain muscle strength and the ability to perform functional movements regardless of whether or not the ACL is reconstructed.

Despite nonsurgical treatment options, ACL reconstruction (ACLR) is the standard of care following an ACL rupture. Interestingly, the effect of ACLR on the muscle strength and functionality is not well understood. Therefore, Ericsson and colleagues completed a prospective cohort study to (1) compare muscle strength and functional performance after a standard rehabilitation protocol between patients with and without an ACLR. They also assessed if muscle strength and functional performance predict patient-reported outcomes at 2 and 5 years after injury or a delayed ACLR among patients that did not immediately receive an ACLR. This study was an ancillary study of the KANON trial, which is the only randomized controlled trial to directly compare both traditional ACLR and an optional delayed ACLR. The authors included 45 patients who had undergone ACLR within 10 weeks of injury (single bundle, patellar tendon or hamstring tendon grafts, performed by 1 of 4 senior surgeons) and 42 patients who were initially treated nonsurgically (23 patients went on to receive an ACLR at 31 to 244 weeks post injury). All patients completed a goal-oriented rehabilitation program, supervised by a single physical therapist. Following completion of all rehabilitation goals (~ 37 weeks post-injury) patients completed tests for muscle strength and functionality. All tests were completed using both the injured and uninjured sides. Tests performed were quadriceps and hamstring strength tests, 1-legged hop test, square hop test, vertical hop test, one-leg rise test, and closed eye one-legged balance test. The authors reported the tests results for each leg and in terms of the limb symmetry index (injured leg results/non-injured leg results x 100) with ≥ 90% defined as satisfactory. All patients also completed the Knee Injury and Osteoarthritis Outcome Score to assess subjective pain and function at 2 and 5 years post injury. Overall, there were no major differences in muscle strength or functional performance between the 2 groups. Performance of the vertical hop test and one-leg rise test were predictors of the need for delayed ACLR over 5 years and subjective pain and function at 2 and 5 years, respectively.

Overall, these results are intriguing because it highlights that we must be vigilant to always understand how our treatment decisions impact the patient in terms of time spent rehabilitating as well as the long-term implications on the patients overall health. The results presented here suggest that patients with and without an ACLR may have similar muscular strength and ability to perform functional movements at ~37 weeks post injury. Also interesting, is the concept that researchers may have found 2 tests (one-leg rise and vertical hop test) which clinicians could use to identify patients who may need an ACLR  in the future, although more research is needed to verify this. Another intriguing concept that stems from this research is that perhaps the decision to undergo nonsurgical treatment would actually decrease the amount of time between injury and return to participation for at least some patients. While this is an inviting idea, more research must be completed to understand the long-term impact this will have on the joint. It would also be ideal in this situation to have a screening tool to decipher which patients respond best to this treatment. In conclusion, despite no strength or functional differences between patients with and without an early ACLR the vertical hop test may be a good clinical indicator of if the patient may need a delayed ACLR.

Questions for Discussion: Do you currently consider or counsel your patients on the potential merits of nonsurgical treatment of ACL injuries? If so, what indicators, if any, do you look or test for to see if the patient may respond favorably?

Written by: Kyle Harris
Reviewed by: Jeffrey Driban

Related Posts:

Ericsson YB, Roos EM, & Frobell RB (2013). Lower extremity performance following ACL rehabilitation in the KANON-trial: impact of reconstruction and predictive value at 2 and 5 years. British Journal of Sports Medicine, 47 (15), 980-5 PMID: 24029859


Joseph Ayres said...

This shows that patients who tear their ACL may be able to return to play sooner if they forgo the reconstruction surgery. However, what are the implications for the future? This says that about 37 weeks post injury, and even years post injury patients with and without the surgery had similar strength and functional movement. But what would happen if the patient ceased to be active? Would it be necessary to continue activity in order to maintain stability in the knee? In this case, would it then be necessary for all patients who forgo the ACL reconstruction surgery to have it once they become inactive?

Kyle said...


Excellent inquiry. Unfortunately, the answer is not so clear. While this study shows similarities between both cohorts, some interesting literature exists to suggest that it may come down to the individual and their ability to stabilize the knee joint. These patients may either be able to stabilize the joint, or fail to do so resulting in episodes of "giving away." In the literature these patients are identified as copers or noncopers. In a randomized controlled-trial being done by Richard Frobell and colleagues (Frobell RB, Roos HP, Roos EM, et al. Treatment for acute anterior cruciate ligament tear: five year outcome of randomized trial) patients first attempt to forgo reconstruction. Then, if they cannot manually stabilize the knee undergo surgery. This seems to be one of the best options as identifying patients as copers or noncopers immediately after injury is extremely difficult. I think the answer to many of your questions about future outcomes for these patients are still unknown as many studies have not yet followed patients long enough to have a firm understanding of this issue.

Anonymous said...

I think advising for or against non-surgical treatment depends on the severity of the injury. Many ACL injuries have accompanying meniscal or MCL injuries. I believe that an isolated ACL tear would respond better to non-surgical treatment compared to an ACL tear with additional joint injuries. Also, the patient's reported pain level and stability I think are good indicators for who would be a candidate for immediate surgery and who would be better suited to delayed reconstruction or non-surgical treatment.
In response to an earlier post about activity level, if the person becomes less active is it possible that their knee would become more stable? They may not become completely inactive but may modify their activity to avoid positions or sports that recreate instability.

Kyle said...


Thanks for the comment. You bring up some excellent points. I agree that the severity of the injury (e.g., cocomitant injuries). The thing that seems to be most apparent though is in fact the patient's self-reported level of stability. In my above comment this is what is known as copers and noncopers in the literature. Some literature has embraced a 3rd group known as adapters which again you indicated in your post. This group are comprised of individuals who change their level of activity to remain somewhat active but mitigate the episodes of giving away. This will depend on the person's current level of activity at the time of injury and their desired future level of activity (i.e., elite level athletes may not be good candidates for this due to the high demand on the joint and the need to return to their elite level of activity).

Kaitlyn Johnson said...

Even though more research needs to be done, I think this is an interesting topic to look into. I have seen athletes with ACL injuries who get surgery and are out for a while. So it’s interesting to think of just doing treatment and rehab with these athletes and not having them get surgery. This would create a faster return to play time; however I can also see how it would affect long-term. I can also see what others have said about how other injures like MCL or meniscal can accompany ACL tear. I think further research would be interesting to see happen and what would be the outcomes.

Jenna Robinson said...

I agree with Kaitlyn, I think that this was a very interesting topic but I would also be curios to see if females would have a harder time recovering without ACLR because of their weaker vmo.

Marisa Rizzo said...

This is very interesting to me because it is so common to have surgery done when you tear your ACL. I had always thought that the best way to go is to have it reconstructed, especially an athlete. I think this is very interesting to know that a rehab program can give you the same results with out the surgery and even return you to play faster!

Will Bradley said...

Do you think you would see any differences if the results if ACLR patients had allografts instead of patellar tendon or hamstring tendon grafts?

Kyle said...

Kaitlyn, Jenna and Marissa,

Wonderful comments. Thank you! I enjoy this particular question immensely. I think what we need to keep in mind though is that the decision to remain ACL deficient is multifactoral. First and foremost, the athlete's age and future level of competition needs to be surveyed. Many recreational athletes may be able to cope sufficiently or even adapt their level of activity to limit knee instability. If the athlete is at a high level or may reach a highly competitive level reconstruction may be advised to ensure the stability under the stress of competition. There is also so interesting literature suggesting that patients may try to remain ACL deficient and if instability remains, seek late reconstruction with minimal risk to the joint. It should also be disclosed though that this was only within 5 years of surgery which is a relatively short time period to understand the long-term effect on the joint. I believe this is the most exciting option out there. Waiting for the body to respond to the deficiency and then treating the patient based off of that. Have any of you considered this as an option? Might you consider this with future patients? Why or why not?

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