Looking at both the Frobell and Hurd studies, the first thing to understand is that the information collected was of ACL injured athletes who have injured their ACL for the very first time. Patients who had a previous ACL injury to either knee were excluded; so unfortunately, we don’t know how successful one would be if they chose a nonoperative pathway for their second (or third, or fourth) ACL injury.
Age is a very important consideration, and looking at the strongest of the studies, the Frobell study, they only looked at ACL injured patients who were aged between 18-35 years of age (mean age 26). Meaning that care needs to be taken when applying this information to younger, skeletally immature patients, and older ACL injured patients. The Hurd paper extended their data collection to ACL injured patients aged between 13 years and 57 years of age (mean age 27yrs), but one must keep in mind the methodological quality of this paper wasn’t as sound as the Frobell studies.
More often than not, other knee injuries occur at the same time of ACL injury; for example, meniscus tears, bone bruises, MCL injuries. Other types of knee injuries were a consideration in who were included in these studies and who weren’t.
In the Frobell study, they included patients who also had minor/mild meniscus tears that would not affect rehabilitation due to restricted ROM bracing, grade 1-2 injuries to MCL/LCL/PCL injuries and those knees that already had mild OA changes or mild cartilage damage. However, they did exclude patients who had complex meniscus tears that needed extensive repair and protected weightbearing for many weeks following surgery, full thickness cartilage injuries to the knee and grade 3 injuries to the MCL and LCL. The Hurd paper had similar inclusion/exclusion criteria.
Lastly, it appears from the ACL-injured patients included in these 2 studies is that care needs to be taken when interpreting the findings of these studies to professional athletes; as professional athletes were not included in the data collection.
As much as I think professional athletes should be given every opportunity to attempt nonoperative rehab; and the work from Myklebust et al 2003, and the case of the professional EPL player returning to play at 8 weeks following ACL injury and continuing to play at least 18monts later (Weiler et al, 2015) will certainly justify this; the thing to understand about professional sport is that it is a completely different beast to non-professional sport.
So many external variables weigh into the decision-making process when it comes to the paid professional athlete; age, playing position, how many years they have left in the game, time in the season, and how long into their playing contract they are. Do they have any 1-2 year goals like play in a World Cup? These are just some examples of other decisions that need to be made when dealing with a professional athlete. It is a very difficult decision to make, and I commend any athlete and medical/rehab/high performance staff for giving a nonoperative plan a red-hot go!
In summary, based on high-quality research, nonoperative management of ACL injuries is a really viable option for some ACL injured patients.
Generally speaking, patients aged over 18, even those who are participating in pivoting sports like soccer/netball/basketball, who have injured their ACL for the first time, who may also have minor injuries to other parts of the knee, can be offered nonoperative ACL management knowing that the long term outcomes (at least 5 years down the track) will be similar to those who have had an early or delayed ACL reconstruction.
At this stage however, we can’t guarantee successful short term and long term outcomes with nonoperative ACL management (as compared to ACLR) in skeletally immature athletes, professional athletes and those that have high grade injuries to other structures of the knee at the time of their ACL injury.
As always, sound clinical reasoning and shared decision-making with the patient needs to applied to each ACL case, and ACL injuries and rehabilitation options should never be managed with a “one-size-fits-all” approach.
Frobell et al (2013) – Treatment for acute anterior cruciate ligament tear: five year outcome of a randomised trial. BMJ. 2013 Jan 24;346:f232
Hurd et al (2008) - A 10-year prospective trial of a patient management algorithm and screening examination for highly active individuals with anterior cruciate ligament injury: Part 1, Am J Sports Med. 2008 Jan;36(1):40-7.
Mylebust et al (2003) - Clinical, functional, and radiologic outcome in team handball players 6 to 11 years after anterior cruciate ligament injury: a follow-up study. Am J Sports Med. 2003 Nov-Dec;31(6):981-9
Weiler et al (2015) - Non-operative management of a complete anterior cruciate ligament injury in an English Premier League football player with return to play in less than 8 weeks: applying common sense in the absence of evidence. BMJ Case Rep. 2015 Apr 26;2015