ACL Injuries In The General Population

Since I was on the topic of ACL injuries in the adolescent female last week, I thought I might broaden my scope a little and cover some more ground on ACL injury. This time I'm going to look more generally at the rates of ACL injury, how many people actually return back to sport after an ACL reconstruction (ACLR), patello-femoral joint (PFJ) pain during rehabilitation, and some return to sport (RTS) outcome measures that should a "non-negotiable" when deciding on return to play.

As I covered earlier this week, a case study performed on 242 patients - all under the age of 18 years-old - who underwent primary ACLR, found that 75 (30%) had sustained another injury to their surgical graft, or to their opposite ACL, or both within 15 years of having the primary surgery performed. Taking a wider look across an older age group it appears that as we get older, the success of primary ACLR is marginally better. A systematic review and meta-analysis of 1004 patients (mean age 30 years, 66% male) found that within 2 years of primary ACLR, 13.5% had failed. Another review found that 12% of primary ACLR will fail at least 10 years follow-up.

Key message - surgery is not 100% successful. The key period of rehab is obviously the first 12 months post-operatively, but on-going regular strength and conditioning (2-3 x per week) is essential whilst the person is still playing sport.

In regards to RTS, the number of people that RTS following ACLR is really surprising. One study in particular found that 81% of people will return to any sport, 65% had returned to pre-injury level of sport, and only 55% of people had returned back to competitive sport. In a study by the same authors, they found that less than 50% of people went back to competitive sport within 2-7 years following ACLR.

Key message - be realistic with your patient/athlete that there is a high chance that they won't return to their pre-injury or competitive level of play after their ACLR. And that is totally OK. Life, work and family often take priority. Do encourage modified exercise options though, for on-going general health and well-being.

Following on from this, in regards to actual clearance from the medical team to RTS, it is very surprising to read that only 13% of 264 studies on ACLR used objective outcome measures to decide if a person was ready to RTS! Even more worrying was that 40% of the studies did not report any outcome measures, and 32% of the studies found that patients were being cleared to RTS based purely on post-operative time frames! (reference). With this information, it is no wonder why we have such high re-injury rates!! Of course, clinical tests carried out by the treating orthopedic surgeon are of absolute importance - ie. absence of swelling, full knee AROM, negative Lachman's test and a negative pivot-shift test - but I think a marriage of both clinical tests and functional tests are essential before the athlete returns to play. I have provided a link to a paper that provides a very clear criterion-based progression from ACLR through to RTS, and I feel that we should all be using this model (or one very similar to it) with all of our ACLR patients/athletes.

Key message: Use objective measures to determine if your patient is ready to RTS! Don't just assume that they are ready to RTS after 12 months.

Lastly, and this is one particular area that I feel very strongly about, so forgive me in advance if I get a little bit "ranty", but PFJ pain should not be viewed as "collateral damage"  during ACLR, particularly during the first 1-2 months post-op. I've seen one too many patients advised to push through the pain, only for them to have a very slow recovery and poor overall outcome. In my opinion, PFJ pain is a sign that rehab has been inadequate and the VMO, glut medius and the hamstrings on the operated leg still need A LOT of work.

There has been some very interesting research performed on the incidence of PFJ osteoarthritis (OA) in patients who have undergone ACLR. The first study found that PFJ OA (on X-Ray) was present in 34 of 70 patients (47%!!) within 5-10 years following ACLR. What is even more concerning, another study found that PFJ OA (on MRI) was found in 19 of the 111 patients (17%) at 1-year follow-up, with men 6x more likely to have PFJ OA compared to women! These MRI findings were absent in uninjured controls.

Key message: Neglect the PFJ at your patients peril!! #KnowPainKnowGain.

That will do for today! I hope you get something out of this summary of information. As always, please feel free to comment if you think that I have missed something, and as always, please share this post with people that you think would like to read it.

Have a great week!