ACL Injury – Causes and Susceptibility

Day 1 – ACL Injury

My ACL injury occurred at the Indoor Soccer facility on 29th and Valmont in Boulder, CO. I made a tackle that led to the opponent falling at speed on the inside of right knee and pushing it what seemed to be 6 inches outwards and perpendicular to the normal range of motion. As well as my ACL (Anterior Cruciate Ligament) tear I also suffered tears to the MCL and LCL.

Interestingly, I didn’t feel any pain but I think I can put this down to seeing the injury occur as I fell in the tackle. Apparently the brain has the remarkable power of saving you from serious pain if it knows the injury is coming. Here’s an article about Jonathan Metz who chopped his arm off to save his own life. I heard Jonathan being interviewed and what was staggering was the remarkable lack of pain he felt when sawing through his arm – and that was attributed to the brain knowing what was coming and taking the necessary steps to protect him from pain.

As we’ll see in Anatomy of the Knee, ACL injuries can be devastating. Whereas, the MCL and LCL see sufficient blood flow to heal without surgery, the ACL does not see the same blood flow and, consequently, a torn ACL usually requires reconstructive surgery.

The ACL measures just over an inch in length and can withstand 500 pounds of pressure before failure or tearing which is not much given that normal activities apply about 100 pounds of pressure. The fact that the ACL can only withstand up to 25% of lengthening without failure in younger and healthy adults suggests that ACL tears are going to be common injuries. In fact, in the USA there are 200,000 reported ACL injuries annually (1 in 300,000 of the population.)

ACL Injury Causes

Non-contact mechanisms account for 70-80% of ACL injuries with contact injuries accounting for the remainder. The Pivot-shift is the most common form of non-contact mechanism. A pivot-shift occurs when running and then slowing down quickly while at the same time turning. The planted foot combined with the turn results in huge stresses on the knee.

Interestingly, women athletes are thought to be between 2 and 8 times more likely to suffer an ACL injury than their male counterparts. Check out my free download “Knee Pain Guide – ACL Injury Edition” for further details on why females are more susceptible together with a more in-depth analysis on the causes of ACL injury.

In my case, knowing I was a double minority (contact/male) didn’t help. As I lay on the ground a few would be doctors tried bending my knee (thanks boys). Having been helped off and sat down, I made the terrible mistake of testing the knee. I stood up only for it to crumple in several directions at once.

I was taken off to Boulder Community Hospital in surprisingly cheerful mood where my health insurance cards were scrutinized and I was finally placed on a bed awaiting inspection. Half an hour later I’d been prodded, X-rayed and manipulated (I wish I hadn’t watched that bit) and told that I likely had a torn ACL, MCL and LCL but that the good news was my PCL was probably OK. I was given painkillers, crutches a low budget leg brace and sent on my way with the name and telephone number of Dr Eric McCarty in my pocket.

It was 1230am when I got home and the last challenge of the day was to sleep with my leg elevated and iced. You try it!

Day 2 – The Road to ACL Recovery

You have to love the American healthcare system (assuming you have insurance of course). Just 12 hours after injuring my knee I’m sat in front of Dr Eric McCarty one of the world’s foremost orthopaedic surgeons. I just wish I’d remember not to look when he wiggles my leg – seeing it bend in all manner of unusual directions is nauseous to say the least.

The diagnosis needs confirming with an MRI scan but it seems the ACL, MCL and LCL are all gone and consequently the knee has zero stability.

The team at the Boulder Center for Sports Medicine help with the MRI booking which is set for tomorrow. I have to go back to see Dr McCarty the day after with the results and I’m hopeful surgery can take place shortly afterwards. At this pace I’ll be off crutches and doing proper rehab within a week or so!