MCL Sprain/Tear RTP
If you had to pick something to go wrong with your knee, an MCL sprain would be a damn fine choice. That’s lucky, because an MCL sprain is the most common knee injury among the general American population. If you want the nitty-gritty, your MCL (Medial Collateral Ligament) is a flat band that runs down the inside of your knee. It serves to hold the femur and tibia in place so as to stabilize the knee joint. Without the MCL, your knee would be all loosey-goosey, as the doctors say. So it’s decided… the MCL is a good thing to have.
In the NFL, we see tons of MCL injuries. In fact, we see far more than what I actually catalog in database. (Some specifics on my database and charts can be found here.) It’s not that MCL injuries go unreported, it’s just that teams often don’t provide enough details for us at how to know exactly what is wrong with a player’s knee. A good deal of injuries reported simply as, “knee injury,” are probably MCL sprains. I log those vague knee injuries, but I don’t file them as MCL injuries. Same goes for injuries called, “knee sprains.” Almost all of those are specifically MCL sprains, but again, I don’t log them as anything more than, “knee sprains.” I try to keep my database pretty clean, so if I’m logging something as an MCL sprain, I need to be pretty confident I’m correct. That means I miss plenty of injuries like this where the team simply never specifies the details.
Also, I should note that MCL sprains are a good example of when you should take my RTP chart with a grain of salt. In my, “About Injury Estimates,” section, I mention that because my focus is on players who actually miss games, I often overlook players who suffer an injury but miss zero games. Knee and ankle (low ankle, not high ankle) sprains are a great example of this. While my chart above indicates that only 14% of the players with MCL sprains missed zero games, that’s almost certainly skewed. That number should be higher. I have taken steps to make sure I’m doing everything within my power to capture that lower end of the rehab spectrum, but it is still difficult and some players who miss zero time do slip past me. I highlight this issue in my general sprain/strain overview page here.
In the NFL, MCL sprains commonly occur as a result of two different situations. When a player’s cleats are fully “dug in,” and gripping the turf, any pressure, force, or hit to the outside edge of the knee can cause an MCL injury. This is common along NFL offensive linemen, especially when blocking a defensive lineman. The MCL can also be damaged by a direct hit, such as from a tackling defender’s helmet, to the outside of the knee. Basically, something in the knee has to give on a huge hit directly to the knee, and because of how the knee is built, that force from the outside edge often stresses the MCL the most. In cases like this, a player is fortunate not to suffer other knee ligament damage (such as an ACL or meniscus tear). The severity of the MCL tear increases the likelihood of other accompanying knee ligament damage.
As with all sprains, MCL sprains are divided into three categories. Grade I sprains indicate minor, often microscopic ligament tears. Grade II sprains indicate partial ligament tearing, but not enough to compromise the structural integrity of the knee. Grade III sprains indicate a full tear or rupture. The good news is that MCL sprains rarely require surgery. Grade I and II are almost exclusively treated through rest and rehab. The MCL receives good blood supply, and, left alone, it will heal itself with time. Grade III MCL sprains are a little tricky. It used to be that doctors typically called for surgical repair for Grade III MCL sprains, but these days that is declining. Currently, if the damage is limited solely to the MCL, surgery is rare. If there is accompanying damage, often with the ACL, then the surgical route is still common. Among Grade III MCL sprains in the general population, up to 78% of the patients have ACL damage, and up to 25% have meniscus damage.
Currently, the NFL media estimates for MCL sprain return to play orbit around, “two to four weeks.” They’ll go with less if it’s confirmed as a Grade I sprain, and more if it’s a Grade III sprain. According to my data, we’re all in the same ballpark. If I had to throw some numbers out there, I’d say a good guess would be anywhere from zero to four weeks missed. This becomes much easier if the team gives some specifics. I’d say we’re looking at zero to two weeks missed for a Grade I MCL Sprain, two to four weeks missed for a Grade II MCL sprain, and at least five weeks for a Grade III MCL sprain (assuming no other knee ligament damage).
