This takes less than 8 minutes to read. If you have an MCL injury, you'll find it very worthwhile.
I recently received an email from a reader, Nancy, (the email is below my answer with personal information removed) who was struggling with a few things after tearing her Medial Collateral Ligament (MCL) in her knee. I boiled them down to these:
Here are my thoughts on this.
This breaks down into a few parts: anatomy, biomechanics, and tissue healing. I'm giving a few suggestions, basics; not a comprehensive list of all of the things I would do. That's a book and I doubt any of you want to read a book today in this post. But, there's enough information here to get you on the path to recovery and to understand how these three components fit together.
Ligament is a tough, fibrous tissue with very little give or elasticity in it. It's job is to connect bone to bone and keep joints from moving more than they should. The MCL is tightest when the knee is straight which is why, usually after a Grade III tear, you end up in a brace that really doesn't let your knee move much. Also, I'm usually concerned about joint surface damage after an MCL tear because the force that it takes to tear the MCL is fairly large, what's called a high energy transfer, and that force just went through the knee. Sometimes people escape without any obvious damage but it's on my list of things to watch for. A bone bruise is another common injury with an MCL tear and you may not see that on MRI; probably wouldn't. You probably would need a bone scan to pick that up but, a bone bruise will reduce weight bearing ability and interfere with the rate of progression functionally as will damage to the articular surface.
The first part of tissue healing is a mad dash for real estate. New cells, scar, scramble around looking for a place to land. Some of these cells will land where they're supposed to, somewhere in the ligament or attached to the torn ends, and some won't. Some scar may end up on the medial meniscus or other "normal" tissue in the region. This can create trouble when you try to bend your knee later because the scar tugs on the meniscus and other tissue and it would prefer to be left alone. Result is - you hurt.
So, for the first eight weeks, roughly, scar tissue forms tethering the torn ends of the ligament and does its best to tie them together but without some guidance, which usually comes from the stress of load and motion, the result is mixed. What you have at eight weeks is sort of like a repaired bridge without all the struts and slats and bolts and some of the slats are going in the wrong direction. But. at least you have a bridge.
After the first healing phase, and there's some disagreement about the time but eight weeks is typical, is when the remodeling begins. This is when you start knocking the boards around, adding some more, shoring it up, making the bridge drivable. It may not be a very pretty bridge when you're done but if you do things right, you can drive a tank over it.
Exercise plays a crucial role in the remodeling phase and it's not just exercise at or for your knee. The knee serves at the pleasure of the hip and ankle. It goes where they go. Injuries to the knee and the subsequent decline in activity, causes atrophy of the quadriceps muscles and reflexively dials down the strength of the hip muscles. Unfortunately, much of rehab following a MCL injury is focused on muscle strengthening, of course that is important, but the tissue that needs the most help is the ligament.
Ligaments will heal best by applying controlled stress with a functional focus. The MCL does two main things for your knee: keeps the medial or inside part of the knee from opening up too (and it does this in all angles of knee flexion) and keeps the tibia from rotating too much. After about four months of work, the MCL will be close to 85% of normal strength but it takes almost a year for it to reach 100% and it's the type of movements that you use that influence the rebuilding of that strength.
Getting Your Motion Back(If something hurts, should you stop and should I push my self to get my motion back or not?)
If you've had your leg in a brace for four to eight weeks, your knee is not going to like it when you try to bend it but you have to get your motion back to be functional. Many years ago, I would force the issue and be much too aggressive. These tissues are nudged into changing their length; not pushed. Physiologic pain is not necessarily bad for you. Physiologic pain is what you feel when you tug, twist or squeeze tissue. Remember that the healed ligament is shorter than normal and you'll need to gradually lengthen it. Ligament responds best to a low load, long duration stimulus to alter its length. This is why I use the Total Gym so much (a Pilates Reformer may work in the early stages of remodeling too). I can use a low load, 20-30% of body weight, and ask you to perform a bilateral squat. You squat until you feel some pain, hold the position for about 30 seconds, and repeat. Over and over. I set a timer for 15 minutes. Do a set then move on to the next drill then come back and do another set. I often would use at least three sets and sometimes up to five.
You can also use more conventional techniques such as gently pulling your foot toward your (lie prone, use a sheet around your foot, hold onto the other ends and pull your foot) head. Again, you want to hurt a little. Hold the stretch for 30 seconds and release. Repeat this for about 15 minutes, take a break and go again.
You're not going to gain a lot of motion in a hurry though. Dense connective tissue changes slowly so expect about 10 degrees a month on average. Normal motion of the knee is about 130 degrees of motion. So, if when you start the process, you have 80 degrees, it may take five months to get the remaining motion back. Often what happens is you'll gain 20 or 30 degrees in a few weeks and then hit a very slow cycle of improvement. The temptation is to then push harder. Don't do it. Nudge your tissues. You'll have a healthier knee when you're done.
How do you know when you've pushed enough or too much? My definition of an injury is this: a transfer of energy that disrupts cellular processes leading to a decline in physical function. Pain is not an injury. If you lose motion, your muscles won't fire properly, you start limping, and these types of symptoms last for more than 72 hours, then you've injured your self. Otherwise, I usually press on (and I emphasize usually here because in most cases there's a fair amount of coaching that takes place to reduce inherent fear).
Getting Your Function Back ( Do you use a different process for strengthening the leg when you've had an MCL tear? )
The short answer is yes. As part of the remodeling process, I apply stress to the ligament and usually use a Total Gym (it also is part of getting your motion back). You lie on your side on the Total Gym (injured limb up) at a low level - Level 3 or 4. Now, perform a single leg squat through the range of motion your knee permits. The force of gravity applies a gentle gapping stress to the inside of your knee which your injured ligament restrains. Since the MCL restrains this gapping through all degrees of flexion, this drill stresses the ligament in exactly the way it's used. It gets stronger as a result of this stress. You can work on your motion (described above) as well.
As soon as possible, you want to be up on your feet stressing your leg through various functional movements. In our facility, we have tools that can alter the effect of gravity so we can perform movements such as a squat and reach across your body (the rotation stresses a different part of your ligament) that you might not be able to perform under full body weight conditions. We also use a treadmill with body weight support to allow you to walk sideways (great medial stress), backward, forward, high step, foot over foot. The idea is to blend function into the remodeling phase. You could use a pool and walk in about chest deep water. The buoyancy of the water will protect the weak tissues and the resistance will add some stress.
Balance and coordination drills become important since ligaments have receptors in them that tell your brain where your knee is at any give moment. A simple drill to challenge balance and stress the rotational element of the knee is to stand on the injured leg only and hold a weighted ball in both hands with the arms straight (something that weighs 2 to 4 lbs). Now, turn your body side to side. This creates perturbation and your foot, knee, and hip react to it. Sometimes all you need is just the weight of your arms. This may hurt some. If you're concerned about it, go back to the definition of an injury and then decide if this drill is too hard or not.
Getting Your Strength Back ( Do you use a different process for strengthening the leg when you've had an MCL tear? )
None of this recovery is linear. While you're working on your motion, you should also be working on waking your muscles up. Conventional techniques such as isometrics (quad sets, glute sets, straight leg raises, etc.) work well but are not strength building drills. Their purpose is to get the muscle to fire properly then you have to begin stressing the muscles as functionally as possible. A great way to get the hips and quads to work together is to perform a plank drill. This forces your muscles to work at a reactive level bypassing the conscious part of your brain.
The muscle fiber that seems the most difficult to recruit is the fast twitch fiber and it just happens to be the most important. You'll activate fast twitch under either of two conditions: speed or high loads. If you haven't had joint surface damage, you can load your knee in a pain free arc using a resistance that causes high levels of fatigue within 8-10 repetitions. My preference is a squatting type of drill; not a knee extension drill. This will begin recruiting fast twitch fiber. If you've had joint surface damage, you can do this eventually, but you have to go through a joint conditioning program first. You can perform squats either on a Total Gym or something comparable, a Reformer, or even upright if your able to move through the range and control the movement pattern. The key is to use enough load that your muscles start running out of gas in about 10 repetitions but that you could do 2 more. Stop when you hit 10 but could do 12. Rest one minute. Repeat this three times.
So, those are the basics. I hope this helps. And, just to make sure I've answered the top three questions:
First my MCL tear was Grade III, the radiologist suspected it was complete and diffuse, tear was at the femoral origin. The Medial retinaculum was not as well described but I understood it to be the most medial part of the retinaculum which follows the line of the MCL not the portion that merges with the rectus femoris tendon. The patella was not dislocated.
At first I was eager to start PT 2 weeks after my injury because I could tell that the immobilization had allowed the ligament to reattach. I was eager to get back muscle tone before I lost all of it. My orthopedist explained to me that would not be wise. And I realized that although the MCL would slacken with knee flexion, the medial retinaculum (MR) would not. So I continued to rest, try minimal flexion/extension heel slides and ice. I totally bought into the idea to not move into any pain. So even if that had been a good idea it is no longer and option. I continued to rest and deal with the issues and sensations that occur as muscles atrophy.
Now at 5 weeks, I have the OK to start PT and find myself confused - do I try to increase my range of motion even if it causes pain? I tried walking around, slight bending felt good without my brace but then ended up feeling at the end of the day like I had sprained my knee it hurt so much right at the MCL/MR where the original tear was. So I figure I did too much, but then for the most part it didn't hurt when I was doing everything, it hurt later when at rest...
SO on one hand I would think - if movement causes pain then I should not do it. But what I am told is that I need to work through that pain to get back range of motion. Is that true? When I read your blog on the typical exercise of trying to isolate muscles by pushing the back of the knee into a towel vs having all the muscles work in harmony you made sense. I have also been thinking about your notes on ligament healing and how the ligament is supposed to be stronger than the muscle. I also understand that at USC they are doing research on ligament/tendon healing and that eccentric not concentric work is key. Based on these thoughts does it make sense to push through pain to get range of motion and strength in a muscle back does this really strengthen the ligament or does this force the ligament to become lax and rely on the muscle to do its work? (The same way the global mobilizing muscles take over for the structural stabilizers?) If this is true then would re-strengthening take a different tack? Or would it be the same initially and then branch off...
What do you think, what would you advise?