It seems we hear a lot about ACL tears now days. High profile athletes such as Adrian Peterson, running backs for the Minnesota Vikings, and Robert Griffin III, Quarterback for the Washington Redskins have suffered this injury and made successful comebacks.
So just what is the ACL and why does it seem to be such a common injury? The ACL is the acronym for the Anterior Cruciate Ligament (no wonder we just say ACL!) It is one of the four main ligaments of the knee. Like all ligaments, it is a tough band of tissue that connects two bones in an effort to stabilize and coordinate motion at a joint.
Specifically, the ACL connects the bottom, flat end of the femur- or thigh bone- to the top, flat end of the tibia or shinbone. By doing so it prevents the tibia from slipping forward relative to the femur, thus helping to keep the upper and lower legs in one line.
The ACL also helps the tibia resist internal rotation, or being twisted inwards. Without an intact ACL, walking becomes extremely difficult, the knee feels unstable, and motions that cause inward rotation of your lower leg, such as changing directions or planting can cause the knee to collapse under the player’s own weight.
So how does the ligament become torn? (Queasy stomachs beware!)
Any motion or force that forces the lower leg to sharply turn inward or move forward can cause an ACL rupture. It can tear if you twist your knee while keeping your foot planted on the ground, if you stop suddenly when running, if you jump and land on a extended or straight leg, or experience a direct hit to the knee.
When an ACL tears, players often report hearing or feeling a “pop” in the knee. Severe pain and significant swelling is not far behind. Then come the tears because a torn ACL means a trip to see the orthopedic surgeon.
In general, ligaments do not heal well on their own, and completely torn ACL’s generally do not heal at all. In fact, reconstructive surgery actually involves replacing the ligament altogether. To do so, surgeons typically remove a piece of muscle tendon from elsewhere in the patients body, called a “graft”, and use it to serve as a new ACL. It’s actually pretty dang amazing what these doctors can do!
Some orthopedic surgeons refer their patients to physical therapy for a short course of rehabilitation before surgery. The goals of therapy at this point are to decrease swelling, and increase range of motion and strength of your knee as much as possible.
Following surgery an athlete will work with physical therapists to slowly regain strength and range of motion as the body cements the new ACL into place. The entire rehab process usually takes between nine to twelve months.
You know the prognosis for a full recovery is good following an ACL repair when you see Adrian Peterson or RG III running and cutting up the field. As with any successful rehab of this sort, these guys undoubtedly worked amazingly hard to get back to where they are today. They are great examples that show that even after a devastating injury such as an ACL tear, athletes, with the help of amazing surgeons, and dedicated therapists can and do get back to action!