A torn anterior cruciate ligament (ACL) is usually severe enough that there’s no mistaking it. If your knee suffers an audible pop, is excruciating to place weight on, or swells to where you can’t bend or straighten it, see a doctor immediately.
“You don’t want to wait too long, because if you try to walk around like that for a couple months with a bent knee, that really starts affecting other parts of your body,” said Tony Rocklin, director of physical therapy at Therapeutic Associates in Portland, Oregon.
The ACL is one of the main ligaments that help stabilize the knee. It mainly prevents your shin bone (tibia) from moving too far forward on your thigh bone (femur) during traumas such as hyperextensions and knee buckling in or out too far. Strong and smart muscles from your hip to your foot assist in keeping the knee stable and decreasing stress to your ACL.
Sports like skiing, tennis, or basketball are common culprits for ACL injuries. Jerky movements, in which the knee must rotate on a dime, are usual suspects for this injury. Even more severe are impact traumas from sports like football.
There's a distinction between different levels of ACL sprains. Minor sprains are generally candidates for non-surgical treatment, depending on lifestyle. However, if you tear your ACL, chances are good you’ll need to hit the operating table.
“Depending on the physical therapist and the surgeon, you’re back to work within a week or two," said Rocklin. "But to get back to competition can take anywhere between six to nine months—for some even longer."
Before you despair at the length of recovery, know that there are some recovery exercises you can learn in physical therapy and do at home to help restore range of motion and strengthen the area, and that many factors can affect whether or not you need surgery.
Some tips on prevention: as always with the knees, keep the gluteus muscles, quadriceps, calves, hamstrings, and hip flexors strong. When working out, don’t focus on the numbers; instead, make sure your technique is tuned so that your reflexes follow suit.
A 2005 study revealed that ACL injuries might be genetic. To keep the odds stacked in your favor, try to keep your hips in line—especially when falling—so that hyperextension and over-rotation are minimized.