This time of year, many of us migrate to the snowy ski slopes out west or up in northern Michigan, while others simply drive up the road to hit one of metro Detroit’s local ski venues (if there happens to be snow). We forgo the relaxing beach somewhere warm and opt to tackle the mountain, hill or slope on the side of a landfill. With this choice of getaways, however, comes risk. We’ve all heard of someone “blowing out” their knee. Generally speaking, this refers to the tearing of one or more ligaments inside the knee, but before we go any further, let’s learn a little more about them.
The cruciate ligaments are two ligaments that are located deep inside the knee joint and connect the thighbone (femur) to the shinbone (tibia). They are called “cruciate” ligaments because they “cross” in the middle of the knee. They are instrumental in providing the stability that is needed for proper knee joint movement and stability when you torque on your knees and put them to the test. The cruciate ligament located toward the front of the knee is the anterior cruciate ligament (ACL), and the one located toward the rear of the knee is called the posterior cruciate ligament (PCL).
The ACL prevents the shinbone from sliding forward beneath the thighbone, and it can be injured in several ways. Most often, this involves a sudden change in direction during which the knee is twisted or during direct contact, such as during a football tackle. ACL injuries are quite common in skiers, particularly if you wipe out or catch an edge with your ski. Because your ankle is rigidly immobilized in the ski boot, it’s your knee that gets twisted, and if enough force is involved, ligament or cartilage damage can result.
When you injure your ACL, you may feel or hear a pop. The knee will swell and get stiff, and you will often feel pain when you try to stand. Over time, without a functional ACL, the knee may give out, especially when you attempt to change directions. When the knee does give way, this can lead to additional cartilage damage. The “bumper cartilage” that is often damaged along with the ACL is called the meniscus.
The diagnosis of ACL injury is based on the history, a good physical exam and often, an MRI. A partial tear of the ACL may or may not require surgical treatment. A complete tear is more serious, and unfortunately, ACL tears do not heal. Complete tears, especially in younger patients, athletes and active individuals, may require surgery to restore stability to the knee. Operative treatment is most often done arthroscopically (through small poke incisions) and uses a piece of tendon, usually taken from the patient’s knee (patellar tendon or hamstring tendon) or from a cadaver (believe it or not). This tendon is passed through the inside of the joint and secured to the thighbone and shinbone with implants that are either metal or bioabsorbable. These days, there are different types of reconstructions that can be tailored based on your gender, age and activity level. Surgery is followed by a rehabilitation program designed to strengthen the muscles around the knee. Occasionally, complete tears may be treated conservatively in less active individuals or in individuals whose knees remain relatively stable despite the injury.
The posterior cruciate ligament, or PCL, is not injured as commonly as the ACL. PCL sprains usually occur when the knee is twisted or from a direct blow to the front of the knee. Without a PCL, your knee sags, and there can be increased wear and tear on the cartilage inside the knee. Like the ACL, PCL tears do not generally heal. Fortunately, many patients with PCL tears do not have as much knee instability as patients with ACL tears, and even high-level athletes can return to their sport after completing a good rehabilitation program. For patients who continue to have pain, swelling or instability of their knee, surgery may be necessary to reconstruct the PCL.
Collateral ligament injuries
The collateral ligaments are located at the inner side and outer side of the knee joint. The medial collateral ligament (MCL) connects the thighbone to the shinbone and provides stability to the inner side of the knee. The lateral collateral ligament (LCL) connects the thighbone to the other bone in the lower portion of your leg (fibula) and stabilizes the outer side. Injuries to the MCL are very common and are usually caused by contact on the outside of the knee. The LCL is rarely injured. If the MCL is torn, it does have the ability to heal. Remember the acronym RICE: rest, ice, compression (or bracing) and elevation. Most MCL tears do fine with an initial period of RICE followed by a good rehab program.
Tips for avoiding a blowout
- Have your bindings checked and make sure they release correctly.
- Stretch and warm up before your first run of the day.
- Start you downhill descent when you have a clear path that is not overcrowded.
- Start with green or blue runs and progress to the more difficult hills.
- Do not ski aggressively when you are fatigued.
- Pay attention when getting on and off the lift.
- Consider an off-season strengthening and agility program. These programs have been proven to reduce the risk of knee injuries and are offered at a number of local health clubs and training facilities.
If you happen to snowboard, your knees are “lucky,” but other parts of your body are not. Because of the binding mechanism of the snowboard, it’s harder to blow out your knee than with conventional skis. However, other injuries, such as wrist and forearm fractures, are much more common in snowboarders. If you are a snowboarder, board under control, don’t be afraid to wear wrist guards and wear a helmet.
Be safe and have fun
There you have it: the “inside scoop” on the ligaments inside your knee. So, have fun this ski season, but know your limits. Hopefully, a little knowledge and a little common sense will give you “the edge” when it comes to avoiding knee injuries this ski season.
Dr. Joseph Guettler is an orthopedic surgeon who specializes in sports medicine, as well as surgery of the knee, shoulder and elbow. He is also a proud member of the MOS team.