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ACL, PCL, & Other Knee Abbreviations

By Alan Williams, PT, OTR/L, ATC, CSCS

Outside it was a cold February evening, but inside the small, noisy confines of the racquetball court, it was like a sauna. I was playing a friendly match with some buddies, and I’m not one to brag, but at the tender age of 34, I was quite good. The serve was off, and as I stepped to take a swing, it happened – I felt the sickening sensation of the two main bones of my knee (the femur and tibia) separate by an incredible distance and slam back together. Pain tore through my knee and I collapsed. Although I knew I had experienced major knee trauma, tests revealed it was worse than expected. I had torn my ACL, MCL, lateral meniscus, and medial meniscus. Two surgeries and nine months later, I was back on my feet, but it was a full two years before I really felt 100% again.

Unfortunately, knee injuries such as I experienced are an all too common occurrence, not just among athletes, but the elderly, the obese, and anyone who engages in regular bending and twisting as part of a job or hobby (such as manual labor, gardening, dancing, etc.) runs the risk of tearing a tendon or ligament in their knee. Because the knee is one of the most complicated joints in the body, it’s helpful to learn about its basic structure so you can better protect yourself from serious injury.

There are four primary ligaments that connect your femur to your tibia and fibula, providing support and stabilization during movement. The anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) form an “X” across middle of the knee, while the medial collateral ligament (MCL) and the lateral collateral ligament (LCL) reside on the inside and outside of the joint respectively. In addition, you have two primary tendons – the quadriceps tendon (connecting your quad muscle to your kneecap) and the patellar tendon (connecting the kneecap to the tibia). Last but not least are the meniscus, the C-shaped pockets of cartilage which provide cushion for your knee.

It sounds complicated, and it’s easy to get overwhelmed thinking about everything that goes on in your knee. Each of these components work together to give you a fully-functioning joint without you even having to think about it, but it’s important to remember that even a body part as well-designed as the knee is not invincible. Preventing injury takes a few simple, but deliberate efforts.

The first and most important step is to reduce your risk. While there are some things that make you susceptible to ligament and tendon tears that cannot be helped – the elderly are at risk due to degenerative changes in the knee; females are at greater risk than males due to the Q-angle (the inward angle the female knee must adopt after puberty due to widening of the pelvis) – but many other risk factors can be reduced or even eliminated. This includes losing excess weight, building flexibility, wearing proper protective gear during high-risk sports (such as football and soccer), and maintaining a healthy diet.

Another very important aspect of preventing injury is to keep the strength of your leg muscles balanced. For example, if your quadriceps (front thigh muscle) is stronger than your hamstring (back thigh muscle), the quad will naturally pull the femur forward, and the weaker hamstring will not be able to adequately stabilize. A knee that is not stabilized is more vulnerable to injury. Your physical therapist will be able to suggest specific ways to participate in balanced strength training.

Sometimes even the best preventative measures are not always enough, and knee injuries do happen. But chin up! Medical advances have shortened what used to be a year-long recovery into a now typical 2-3 month timeframe. So be conscientious when participating in your favorite activities, but don’t let the fear of a knee injury stop you from getting out there.

Don’t let knee pain hold you back. Call 463-0022 today for your FREE Knee Pain Assessment!