In the back of the knee, there exists a small, but important ligament – the posterior cruciate ligament, or commonly, the PCL. It is one of four major bands that stretch across the knee joint, connecting the bones of the upper leg to the bones of the lower leg. In the case of the PCL, the tendon exits specifically for the purpose of attaching the femur (thigh) and the tibia (shin).
Imagine the knee ligaments as string rubber bands of ropes that connect bones and stabilize the knee joint. Each band plays a specific role in keeping the knee in tact. The PCL’s job is to keep the tibia in place and prevent it from moving too far backwards. Because of it’s location, a powerful force is required to sprain or tear this ligament and it is usually torn in conjunction with other ligament injuries or bone breaks in the knee.
So, how would one go about sustaining an injury to this ligament, especially one severe enough to require pcl reconstruction? Let’s walk through a few scenarios in order to discover some of the common ways that PCLs become strained or torn.
Examples of Injuries that require PLC reconstruction
Example #1: Elderly Patient Fall
Mrs. Johnson is 85 and still living in her own home. She does well for the most part and is still able to get around and complete simple, daily tasks. She is out front watering her flowers when she trips over a crack in the sidewalk and falls, knees first, directly onto the pavement. Her knees bend on the way down, causing direct impact to the front of the leg and knee. She calls her doctor, complaining of a stiff, swollen knee. She can still walk on it, but it’s uncomfortable enough to keep her awake at night. The MRI results show a low grade sprain to the posterior cruciate ligament. With a brace, some rest and consistent physical therapy, Mrs. Johnson is able to avoid pcl reconstruction and opt for a non-surgical method of treatment.
Example #2: Basketball Injury
Drew plays division 3 college basketball. During a game, he jumps to block a shot and gets bumped by another player, which knocks his legs out from under him. His right knee hits the floor first and he gets up from the play limping. He assumed he cannot have an injury to a knee ligament because he didn’t hear the traditional “popping” noise of a tearing ligament. But, after the game his knee is swollen and the assessment by the head athletic trainer confirms that it is indeed a knee injury - most likely a partial tear of the pcl. Drew is working with an orthopedic specialist to determine the best treatment option.
Example #3: Car Accident
Janine was recently in a car accident and fortunately, the most serious injury she sustained is a ruptured pcl that is going to require pcl reconstruction using a graft. She had been sitting in the passenger seat of the car and upon impact, her knees had flown forward into the dashboard. One knee is just badly bruised and scraped up, but the other has sustained a fracture to the knee cap and a tear to the pcl. Janine is awaiting her surgery date. In the mean time, she cannot walk without crutches because her tibia bone shifts when she moves and her knee often completely gives out.
Injuries to the pcl are not as common as other knee ligament injuries, but they do happen in situations such as the examples described above. At times, they can be difficult to diagnose an injury to this particular ligament, but once a diagnosis is made, the physician will usually classify it as a certain grade level sprain. The different levels of severity will require different types of treatment. Most partial tears can actually heal on their own with non-surgical care. IN fact even the most severe injuries, known as Grade 3 injuries, can even be treated nonoperatively because in many cases patients do not feel any functional instability. However, for patients who continue to suffer from functional pcl stability, surgical reconstruction is warranted. During this procedure, holes are drilled through the tibia and femur and a new grafted ligament is arthroscopically placed in the knee.
If you have experienced direct impact to the front of the knee and are experiencing any of the following symptoms, you may have a torn pcl:
- Stiffness and pain in the knee
- Swelling soon after the injury occurs
- Walking with a limp to make up for weakness in the knee
- Knee instability, feels as if it may "give out"