The knee joint is composed of at least two bones joined together by ligaments. Known as the largest joint in the body, the knees anatomy is composed of three separate sections:
- The femur, otherwise known as the lower portion of the thigh bone.
- The tibia, otherwise known as the upper portion of the shin bone.
- The patella, also known as the kneecap.
The femur, tibia, and patella all fit together with the femur and tibia held together by the thick bands of tissue known as ligaments. These ligaments help to keep the knee joint together and stable. The muscles located along the front of the thigh, known as the quadriceps, help keep the knee strong.
There are two cruciate ligaments, which are the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL). The PCL ligament is located behind the knee and controls the back-and-forth motion of the knee. The PCL is tougher than the ACL and so is less often injured. When the posterior cruciate ligament is either sprained or torn, it is known as a posterior cruciate ligament injury. This type of injury can occur to anyone, but they’re especially common among skiers and athletes who play baseball, football, or soccer. PCL injuries are far less common than ACL tears. In fact, PCL injuries make up less than 20% of all knee ligament injuries. Most commonly, PCL tears happen with other ligament injuries. Isolated PCL tears are even less common.
Causes & Symptoms
A PCL injury is a sprain or tear of the posterior cruciate ligament. A direct blow to the knee can injure your PCL. For instance, the PCL can be injured in a car crash when your bent knee hits the dashboard. You can hurt your PCL while doing certain activities if you fall on your bent knee with your foot or toes bent downward or if the front of your knee is hit. A PCL injury can also occur if you stretch or straighten your knee beyond its regular limits (hyperextension of the knee).
A posterior cruciate ligament injury can cause mild, moderate, or severe damage. Healthcare providers rate this condition in four separate categories, such as described below:
- Grade 1 – A partial tear is presented in the ligament.
- Grade 2 – There may be a partial tear and the ligament feels loose.
- Grade 3 – The ligament is completely torn, and the knee is unstable.
- Grade 4 – The posterior cruciate ligament is severely injured, and another knee ligament is also damaged.
People who have injured the posterior cruciate ligament of the knee often report a combination of the following symptoms:
- Stiffness – Swelling may cause the knee to become stiff. An individual may have trouble bending the knee, resulting in a limp or difficulty going up the stairs.
- Swelling – Bleeding around the torn ligament may result in swelling. Swelling typically occurs within 2 or 3 hours prior to the injury.
- Knee instability – Mild or moderate sprains may cause very little or no knee instability, while more severe sprains may cause a person to feel as if the knee is about to buckle or give out. In some cases, knee instability is a sign of an undiagnosed PCL tear that occurred months or even years earlier.
- Sharp pain around the knee – This can happen immediately or develop in the hours or days after the injury.
- Trouble bearing weight – The injured knee may be difficult or painful to stand or walk on, especially for long periods of time.
- Tenderness – The knee joint, particularly the back of the knee, may be tender or sensitive to touch.
- Tingling and numbness – In more severe PCL injuries, people may report the feeling of tingling or numbness around the knee joint.
Unlike causes of an anterior cruciate ligament injury, PCL injuries are not always accompanied by a popping sound at the time of injury. Depending on the severity of the injury, some people may not notice a PCL tear, especially if the injury is mild. In addition, the PCL is often injured in conjunction with other structures in the knee, such as the ACL or meniscus. These injuries may cause additional symptoms, such as knee locking or bruising, and may require additional treatments.
Who gets Posterior Cruciate Ligament (PCL) Injury?
While posterior cruciate ligament injuries can occur to anyone, there are certain risk factors that place people at high risk of this condition include:
- Sports – People who participate in contact sports are at higher risk of injuring the PCL. Contact sports often involve quick and sudden changes of direction, such as soccer, football, or basketball. People who participate in non-contact sports, such as dance or skiing, are also at higher risk for a PCL injury.
- Age – PCL injuries are most commonly seen in ages between 20-40 years, however, older adults are more prone to ligament injury due to general wear and tear.
- Motor vehicle accidents – Also known as a “dashboard injury” happens when a driver’s or passenger’s bent knee slams against the dashboard, pushing in the shinbone just below the knee and causing the posterior cruciate ligament to tear.
- Manual labour – Certain manual labour jobs, such as construction work and other jobs that require regularly squatting and lifting heavy objects, increase the risk of a PCL tear.
How Does it Affect You? How Serious is it?
In severe cases of PCL injuries, you might have longer-term knee pain and instability if the injury is left untreated. You may also be at risk of permanent disability if the injury was caused by a complete rupture. Additionally, there can be a possibility that arthritis can develop in your affected knee.
If a PCL has been torn completely, surgery can be done when other treatment methods have not helped. It may also be done in patients whose PCL is no longer connected to the bone. Although problems are rare, all procedures include some risks. Some of the following complications are:
- Problems with anesthesia, such as wheezing or sore throat.
- The need for more surgery.
- Excess bleeding.
- Blood clots.
- Permanent knee instability.
Recommended Treatment & Rehabilitation
During a diagnosis of posterior cruciate ligament injuries, your doctor may press on your knee to feel for any injury, looseness, or fluid in the joint from bleeding. He or she may move your knee, leg, or foot in different directions and ask you to stand and walk. Your doctor will then compare your injured leg with the healthy one to look for any sagging or abnormal movement in the knee. Afterwards, they may request additional imaging tests to help determine the extent of the damage. Certain tests include the following:
- Arthroscopy – If it’s unclear how extensive your knee injury is, your doctor might use a surgical technique called arthroscopy to look inside your knee joint. A small video camera is inserted into your knee joint through a small incision. The doctor then views images of the inside of the joint on a computer monitor to check for any results.
- X-ray – While an X-ray cannot find ligament damage, it can reveal bone fractures. Patients with PCL injuries sometimes have breaks in which a small chunk of bone, attached to the ligament, pulls away from the main bone.
- Magnetic Resonance Imaging (MRI) – This procedure uses radio waves and a magnetic field to create computer images of the soft tissues of your body. An MRI scan can clearly show a posterior cruciate ligament tear and determine if other knee ligaments or cartilage also are injured.
If your PCL injury is severe, surgery might be required to reconstruct the ligament. Surgery might also be considered if you have persistent episodes of knee instability despite appropriate rehabilitation.
Based on evaluation, a physiotherapist will be able to develop a customized treatment program to ensure a safe return to your desired activities. Whether or not you have surgery, this program may include:
- Patient education – Your physiotherapist will educate you about your posterior cruciate ligament injury to help you better understand the recovery process within this type of injury. They will work with you to identify and suggest changes or improvements to activities or factors causing your pain, such as the type and amount of exercises you perform, your daily and athletic activities, or your footwear.
- Range-of-motion exercises – Limited mobility or restriction of your knee, hip, or ankle can cause increased stress on your knee. Your physiotherapist may teach you self-stretching techniques to help decrease tension and restore normal motion of the lower extremity joints, from the pelvis / hip region down to the foot.
- Pain management – Your physiotherapist will design a program to help address your pain, including applying ice to the affected area. They may also recommend modifying some activities that cause pain.
- Manual therapy – Your physiotherapist may treat your PCL injury using hands-on therapy to gently move your muscles and joints. These techniques help improve motion. Through manual therapy, your physiotherapist can help guide your knee and lower extremity into a less stressful movement pattern.
- Supporting equipment – Your physiotherapist or healthcare providers will recommend using braces, walking aids, wraps, or tape to strongly assist in your PCL recovery.
- Muscle strengthening – Muscle weakness or imbalances can contribute to knee ligament conditions and symptoms. Your physiotherapist will design a very safe, personalized, and progressive resistance program for you based on your PCL injury level. This program likely will include exercises for your core and lower extremity.
- Functional training – Once your pain, strength, and motion improve your health overall, you will need to safely transition back into more demanding activities in order to regain full strength. It is important to learn safe, controlled movements to minimize stress on your knee. Based on your movement goals, your physiotherapist will design a series of activities to help you learn how to use and move your body correctly and safely.
Below are a few exercise examples you to try to reduce symptoms associated with posterior cruciate ligament injury:
Begin by sitting with your affected leg straight and supported on the floor or a firm bed. Next, place a small, rolled-up towel under your knee. Your other leg should be bent, with that foot flat on the floor. Tighten the thigh muscles of your affected leg by pressing the back of your knee down into the towel. Hold for about 5-6 seconds, then rest for 10 seconds before repeating 8-12 times a day.
Knee flexion with heel slide
Lie on your back with your knees bent, then slide your heel back by bending your affected knee as far as you can. Hook your other foot around your ankle to help pull your heel even farther back. Hold this position for 5 seconds, then rest for 10 seconds. Repeat this method 8-10 times a day.
Straight-leg raises to the back
Lie on your stomach and lift your affected leg straight up behind you. Lift your toes about 15 centimeters off the floor while holding this stretch for 6 seconds afterward. Finally, lower your leg slowly, repeating 8-12 times a day.
Alternative & Homeopathic Treatment
Most cases of posterior cruciate ligament injuries can be treated without the need for surgery – some of these homeopathic treatments include:
- I.C.E. – Rest, icing, compression, and elevation may be advised to help reduce the initial symptoms of knee pain. This protocol will be particularly important if the symptoms are manifesting for the first time.
- Non-steroidal anti-inflammatory drugs (NSAIDs) – Over-the-counter or prescribed anti-inflammatory medications can help reduce inflammation and swelling due to posterior knee pain.
- Shoe inserts – Wearing shoe inserts may benefit a subset of individuals with abnormal foot structure or movement patterns while running.
- Ginger or turmeric – Both herbs are known for their anti-inflammatory properties. Moreover, some studies have found them to be comparable in effectiveness to ibuprofen, a commonly used NSAID.