The posterior cruciate ligament (PCL) connects the femur (thighbone) to the tibia (shinbone). Located deep inside the knee and behind the joint, it's about 2 inches long and works to limit backward motion of the tibia. Violently twisting or overextending the knee can cause the PCL to tear, leaving the knee unstable and potentially unable to support the person's weight. As the knee's strongest ligament, the PCL usually won't tear unless there's a powerful blow to the knee, such as when the shin or knee strikes the dashboard during a car accident. Because of this association with a physically traumatic event, PCL tears are often accompanied by injuries to other knee ligaments. Some people tear the PCL when playing rugby, football or other contact sports, but this is relatively rare.
Our approach to PCL tears
UCSF is committed to helping patients with PCL tears return to the highest level of activity possible, whether that means a daily walk or reporting for practice with the NFL. Our team includes orthopedic surgeons, primary care sports medicine doctors, physical therapists and athletic trainers. These specialists work together to tailor a treatment plan to each patient's needs and goals.
We treat most simple PCL tears with physical therapy and, if helpful, a brace. In addition to providing information and education on the injury, UCSF offers the full range of physical therapies, including specifically designed exercise regimens, functional activity training and neuromuscular reeducation (techniques that condition the area to move normally again).
If the injury is severe or accompanied by damage to other knee ligaments, we may recommend reconstructive surgery.
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Signs & symptoms
PCL tears have a variety of symptoms, but the most obvious are knee pain, swelling and instability.
A thorough exam may be difficult if your knee is very swollen, but certain tests can help clarify what's wrong. In the "posterior drawer test," the doctor pushes the shin back while the knee is bent 90 degrees. If the tibia gives more than 5 millimeters, the PCL is likely torn. Your doctor may also perform other tests to help determine whether the ligament is fully torn, partially torn or simply sprained.
In addition, your doctor may use certain imaging tests to examine your injury more closely, including:
- X-rays. These may be ordered to make sure there are no fractured bones in your knee.
- Magnetic resonance imaging (MRI). With an accuracy rate of nearly 90 percent, MRI is an effective tool for determining whether the PCL is torn and, if so, the extent of the damage. It will also provide information on the other knee ligaments and the meniscus (knee cartilage).
Simple PCL tears are usually treated with physical therapy rather than surgery. A brace may be used at first, and a well-designed physical therapy program helps you regain function and stability. The time it takes you to recover will depend on your injury's severity; full recovery ranges from a few weeks to a few months.
Surgery is often considered if additional ligaments are torn or if you haven't regained knee stability after completing physical therapy. The decision to have surgery is often a personal choice, in which you and your doctor consider factors such as your age, physical condition and athletic goals.
The usual surgery is a minimally invasive procedure in which a surgeon reconstructs your PCL using a graft from another part of your body (an autograft) or a cadaver (an allograft). The graft serves as scaffolding for the ligament to grow new tissue; the type of graft used is based on patient and surgeon preference.
Taking less than two hours, the surgery is done with an arthroscope (an endoscope for use in joints), through small incisions made around the knee. A tiny camera is inserted to allow the surgeon to see all of the knee's structures and to appropriately position the new ligament. You'll be under general anesthesia (completely asleep) and will also be given a nerve block, an injection that interrupts pain signals in the area and lessens post-op pain.
Most patients return home on the same day and use crutches and a knee brace for at least six weeks. One to two weeks after surgery, the stitches are removed and a physical therapy program is started. Committing to the program is key to achieving a full recovery.
Frequently asked questions
- When can I shower after surgery?
You need to keep your dressing on and knee dry until your first post-op visit, usually one to two weeks after surgery. At that point, you'll likely be cleared to shower. But you'll need to wait three to four weeks from your surgery day before submerging your knee in a bathtub or swimming pool.
- When should I start physical therapy?
It's best to start as soon as possible after surgery, generally within the first one to two weeks.
- How long will I be on crutches?
Most patients use crutches for about six weeks, though the time varies depending on your precise injury and how quickly you heal.
- Do cold therapy devices provide good pain relief?
You have a number of icing options, including applying regular ice packs and even packages of frozen vegetables. Cold therapy machines are convenient and effective, as well as somewhat expensive.
- Will I have stitches?
You'll have two or three stitches, covered by a bandage. They will be removed one to two weeks after surgery.
- When should I have a follow-up appointment?
Plan to see your doctor one to two weeks after surgery for an exam and suture removal.
- When can I return to school or work after PCL repair surgery?
Most patients can return to school or desk work three to five days after surgery. Working from home, if possible, makes recovery easier in the beginning. With a physically demanding job, you'll need more time for a safe recovery and medical clearance before returning to work.
- When can I drive after PCL surgery?
That depends on which leg had surgery. If it was your left knee and you have an automatic car, you can drive once you're no longer taking narcotic pain medication and feel capable of driving safely. If you had surgery on your right knee, you'll need to wait three to six weeks after surgery before getting behind the wheel.
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.