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Knee recovery depends on severity of sprain

Sat., Oct. 19, 2013

DEAR DOCTOR K: I injured my PCL playing football. How long will my recovery take?

DEAR READER: Let’s start with some knee anatomy. The posterior cruciate ligament (PCL) and the anterior cruciate ligament (ACL) are two tough bands of fibrous tissue. The ACL is injured more often than the PCL, which is why many people have heard of the ACL but not the PCL.

The ACL and PCL connect the thighbone (femur) and the large bone of the lower leg (tibia) at the knee joint. The ACL and PCL form an “X” pattern that stabilizes the knee against front-to-back and back-to-front forces.

A PCL injury is a sprain – a stretch or tear of the ligament. PCL sprains are classified as follows.

People get PCL injuries when their knee is flexed (like when you are seated) and the large bone of the lower leg is hit hard. For example, a person might be seated in the front seat of a car. If the car is in an accident and the person’s lower leg smashes into the dashboard, that could cause the injury.

Usually, people with a sudden new PCL injury notice less of a problem with the knee than people with a new ACL injury, at least at first.

Your doctor may also recommend a nonsteroidal anti-inflammatory drug, such as ibuprofen, to relieve mild pain or swelling.

Full recovery can take from four months to a year. How long your specific injury lasts will depend on the severity of your PCL injury and your rehabilitation program. Probably the most important thing you can do are exercises to strengthen your quadriceps muscles – the muscles in the front of your thigh. The chances are good you will return to your pre-injury level of function.

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.


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