Posterior Cruciate Ligament Injury
The posterior cruciate ligament (PCL) is a thick band of tissue deep inside the knee that connects the thighbone to the shinbone. The PCL prevents the shinbone from sliding too far backward under the thighbone. Any force that pushes the shinbone backward under the thighbone can cause a PCL injury. The PCL may be stretched, partially torn, or completely torn.
Knee injuries that tear the PCL often damage other ligaments or cartilage in the knee. A PCL injury can also break a piece of bone loose within the knee. PCL injuries can occur quickly—with a blunt force injury to the knee—or slowly, as the ligament is stressed over time.
How Does it Feel?
With an injured PCL, you may experience:
Sharp or dull pain deep inside the knee joint or the back of the knee
Pain in the knee when lifting a heavy load
Pain when walking longer distances
Swelling throughout the knee
Stiffness in the knee
A wobbly feeling in the knee
Difficulty walking on the injured leg
Difficulty going up or down stairs
Difficulty when starting to run
PCL injuries sometimes do not cause a “popping” sound or sensation when they first occur, and for that reason, people may not be sure of the exact time of their injury.
How Is It Diagnosed?
If you see your physical therapist first, the therapist will conduct a thorough evaluation that includes taking your health history. Your physical therapist will also ask you detailed questions about your injury, such as:
How and when did you notice the pain?
Did you feel pain or hear a “pop” when you injured your knee?
Did your knee straighten out very quickly, past its normal position?
Did your knee get forcefully bent, past its normal position?
Did you receive a direct hit to the leg while the knee was bent?
Did you fall on a bent knee with the foot pointed downward?
Did you see swelling around the knee in the first 2 to 3 hours following the injury?
Does your knee feel like it is wobbling, locking, catching, buckling, or giving away when you try to use it?
Your physical therapist also will perform special tests to help determine the likelihood that you have a PCL injury. Your physical therapist will gently press on the front of your knee to determine if the ligament feels loose, and may perform additional tests to determine if other parts of your knee are injured. Your physical therapist will also observe how you are walking.
To provide a definitive diagnosis, your physical therapist may collaborate with an orthopedic physician or other health care provider, who may order further tests, such as an x-ray, to confirm the diagnosis and to rule out other damage to the knee, including fracture.
How Can a Physical Therapist Help?
Your physical therapist will work with you to design a specific treatment program that will speed your recovery, including exercises you can do at home. Physical therapy will help you return to your normal lifestyle and activities. The time it takes to heal the condition varies, but improvement is generally noted in 2 to 12 weeks.
During the first 24 to 48 hours following your injury, your physical therapist may advise you to:
Rest your knee by using crutches or a brace, reducing the amount of weight you put on your injured leg, and avoiding any activity that causes pain.
Apply ice packs to the area for 15– to 20 minutes every 2 hours.
Consult with a physician for further services such as medication or diagnostic tests.
Your physical therapist will work with you over time to:
Reduce Pain and Swelling
Your physical therapist may use a variety of treatments and technologies to control and reduce your pain and swelling, which may include ice, heat, ultrasound, electrical stimulation, taping, exercises, and hands-on therapy, such as massage.
Your physical therapist will choose specific activities and treatments to help restore normal movement in the knee and leg. These might begin with passive motions that your physical therapist performs for you to gently move your leg and knee joint, and progress to active exercises and stretches that you do yourself.
Your physical therapist will determine if any of your leg muscles are tight, and teach you how to stretch them with gentle exercise.
Certain exercises will aid healing at each stage of recovery; your physical therapist will choose and teach you the correct exercises and equipment to steadily restore your strength and agility. These may include the use of cuff weights, stretch bands, weight-lifting equipment, and cardio-exercise equipment, such as treadmills or stationary bicycles.
Regaining your sense of balance is important after an injury. Your physical therapist will teach you exercises to improve your balance skills.
Speed and accuracy of leg movement is important in athletic activities. Your physical therapist will help you regain these skills in preparation for a return to sports activities.
Speed Recovery Time
Your physical therapist is trained and experienced in choosing the best treatments and exercises to help you heal, return to your normal lifestyle, and reach your goals faster than you are likely to do on your own.
Your physical therapist will work with you to set your work, sport, and home-life recovery goals. Your treatment program will help you reach those goals in the safest, fastest, and most effective way possible. Your physical therapist will teach you exercises, work retraining activities, and sport-specific techniques and drills to help you return to your regular activities.
If Surgery Is Necessary
Surgery is not usually required to treat a mild PCL injury. However, it may be needed if:
The PCL is completely torn
A piece of bone has broken loose
There are other ligament injuries
You constantly feel like your knee is going to buckle beneath you
Athletes may elect to undergo surgical replacement of the PCL to improve the stability of the knee during sports activities. If other parts of the knee are injured at the same time as the PCL, you may need different treatment for those injuries, including surgery. If surgery is needed, you will follow a recovery program over several weeks guided by your physical therapist. Your physical therapist will help you minimize pain, regain motion and strength, and return to normal activities in the speediest manner possible.
Can this Injury or Condition be Prevented?
Your physical therapist can recommend a home-exercise program to strengthen and stretch the muscles around your knee, upper leg, and abdomen to help prevent future injury. These may include strength and flexibility exercises for the leg, knee, and core muscles.
To help prevent a recurrence of the injury, your physical therapist may advise you to:
Always use a seat belt to help prevent injury during a car accident.
Position your car seat so it is not too close to the dashboard.
Avoid intentionally landing on the front of your shinbone or on your knees.
Always warm up before starting a sport or heavy physical activity.
Maintain or improve sport-specific conditioning and techniques that are right for your level of sport activity.
Wear shoes that are in good condition and fit well.
Maintain a healthy weight.
Real Life Experiences
Steven is a 35-year-old nurse. While driving home one day, he is involved in an accident. His knees hit his car’s dashboard very hard. His left knee is bruised but otherwise fine; the right knee feels painful and swells overnight. After a few days, the right knee does not feel better and starts to feel wobbly. He is not able work. He calls his physical therapist.
Steven’s physical therapist is able to see him immediately, and thoroughly examines the knee. She can see there is swelling throughout the knee-joint area. The bruised areas are painful when she gently touches them. She tests the ligaments of the knee and finds that the PCL is noticeably looser than the PCL on the other leg. She determines that the PCL is moderately sprained—overstretched, but not torn. She applies an ice pack and electrical stimulation to help reduce the pain and swelling, and a brace to support the knee and limit bending. She teaches Steven how to use crutches, and advises him to consult with his personal physician to rule out a bone fracture. His physician confirms the diagnosis of PCL sprain.
When Steven returns for his next session, his physical therapist teaches him gentle motion and strengthening exercises. Over the next few weeks, she helps him progress through a rehabilitation program that includes strengthening, stretching, and balance exercises. The physical therapy program reduces the swelling and restores the knee’s motion and strength, so that Steven no longer needs crutches after 2 weeks, and he is able to stop using the brace after 3 weeks. After about 6 weeks, Steven is able to resume all of his normal daily activities, including his full-time duties as a nurse.