What is a PCL Injury?
The posterior cruciate ligament (PCL) and the anterior cruciate ligament (ACL) are the two ligaments in the middle of the knee. The PCL is oriented from the back of the tibia towards the front of the femur; the ACL is oriented from the front of the tibia towards the back of the femur. The two ligaments cross each other to form an “X”. The PCL prevents the tibia from moving backwards from the femur (posterior translation) and the ACL prevents the tibia from moving forward (anterior translation). Both ligaments help provide rotational stability to the joint.
How Do You Injure the PCL?
A powerful force that pushes the tibia back can injure the PCL. In sports, landing on the shin or getting hit in the front of the upper shin can injure the PCL. Also, the PCL can be torn if the front/inside of the knee is hit and the knee is forced into hyperextension.
What are the Symptoms of a PCL Tear?
Pain and swelling are noted quickly after the injury. The swelling will make the knee stiff and inhibit the quadriceps muscles from contracting normally. The knee usually feels unstable and walking may be difficult.
How is the Diagnosis Made?
The most accurate way to make the diagnosis is through a good history and thorough physical exam by an experienced sports trained physician. The patient can usually provide the details of the injury – how they got hit (if they got hit) and what they felt. The knee will have increased laxity in moving posteriorly. Sitting with the knee bent to 90o, the shin will often sag back compared to the other knee. An ACL tear will have increased forward motion and it takes a trained sports physician to be able to distinguish whether the increased motion in the knee is from going back too far (PCL tear) or from going forwards too far (ACL tear).
Do I Need X-Rays or an MRI?
X-rays are necessary to make sure there is no injury to the bone. An MRI is not essential but can be helpful in assessing other injuries to the knee such as the meniscus or posterolateral corner structures in the knee.
Do I Need Surgery?
If you have injured just the PCL, the injury may heal without surgery. If there are additional injuries to the knee, surgery may be recommended. If the PCL does not heal back tight enough to provide adequate stability for your activities, then the PCL may need reconstructive surgery.
What is the Treatment for PCL Injuries?
A brace may be recommended to help provide stability until muscle strength is restored. Early strength exercises focus on the quadriceps. The quadriceps are important for helping keep the tibia pulled forward (decreasing strain on the PCL). A combination of isolation quadricep exercises (knee extensions), multi-joint exercises (squats and step-ups), and eccentric quadricep work are important to begin as soon as tolerated. Hamstring exercises can place significant strain on the healing PCL and should be avoided initially. After a protection phase, hamstring exercises can be added in; beginning with multi-joint hamstring exercises that do not create knee flexion (for example RDLs and hip extension). Later, isolation hamstring exercises can be started, initially in a limited range (upper range only) and later through a full-range. Your progression will be determined by your physician based on your injury and progression.
When Can I Return to Sports?
The ligament may need 3 to 6 months to heal back strong enough to provide adequate stability in the joint. It may also take 3 to 6 months for muscle strength and neuromuscular function to be restored. A knee brace is often used during the return to sports.
To set up an appointment for further evaluation, please call (208) 336-8250.