The posterior cruciate ligament (PCL) is in the posterior central knee and keeps the tibia from shifting backwards, relative to the femur. The PCL can be partially or completely torn.
PCL tears often occur alongside other knee injuries. High-energy mechanisms such as dashboard injuries or knee dislocations commonly involve combined damage to the PCL and the MCL or LCL. Even lower-energy PCL injuries should be evaluated for concurrent ACL involvement and meniscus tears, which frequently co-occur.
Causes
Sports related causes.
PCL injuries occur when the tibia is shifted posteriorly relative to the femur — as in a car accident (dashboard type injury), hyperflexion of the knee, falling onto a flexed knee, or an awkward landing after a jump.
Symptoms
Patients with PCL injuries may experience knee pain, swelling, difficulty walking, and instability.
Diagnosis
A physical exam by a doctor is performed to determine if the tibia maintains a normal relationship with the femur when pushed posteriorly.
If the physical exam is inconclusive, a knee MRI is the most accurate way to evaluate the integrity of the PCL, grade the severity of the tear, and identify any associated injuries to the meniscus, joint capsule, or other ligaments that may alter the treatment plan.
PCL Injury Grades
Doctors use a grade to indicate how severe a PCL injury is and to choose the appropriate treatment.
- Grade 1: Partial tear (sprain) from stretching of the ligament fibers and minimal laxity (1–5 mm of posterior translation of the tibia relative to the femur).
- Grade 2: Complete tear of the PCL but no other significant injuries (6–10 mm of posterior tibial translation).
- Grade 3: Complete tear of the PCL and injury of the joint capsule and/or other knee ligaments. The tibia is shifted posterior to the femoral condyles (>10 mm of posterior tibial translation).
Conservative Treatment
PCL tears typically heal and treatment is supportive with rest, icing, elevation, ace bandaging, and anti-inflammatory medicines.
Grade 1 or 2 injuries: Braces and physical therapy will help support the knee while strengthening the muscles and allowing the PCL to heal, which may take 2 to 4 weeks.
Grade 3 injuries: Immobilization of the knee for one month followed by passive range of motion therapy and eventual muscle strengthening.
Operative Treatment
Surgery for the PCL is rare and is reserved for the most severe injuries that may be associated with knee dislocation, bone avulsion fractures, tears of the joint capsule and ligaments, and complex meniscus tears. Surgery may also benefit patients with chronic PCL tears that have failed conservative therapy and continue to cause knee pain and instability.
Related Knee Conditions
- ACL Tear
- MCL and LCL Sprain
- Meniscus Tear
- Patellar Dislocation
- Osteochondral Defect
- Back to all Knee Conditions
Get an MRI to Confirm Your Diagnosis
Before surgical planning or starting treatment, a clear MRI diagnosis ensures the right path forward. First Look MRI offers self-pay Knee MRI scans — no doctor's order or insurance required — at our locations in Georgia, Texas, and Colorado.