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Please ask a qualified health professional about symptoms, treatment decisions, or concerns about your own condition.
Emergency? If symptoms are severe, rapidly worsening, or you think it may be an emergency, call your local emergency number or go to the nearest emergency department.
Bones & Joints
Posterior cruciate ligament (PCL) injuries are tears of the thick ligament running through the center of the knee that prevents the shin bone (tibia) from sliding backward relative to the thigh bone (femur), most commonly occurring from dashboard injuries in motor vehicle accidents, falls onto a flexed knee, or hyperextension injuries in sports. Unlike ACL tears which cause dramatic instability, isolated PCL injuries often cause surprisingly mild symptoms—vague knee discomfort, difficulty with stairs or kneeling, and subtle posterior sag when examined—making them frequently missed or underdiagnosed. PCL tears are graded I-III based on severity (Grade I: partial tear with less than 5mm posterior translation, Grade II: complete tear with 5-10mm translation, Grade III: complete tear with more than 10mm translation often with associated injuries). Isolated PCL injuries (60-70% of cases) are usually managed conservatively with quadriceps-focused physiotherapy achieving 70-80% satisfactory outcomes, as the quadriceps muscle compensates for PCL insufficiency by pulling tibia forward during weight-bearing. However, combined PCL injuries with posterolateral corner (PLC), ACL, or multi-ligament knee injuries require surgical reconstruction to prevent chronic instability and arthritis. PCL reconstruction surgery is technically demanding (done arthroscopically using hamstring or Achilles allograft), with 75-85% achieving good stability but residual mild laxity common, and return to high-level sports taking 9-12 months with many athletes not returning to pre-injury performance level.
What it is and why it happens
Posterior cruciate ligament (PCL) injuries are tears of the thick ligament running through the center of the knee that prevents the shin bone (tibia) from sliding backward relative to the thigh bone (femur), most commonly occurring from dashboard injuries in motor vehicle accidents, falls onto a flexed knee, or hyperextension injuries in sports. Unlike ACL tears which cause dramatic instability, isolated PCL injuries often cause surprisingly mild symptoms—vague knee discomfort, difficulty with stairs or kneeling, and subtle posterior sag when examined—making them frequently missed or underdiagnosed. PCL tears are graded I-III based on severity (Grade I: partial tear with less than 5mm posterior translation, Grade II: complete tear with 5-10mm translation, Grade III: complete tear with more than 10mm translation often with associated injuries). Isolated PCL injuries (60-70% of cases) are usually managed conservatively with quadriceps-focused physiotherapy achieving 70-80% satisfactory outcomes, as the quadriceps muscle compensates for PCL insufficiency by pulling tibia forward during weight-bearing. However, combined PCL injuries with posterolateral corner (PLC), ACL, or multi-ligament knee injuries require surgical reconstruction to prevent chronic instability and arthritis. PCL reconstruction surgery is technically demanding (done arthroscopically using hamstring or Achilles allograft), with 75-85% achieving good stability but residual mild laxity common, and return to high-level sports taking 9-12 months with many athletes not returning to pre-injury performance level.