Posterior Cruciate Ligament (PCL) Tear

The posterior cruciate ligament (PCL) is the strongest intra-articular knee ligament, originating from the medial femoral condyle and inserting on the posterior tibial sulcus, primarily restraining posterior translation of the tibia relative to the femur and rotational stability. PCL tears are less common than ACL tears, accounting for 3-20% of all knee ligament injuries; combined PCL injuries (with ACL, PLC, MCL) are common in high-energy trauma and knee dislocations.

Mechanisms include direct posterior force to the proximal tibia (dashboard injury in motor vehicle collisions), forced hyperflexion with plantar-flexed foot (sports), and hyperextension. Symptoms include posterior knee pain, swelling, instability with descending stairs or pivoting, and difficulty with deceleration; chronic untreated grade III injuries lead to medial and patellofemoral chondral wear and osteoarthritis.

Diagnosis combines history, posterior drawer test (most sensitive, graded by tibial translation), Godfrey sag sign, quadriceps active test, and contralateral comparison; MRI confirms substance tears, peel-off avulsions, and combined injuries; stress radiographs quantify translation. Grade I (1-5 mm), II (6-10 mm), and III (>10 mm) inform management. Conservative care for grade I-II with quadriceps strengthening and dynamic PCL brace; grade III, combined injuries, bony avulsions, and chronic symptomatic instability are managed with arthroscopic single-bundle (transtibial or tibial inlay) or double-bundle reconstruction with PLC and other ligament repair as needed.