3 terms

PCL/ACL - Knee

Posterior Cruciate Ligament (PCL)
Attachments: Posterior Tibia to Medial Femoral Condyle

Alignment: Parallel to lateral collateral ligament and perpendicular to ACL

Function: Key stabilizer of knee joint. Check anterior movement of femur on the tibial plateau (prevents femur from sliding forward)

Injury: Abnormal passive posterior displacement, posterior drawer sign
Anterior Cruciate Ligament (ACL)
Attachments: from anterior tibia to lateral femoral condyle anteriorly

Alignment: perpendicular to lateral collateral ligament and PCL (slightly shorter than PCL)

Function: Key stabilizer of knee joint. Check posterior movement of femur on tibial plateau, prevents anterior displacement of tibia with respect to Femur

Injury: Anterior Drawer Sign, tibia slides in front of the whole knee, buckling of the knee occurs
Unhappy Triad
3 Ligaments Injured: MCL, ACL, Medial Meniscus; Very rare for one to be torn without the others because they are attached.

Happens during sports (football/skiing); Clipping- tackling around knee area with shoulder

Fixable injury via arthroscopic surgery - instrumentation can visualize without opening the knee; will loose some strength/flexibility