Injury to which of the following structures would MOST likely account for the increased anterior translation of the tibia in reference to the femur?
The anterior cruciate ligament passes from the medial surface of the lateral femoral condyle to the anterior intercondylar area of the tibia. Its primary function is to prevent anterior translation of the tibia in reference to the femur (or posterior displacement of the femur in reference to the tibia). The Lachman test is the most sensitive examination maneuver for evaluating a anterior cruciate ligament tear. The test is performed with the knee flexed to 30 degrees and the tibia is translated anteriorly with respect to the femur. It is positive if there is increased translation as compared to the opposite side, or more translation than normal. Note: The lateral collateral ligament originates on the lateral femoral epicondyle and inses on the head of the fibula. It functions to prevent varus instability of the knee. When a varus stress (adducted) is placed on the tibia, the lateral collateral ligament becomes taut and prevents displacement. The medial collateral ligament originates from the medial femoral epicondyle and inses on the medial proximal tibia. Its function is to prevent valgus instability of the knee. When a valgus stress is placed on the tibia, the medial collateral ligament is stressed and prevents displacement. The patellar ligament runs from the inferior pole of the patella to the tibial tubercle, and is commonly referred to as the patellar tendon. However, this structure connects bone to bone, which is the definition of a ligament, not a tendon. Ref: Textbook of Ohopaedics & Trauma Vol 1 Page 2940.
Anterior cruciate ligament
Lateral collateral ligament
Medial collateral ligament
Patellar ligament