Which joint connects the femur to the tibia?

• A. Hip
• B. Ankle
• C. Elbow
• D. Knee

Answer: (D)

Connecting the femur to the tibia is the knee joint. This articulation is the main hinge of the leg, formed where the lower end of the femur meets the upper surface of the tibia, with the patella positioned in front to improve leverage as you bend and straighten the knee. The knee bears the body's weight and enables flexion and extension, with some rotation possible when the knee is bent. The other options connect different bones: the hip links the femur to the pelvis in a ball-and-socket joint, the ankle connects the tibia and fibula to the talus in the foot, and the elbow pairs the humerus with the radius and ulna in the arm. In the knee, the femoral condyles glide on the tibial plateaus, aided by the menisci for cushioning and ligaments for stability.