The tendon behind the knee is called the patellar tendon, which connects the kneecap (patella) to the tibia (shinbone) . The patellar tendon is one of the strong, fibrous cords that connect muscles to bones in the knee. The quadriceps tendon is another tendon in the knee that joins the thigh to the kneecap (patella) . However, the quadriceps tendon is not located behind the knee.

The four main ligaments in the knee connect the femur (thighbone) to the tibia (shin bone), and include the following:

• Anterior cruciate ligament (ACL): located in the center of the knee, controls rotation and forward movement of the tibia (shin bone).
• Posterior cruciate ligament (PCL): located in the back of the knee, controls backward movement of the tibia (shin bone).
• Medial collateral ligament (MCL): gives stability to the inner knee.
• Lateral collateral ligament (LCL): gives stability to the outer knee.

While tendons connect muscles to bones, ligaments connect bones to each other.