Ligaments are tough bands of fibrous tissue that connects bone with bone and provide stability to the Joints. There are four Ligaments involved in the Knee Joint. Two Ligaments are present inside the Knee Joint (Cruciate Ligaments) and two Ligaments are present on the outside (Collateral Ligaments). One Ligament that connects the Patella (Kneecap) to Femur (Thigh Bone) is called Medial Patellofemoral Ligament (MPFL).
Cruciate Ligaments (also Cruciform Ligaments) are pairs of Ligaments arranged like the letter X.
The Collateral Ligaments are extra-articular (outside the Knee Joint). The Medial Collateral Ligament is present on the inner side and Lateral Collateral Ligament is a part of the Posterolateral Ligamentous Complex (PLC) which is present on the outer side of the Knee.
Structures found in the Posterolateral Knee include Tibia, Fibula, Lateral Femur, Iliotibial Band (IT band), and the long and short heads of the Biceps Femoris Tendon, Fibular Collateral Ligament (FCL), Popliteus Tendon, Popliteofibular Ligament, Lateral Gastrocnemius Tendon and Fabellofibular.