Bones of the Knee Joint

The Knee joint is made up of 4 bones; namely Femur, Tibia, Fibula and Patella. Femur, the longest bone of the body, articulates in the knee joint at its distal end and it is the proximal end of Tibia and Fibula that articulates with the Femur in Knee. Patella is the Knee cap. It should be noted that though the distal end of Femur and proximal end of Tibia articulate, they are not exactly complimentary to each other. The Femur ends distally into two protruding globes known as Condyles. Condyles are cancellous in nature and covered with Hyaline cartilage at their tips to minimise the friction when they glide on the Tibial surface. The femoral condyles form a deep groove called Intercondylar Notch between themselves. This notch is a very important landmark in the joint because through it pass the ACL and PCL. As mentioned, Tibia has a plateau-like surface at its proximal end that articulates in the knee joint. This Tibial plateau accommodates the Condyles of Femur. To accommodate Femoral Condyles, Tibial plateau has two concave Condyles. These condyles cover most part of the Tibial plateau. Of the two, medial Tibial Condyle is more concave, longer in anterior-posterior direction and more oval while lateral Tibial Condyle is flatter and more rounded. This is to accommodate the bigger medial Femoral Condyle and rounder lateral Femoral Condyle. The other bone of the calf, i.e. Fibula is comparatively much weaker and runs lateral to Tibia.

Patella is a seed-shaped bone suspended in the Femoral Quadriceps Tendon. On its posterior surface, Patella has 7 grooves that come in contact with Femur during flexion and/or extension.