The hip joint consists of the femoral head (similar to a sphere) and the acetabular cavity of the pelvis (similar to a cup) enclosed by a joint capsule of cartilaginous tissue. The biomechanics of the joint involves also other soft tissues such as ligaments, which help stabilize it by limiting its movements.

The cartilage that covers the articular surfaces protects the bones from direct friction and facilitates the relative sliding during the movements of everyday life.

The onset of some degenerative pathologies (arthrosis, arthritis) can lead to damage to the cartilage and to the reduction of its thickness: the bone surfaces therefore enter in direct contact causing pain.