The Bability And Articulation Of The Hip Joint

The hip joint is the articulation between the pelvis and the femur, characterized by the joint surface opposition of the acetabulum and the head of femur creating a synovial ball and socket joint. It is one of the largest and most stable joints in the body.
Figure ( ): Anatomy of the hip, adapted from (Connecticut, 2006)

The stability of the hip joints is achieved by the depth and congruence of the articular surfaces, further deepened and stabilized by the acetabular labrum. The fibrocartilagenous labrum increases acetabular coverage to just overhalf of the surface area of the femoral head. Stability is further enhanced by the presence of strong joint capsule, the capsular ligaments and surrounding joint musculature.

From a biomechanical perspective, the primary function of the hip joint is to provide adequate motion for the performance of ambulatory tasks and control load transference from the pelvis to the femur.
The ball and socket articulation of the hip allows for a large range of

If the component is sitting superior to the TAL, the cup position (and hip rotation center) has been moved superiorly, which can affect leg length as well as the hip rotation center. If the component is sitting deep to the TAL, the cup position has been medialized, and the offset has thus not been reproduced. An offset liner can then be used to restore the offset, such that the liner sits almost flush with the caudal end of the TAL.
During dynamic activities, the bony congruity of the joint surface and the acetabular labrum limit the magnitude of translation forces, while the ligamentous and muscular structures control rotational forces at the hip joint. Physiological features of the joint cartilage and synovium manage the residual forces and joint reaction forces that