The hip joint comprises two bones – the femur (the thigh bone), and the pelvis which in fact comprises three separate bones – the ilium, the ischium and the pubis, which are completely fused together by the age of 20. The joint itself is where the 'femoral head' (the ball joint at the top of the thigh bone) sits in the 'acetabulum' – the socket on the outer edge of the pelvis. The entire joint comprises these two bones within a joint 'capsule' along with associated muscles and ligaments, nerves and blood supply, and a layer of cartilage cushioning the ball and socket and two small fluid filled sacs called 'bursae' which act as small cushions allowing muscles and ligaments to move smoothly. The hip joint is the largest weight bearing joint in the human body.
The most common issues and conditions affecting the hip joint include:
Arthritis
Arthritis of the hip joint is fairly common and affects the layer of cartilage between the femoral head and the acetabulum.
Infection
The hip joint can be affected by infection either of the bone or of the joint itself.
Read more about infection of the hip
Bone loss
Bone loss – also known as osteoporosis – affects all bones in the body, including the bones of the hip joint.
Complex revision
A 'revision' is the name given to any corrective surgery that needs to be performed on a previous hip replacement. There are a number of reasons why a complex revision may be necessary.