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 Hip Anatomy

X-ray of hip joints

The hip is one of the largest joints in your body. It is made up by the pelvic bone and the thigh bone.

The hip joint is often called the ‘ball and socket’ joint. The ball is at the head of the thigh bone (femur). The socket is the cup-shaped bone of the pelvis (acetabulum).

In a normal hip joint, the round ball of the upper thigh bone (femur) fits into the cup-like socket (acetabulum) of the pelvic bone. The hip joint’s ball and socket allows you to move around freely, and gives you the stability and support you need to stand up and carry your body weight.

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How does the hip joint work?

The hip is a large joint that holds a lot of weight. The hip joint allows your leg to move forward, backward, from side to side, and to turn. Your hip joint lets you walk, climb stairs and do other daily activities.

Three things that help the hip joint work easily and without pain:

  1. The smooth coating over the bones, called cartilage.
  2. The slippery fluid inside the joint, called synovial fluid.
  3. The muscles and ligaments that support and move the hip.

Three things that make the hip painful and hard to move:

  1. The smooth coating over the bones (cartilage) becomes rough and wears away.
  2. The muscles weaken.
  3. The slippery synovial fluid in the hip starts to dry up.

Arthritis and other diseases can damage the cartilage in your hip joint. If you are feeling a lot of pain and discomfort every day, you should see your doctor.

Why do I need a hip replacement?

Most people have a hip replacement because the cartilage between the bones in their hip has worn away. The bones are now rubbing against each other, causing pain and stiffness in the hip.

The pain may be keeping you awake at night, and affecting your everyday life. You may have had to cut back, or stop, many of your daily activities such as working, going for a walk, going up and down stairs, gardening and shopping.

You may need hip replacement surgery if the hip joint gets to a point when you can’t control the pain any more with other treatments. It is the second most common joint replacement procedure. Hip replacement surgery has a high success rate, and can improve your quality of life. Your pain should stop, or at the very least, you should feel less pain and discomfort. Your new hip should be more flexible, allowing you to go about the activities of your everyday life.