What is hip osteoarthritis and stages of it?

A healthy hip has linings of cartilage and lubricating joint fluid (i.e. synovial fluid) to protect and cushion the area between the pelvic and thigh bones, allowing for pain-free hip movements.

However with osteoarthritis, the cartilage lining gradually wears out and the synovial fluid loses its shock-absorbing qualities, producing symptoms of osteoarthritis.