Hip replacement surgery. Image 29 of 30. Surgeon's hands sewing up after hip replacement surgery. The final skin layer is being sewn back together. The old hip joint was surgically excised and replaced with a new one. This surgery is usually performed in response to arthritis, degeneration of the joints, and restores mobility to people who would otherwise be incapacitated by pain and unable to move freely. For a sequence of images showing the full surgery, see M551/340-369.