First, the surgical team will give you medicine so you won't feel pain (anesthesia). The medicine may block the pain only in one part of the body (regional), or it may put your whole body to sleep (general). The team will then replace the damaged joint with a prosthesis.
Each surgery is different. How long it takes depends on how badly the joint is damaged and how the surgery is done. To replace a knee or a hip takes about 2 hours or less, unless there are complicating factors. After surgery, you will be moved to a recovery room for 1 to 2 hours until you are fully awake or the numbness goes away.
The femoral component is made of a metal stem with a metal ball on the end. Some prosthesis have a metal head on upper end attached to the metal stem. The acetabular component is a metal shell with a plastic inner liner that acts like a bearing. The type of plastic used is highly cross linked ultra high molecule weight Polyethylene which is wear resistant.