Doctors make this decision based on many factors. These include the reasons for the joint replacement, the type of joint implant used, and the amount of damage to the joint. For example, a severely arthritic joint may be treated differently from a broken hip.
Each doctor has a schedule of what activities can be done after an operation and when to start each one. This is called a protocol. Putting weight on the new hip joint on the first day after the operation is not unusual. In fact, studies show that early motion helps prevent blood clots and other problems.