Sometimes, a hip replacement may not work correctly. There is a wide range of reasons that a hip replacement may not work. Some of the most common reasons include: infection, dislocation, loosening of the parts, fracture of the bone, and allergic reactions. A second surgery, also known as a revision surgery, may be required to fix the problem. A revision hip replacement is also known as a revision hip arthroplasty. The revision surgery may require replacing one or several of the parts from the prior hip replacement. In the case of very complicated problems like infections, more than one revision surgery may be necessary to adequately fix the problem. Revision surgery generally requires a short hospital stay.