There are many possible reasons for thigh pain. A problem with the implant (also called a prosthesis) is only one. Loosening of the prosthesis is the most common cause of thigh pain linked with a total hip replacement.
Other medical causes such as urinary tract infection, kidney stones, or disc herniation must be ruled out. Your surgeon is the best one to diagnose the problem. After taking a history and performing an exam, a simple X-ray may be all that’s needed.
If the problem is not coming from the implant, then other imaging and/or lab tests may be needed. Early diagnosis and treatment are always advised. Waiting too long can sometimes add complications that may be avoided with early intervention.