Early detection of loosening is important with hip joint replacements. With early detection, the doctor can save the implant with only minor surgery to replace damaged parts. The patient is better off not having the implant completely removed and replaced.
This case report shows how early changes in the joint implant don’t always show up. This 53-year-old man had a total hip replacement eight years earlier. He had hip pain for the last two years. All lab work, X-rays, and bone scans were normal.
The doctors decided to try using positron-emission tomography (PET) scan. A special form of PET, called F-FDG-PET, was used. This test shows areas of inflammation, a possible sign of implant wear.
In this case, the scan was used to look at the soft tissues around the implant. It showed increased glucose uptake. The inflammatory cells use glucose as a source of energy. The presence of glucose tipped the doctors off that a reaction to implant wear was taking place.
The authors conclude that the specialized PET scan is sensitive enough to show tissue reaction to wear. Identifying wear before loosening occurs may help the doctor decide what kind of operation is needed. Another study with more patients is the next step to confirming this finding.