The promising role of 18F-FDG PET in detecting infected lower limb prosthesis implants

The purpose of this study was to evaluate the feasibility of using 18F-FDG and PET for the detection of infection associated with lower limb arthroplasty.

Seventy-four prostheses in 62 patients in whom infection was suspected after artificial hip or knee placement were studied with this technique. Images were obtained 60 min after an intravenous injection of FDG. The images were interpreted as positive for infection if tracer uptake was increased at the bone-prosthesis interface. A final diagnosis was made by surgical exploration or clinical follow-up for 1 y. PET results were compared with the follow-up outcome in all patients.

The sensitivity, specificity, and accuracy of PET for detecting infection associated with knee prostheses were 90.9%, 72.0%, and 77.8%, respectively. The sensitivity, specificity, and accuracy of PET for detecting infection associated with hip prostheses were 90%, 89.3%, and 89.5%, respectively. Overall, the sensitivity was 90.5% and the specificity was 81.1% for detection of lower limb infections.

FDG PET is a useful imaging modality for detecting infections associated with lower limb arthroplasty and is more accurate for detecting infections associated with hip prostheses than for detecting infections associated with knee prostheses.