Diagnosis of peri-prosthetic loosening of total hip and knee arthroplasty using 18 F-Fluoride PET/CT

// Sebastian Koob 1 , Florian C. Gaertner 2 , Tom Rainer Jansen 1 , Jan Schmolders 1 , Sascha Gravius 1 , Holger Strunk 3 , Dieter Christian Wirtz 1 and Markus Essler 2 1 Clinic for Orthopedics and Trauma Surgery, University of Bonn, Bonn, Germany 2 Clinic for Nuclear Medicine, University of Bonn, Bonn, Germany 3 Department of Radiology, University of Bonn, Bonn, Germany Correspondence to: Sebastian Koob, email: sebastian.koob@ukbonn.de Keywords: periprosthetic loosening; bone imaging; total hip arthroplasty; periprosthetic infection; 18 F-Flouride PET/CT Received: October 11, 2018     Accepted: February 01, 2019     Published: March 15, 2019 ABSTRACT Periprosthetic loosening, either aseptic or induced by periprosthetic joint infection remains a major long term complication and challenge in orthopedics and trauma surgery. Sensitivity of potential loosening of the material and other causes of a painful prosthesis is essential for choosing the respective treatment option and providing the needed resources. 18 F-Fluoride is a radiopharmaceutical which shows a high affinity to bone and a rapid blood clearance. The objective of this study was to assess 18 F-Fluoride PET/CT´s sensitivity and specificity in diagnosing periprosthetic loosening in total hip and knee arthroplasty. We included 26 patients with 24 hip and 13 knee prostheses in our retrospective study with radiological or clinical suspicion of peri-prosthetic loosening at least one year after implantation. Results of 18 F-Fluoride PET/CT imaging were compared with surgical results or clinical follow-up if surgery was not performed. On the basis of our data we found a sensitivity of 95.00 %, a specificity of 87.04 % and an accuracy of 89.19 % for 18 F-Fluoride PET/CT. The results of our study show that 18 F-Fluoride PET/CT is a useful and promising technique in diagnosing periprosthetic loosening of total hip and knee arthroplasties. Further investigation should focus on different uptake patterns of the isotope in periprosthetic joint infection and therefore distinguishing aseptic from septic loosening and enhancing the diagnostic value of this imaging method.