Abstract
Introduction: Arthroplasty plays a growing role in our society today. Due to scientific and medical progress there are an increasing number of viable candidates and the improvement of quality of life thereafter speaks for itself.
Even though the operations are largely successful, complications after joint replacement surgery occur frequently. Approximately 10% of lower limb arthroplasties need surgical revision, of which 70% are due to loosening. The purpose of this study was to assess the feasibility of 18-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) in detecting septic and aseptic endoprosthetic loosening of hip and knee endoprostheses.
Materials and Methods: Thirty-three patients (age range: 45 – 90y) with lower limb arthroplasty complaints (74 prostheses) were studied preoperatively with 18F-FDG-PET. All patients underwent surgery at a later stage with microbiological culturing to differentiate aseptic and septic loosening and to confirm the final diagnosis. Prostheses were tested intraoperatively for stability and microbiology.
Results: The sensitivity/specificity of 18F-FDG-PET towards implant loosening in the hip was 80%/87%, in the knee 56%/82%.
The sensitivity/specificity for infectious loosening in hip replacement arthroplasties was 67%/83%, in the knee 14%/89%.
Discussion: 18F-FDG-PET seems an excellent method for detecting hip endoprosthetic loosening and a moderate tool to diagnose hip implant infection. It should not be seen as the method of choice to diagnose knee endoprosthetic loosening and infection.
Correspondence should be addressed to Ms Larissa Welti, Scientific Secretary, EFORT Central Office, Technoparkstrasse 1, CH-8005 Zürich, Switzerland
