The limited value of radionuclide imaging at symptomatic knee prosthesis

Objective: Determination of the value of bone scanning in symptomatic total knee arthroplasties. Setting: Academic Hospital Maastricht and Maasland Hospital Sittard. Design: Retrospective clinical investigation. Method: The clinical reports of 27 patients, who underwent a bone scintigraphic study, were investigated for complaints and analysis of diagnostic decision making. These patients had persistent symptoms after total knee arthroplasty. In addition, conventional radiographs and the isotope scans were studied without knowledge of the clinical records. Based on these data we evaluated in which cases isotope scanning of the knee had contributed decisively to the further treatment. Results: Isotope scanning did not contribute to the treatment planning if physical examination or conventional radiographs had not led to a clinical diagnosis. This comprised 37% of the patients in our series. If a clinical diagnosis was present, isotope scanning did influence decision making in 65% of the patients. However in the remaining patients with a clinical diagnosis (35%) this was not the case. Conclusion: Radionuclide imaging is of limited value in the diagnostic process of symptomatic total knee arthroplasty. It may support or reject a clinical diagnosis, but in the absence of abnormal findings at physical examinations or radiologic studies, it seldom will induce a change in treatment.