Imaging of infected total arthroplasty with Tc-99m-labeled antigranulocyte antibody Fab'fragments.
OBJECTIVE
The objective of this study was to evaluate the diagnostic accuracy of Tc-99m-labeled antigranulocyte antibody Fab' fragments in infected total arthroplasty.


METHODS
A total of 38 immunoscintigrams were evaluated retrospectively with 15 to 25 mCi Tc-99m-labeled antigranulocyte antibody-Fab' fragments. The final diagnosis was assessed by articular puncture or intraoperative sampling.


RESULTS
In the total hip replacement group the authors found 10 true positives, 7 true negatives, 8 false positives, and 1 false negative; and in the total knee replacement group they found 4 true positives, 8 true negatives, and no false positives or false negatives. They also found a sensitivity of 93%, a specificity of 65%, and a positive predictive accuracy of 63%. There was a negative predictive accuracy of 94%.


CONCLUSIONS
The high negative predictive accuracy in the whole group suggests that the scan can be used to exclude infection in most cases. Negative results with a high clinical suspicion merits further investigation. A positive result will require further correlative imaging, especially for total knee replacement.
St. Josef Hospital, University Hospital, Department of Radiology and Nuclear Medicine, Bochum, Germany. thomas.rothenburg@t-online.de
Thomas
T
von Rothenburg
Martin
M
Schoellhammer
Josef
J
Schaffstein
Odo
O
Koester
Gebhard
G
Schmid
D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D005260:Female; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D007720:Knee Prosthesis / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D016459:Prosthesis-Related Infections / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000473:pathology; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D019275:Radiopharmaceuticals; C101172:Sulesomab