White blood cell scintigraphy for differentiation of infection and aseptic loosening: a retrospective study of 76 painful hip prostheses.
BACKGROUND
Diagnosis of an infected arthroplasty is often difficult. Fever, abnormal physical findings, radiographic changes, findings at bone scintigraphy, an elevated erythrocyte sedimentation rate, CRP, and leucocytosis are not specific enough. We evaluated the diagnostic value of white blood cell scintigraphy.


METHODS
We retrospectively reviewed 76 cases (66 patients) admitted for white blood cell scintigraphy with a clinical suspicion of infection in a hip prosthesis during the period 1995-2003. The leukocytes were labeled with (99m)Tc-HMPAO or with (111)In-oxin. Anterior and posterior views were taken of both hip joints at 3 different time points after injection: 1 h, 3 h, and 22 h. Infection was verified by means of bacteriological cultures, histopathological findings, intraoperative frozen sections, and follow-up (up to 3.5 years).


RESULTS
Of 76 scintigraphies, 51 were negative and 25 were positive. There were 81% true positive, 94% true negative, 6% false positive, and 19% false negative outcomes.


CONCLUSIONS
White blood cell scintigraphy with additional late imaging is an effective tool for differentiation between loosening and infection in painful hip arthroplasty.
Simonsen
Lene
L
Department of Clinical Physiology and Nuclear Medicine, Bispebjerg Hospital, Copenhagen, Denmark. lr01@bbh.regionh.dk
Buhl
Anna
A
Oersnes
Thue
T
Duus
Benn
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D003937:Diagnosis, Differential; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007962:Leukocytes / Q000000981:diagnostic imaging* / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000382:microbiology; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D019690:Technetium Tc 99m Exametazime
D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime