Usefulness of 99mTc-ciprofloxacin scintigraphy in the diagnosis of prosthetic joint infections.
OBJECTIVE
To evaluate the usefulness of 99Tc-ciprofloxacin scintigraphy (CFS) in patients with hip or knee arthroplasty and suspected infection.


METHODS
Forty patients (26 women, 14 men) with a mean age of 66±10 years and local pain in the hip (21), knee (16), or shoulder (three) prosthesis were recruited. CFS was performed at 1, 4, and 24 h after intravenous injection of 370 MBq. Anterior and posterior views centered on the affected joint were performed in all patients. A routine bone scan, 99Tc-hexamethylpropyleneamine oxime leukocyte scan, and 99Tc-colloid scan [leukocyte scintigraphy-bone marrow scintigraphy (LS-MS)] were performed. Final diagnosis of infection was confirmed by positive microbiological analysis or macroscopic evidence of purulent material.


RESULTS
Diagnosis of arthroplasty infection was established in 16 out 40 cases: coagulase-negative staphylococci (nine), Staphylococcus aureus (three), Enterococcus (one), and macroscopic infection in the remaining three cases. CFS imaging showed the 24-h image to be the best acquisition time-point. The sensitivity, specificity, negative predictive value, and positive predictive value for LS-MS were 75, 92, 86, and 85%, whereas for CFS at 24 h these figures were 88, 71, 67, and 89%. The sensitivity and specificity for LS-MS and for CFS at 24 h for hip were (74, 90, and 88, 85%) and for knee (83, 90 and 100, 50%).


CONCLUSIONS
CFS can be useful in the diagnosis of arthroplasty infection of the hip as a substitute for LS-MS. It is recommended that CFS images be obtained 24 h after injection. The lack of specificity of CFS makes this technique inadequate for knee prostheses in this series.
Department of Nuclear Medicine, Hospital Clínic, UAB, Barcelona, Spain. dfuster@clinic.ub.es
David
D
Fuster
Alex
A
Soriano
Sebastian
S
Garcia
Carlos
C
Piera
Joan
J
Suades
Dani
D
Rodríguez
Juan C
JC
Martinez
Josep
J
Mensa
Francisco
F
Campos
Francesca
F
Pons
D000368:Aged; D001178:Arthroplasty / Q000009:adverse effects; D002939:Ciprofloxacin / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000000981:diagnostic imaging*; D008297:Male; D015609:Organotechnetium Compounds; D016459:Prosthesis-Related Infections / Q000000981:diagnostic imaging*; D011877:Radionuclide Imaging / Q000379:methods*; D012680:Sensitivity and Specificity
D015609:Organotechnetium Compounds; C431804:Technetium Tc 99m ciprofloxacin; D002939:Ciprofloxacin