Objective: In this study, the results of three phase bone scintigraphy and Tc-99m ciprofloxacin scintigraphy were assessed comparatively in the diagnosis of the septic and aseptic loosening of the hip and knee prosthesis.

Materials and Methods: Fifty patients who were referred to our clinic with the pre-diagnosis of infection were included in the study. Thirty two of the patients (64%) had hip prosthesis and 18 (36%) had knee prosthesis. Three phase bone scintigraphy and Tc-99m ciprofloxacin scintigraphy were applied at least 3-5 days interval in our clinic.

Results: Three phase bone scintigraphy was reported as positive for 23 patients (46%) and negative for 27 patients (54%) in terms of infection. Tc-99m ciprofloxacin scintigraphy was reported as positive for 19 (54%) and negative for 31 patients (62%). The sensitivity for the three phase bone scintigraphy was found to be 100%. It was 86.6% for the Tc-99m ciprofloxacin scintigraphy. Specificity was 77.5% versus 82.8% (p<0,05); positive predictive value was 65.2% versus 68.4% (p>0,05); negative predictive value was 100% versus 93.5% (p<0,05); accuracy was 84% versus 84% (p>0,05), respectively.

Conclusion: Besides being a sensitive method, three phase bone scintigraphy can be used confidently in preventing from the infection existence. Since, the specifity of Tc-99m ciprofloxacin scintigraphy is higher when compared with the three phase bone scintigraphy; the usage of both method in the septic-aseptic loosening sorting is suitable.