[en] Full text: Objective: To evaluate the utility of 99mTc-HMPAO labeled leucocyte, 99mTc-labeled anti-granulocyte antibody and 67Ga scintigraphy in patients suspected to have infected hip and knee replacements, from March/1998 to March/ 2002. Methods: Retrospective study of 33 patients (12 male, 21 female) with an average age of 61,1 ± 7,3 years. Nineteen had hip replacements and 14 were submitted to knee replacements. 99mTc-HMPAO labeled leucocyte scintigraphy was performed in 17 patients, 99mTc-labeled anti-granulocyte antibody scintigraphy in 13 patients and 67Ga scintigraphy in 3 patients. Twenty-six patients were also submitted to 3-phase 99mTc-MDP bone scintigraphy. Results were compared to those from studies with infection/inflammation agents. Concordant positive studies were considered to be a positive result for infection. A second study using 67Ga was also performed in 3 patients. Results: Diagnosis was based on surgical findings in 14 patients, pathologic study of biopsy specimen in 1 case and clinical/ imaging follow-up in 18 patients. Infection was detected in 22 cases and absent in 11. The conjoined evaluation of scintigraphic studies considered infection to be present in 20 cases and absent in 13. With infection/inflammation agents, 20 cases were positive (+) and 13 cases were negative (-). Using 99mTc-HMPAO labeled leucocytes, 12 cases were (+) and 5 cases were (-). With 99mTc-labeled anti-granulocyte antibodies, 8 cases were (+) and 5 were (-). With 67Ga, all 3 cases were (-). In patients with (+) studies using infection/ inflammation agents, a false positive case with 99mTc-HMPAO labeled leucocytes was reported. Two false negative cases were detected, both with 99mTc-labeled antigranulocyte antibodies, in patients with (-) studies. Regarding the studies with 99mTc-MDP, 24 were (+) and 2 were (-). Eighteen of these (+) cases were also (+) in studies with infection/inflammation agents, but 6 were (-) with these agents. Negative cases were also (-) in studies with infection/inflammation agents. Conclusions: Scintigraphy with infection/ inflammation agents yielded a sensitivity of 91%, a specificity of 92%, a PPV of 95%, a NPV of 85% and a diagnostic accuracy of 85%. Bone scintigraphy yielded sensitivity, specificity, PPV and NPV values of 100%, 56%, 50% and 100%, respectively. (author)