TC-99M HEXAMETHYLPROPYLENE AMINE OXIME LEUKOCYTE SCINTIGRAPHY FOR THE DIAGNOSIS OF BONE AND JOINT INFECTIONS - A RETROSPECTIVE STUDY IN 116 PATIENTS

The aim of this study was to evaluate the diagnostic value of technetium-99m hexamethylpropylene amine oxime leucocyte scintigraphy (HMPAO-LS) by means of a retrospective review of 116 patients divided into three groups of bone and joint infection. One hundred and thirty-one LS examinations were performed, and 143 sites analysed. The final diagnosis of infection was based on surgical, histological and bacteriological data and follow-up. Ninety-four suspected localizations were examined in group 1, which included 74 patients with an infection suspected to involve orthopaedic implants. In this group, there were 38 true-positives, 1 false-negative, 49 true-negatives and 6 false-positives. Surgical confirmation was obtained in 34 cases. In group 2 (24 patients with suspected osteomyelitis), there were 27 localizations of which 14 were true-positives and 13 were true-negatives (including seven surgical confirmations). In group 3 (18 patients suspected of septic arthritis) there were eight true-positives, two false-negatives, ten true-negatives and two false-positives. Overall sensitivity of Tc-99m-HMPAO-LS for the detection of bone and joint infection was 95%, with a specificity of 90% (group 1: sensitivity 97%, specificity 89%; group 2: 100% and 100%; group 3: 80% and 83%). It may be concluded that HMPAO-LS is an effective tool for the diagnosis of both bone infection involving implants and chronic osteomyelitis.