Primary septic arthritis in heroin users: early diagnosis by radioisotopic imaging and geographic variations in the causative agents.

We reviewed 37 cases of septic arthritis in heroin users. Our data confirm the predominance of the fibrocartilaginous joint infections in this group (sacroiliac joint 39%, chondrosternocostal unions 37%). In Spain, Staphylococcus aureus is the most commonly isolated organism (73%). This emphasizes the geographic variations in the causative germs since, in contrast to other reports, we have not identified any gram negative bacillary arthritis in our population of heroin users. Our data show that the 67gallium citrate scintigraphy is positive earlier than the 99mTc-MDP bone scan in the poorly vascularized joints (p less than 0.0005). The early localization of the infectious focus by 67gallium citrate scintigraphy followed by a prompt bacteriologic diagnosis (blood, synovial fluid or tissue cultures) allowed good therapeutic results.