Infecton is not specific for bacterial osteo-articular infective pathology

The aim of this study was to re-examine, by retrospective analysis of our case material, the specificity and sensitivity of technetium-99m ciprofloxacin scan in discriminating between infection and other conditions. Tc-99m-ciprofloxacin scintigraphy was performed in 71 patients: 30 patients referred for suspicion of osteomyelitis (OM) or septic arthritis (SA) (group 1) and 41 controls (group 2). Imaging was performed at 4 h post injection and, when possible, at 8 or 24 h post injection. Tracer uptake was visually assessed in different joint groups, and in the sites suspicious for infection. Several soft tissue sites were also evaluated. In the group referred for osteo-articular infection, we found a lower specificity (54.5%) than has previously been reported in the literature. Evaluation of tracer uptake at late imaging did not improve discrimination between sterile and non-sterile inflammation. Additionally, articular uptake was seen in many control patients. Infecton uptake in growth cartilage, thyroid gland, vascular pool, lungs, liver and intestines is discussed.