Leukoscan for orthopaedic imaging in clinical practice.

Studies have suggested that orthopaedic infection can be successfully imaged with 99mTc antigranulocyte antibody Fab' fragments (Leukoscan). This study examined the value of the technique in a UK clinical practice. A retrospective review of the first 55 patients imaged was performed. Patients had three-phase bone scintigraphy followed by Leukoscan imaging. The latter was performed using planar views 2 h and 6 h post-injection of 750 MBq 99mTc Leukoscan. In 47 patients there was adequate clinical information available to compare to the scintigraphy result. There were 13 positive infections. The Leukoscan findings produced 11 true positives, 26 true negatives, eight false positives and two false negatives with resulting sensitivity 85%, specificity 77%, positive predictive accuracy 58%, and negative predictive accuracy 93%. This study suggests that Leukoscan can be used successfully to image orthopaedic infection, with its greatest strength being a high negative predictive accuracy. Positive studies may require further correlative imaging.