Indium-111 leukocyte scintigraphic detection of subclinical osteomyelitis complicating delayed and nonunion long bone fractures: a prospective study.

Twenty patients were studied prospectively with indium-labeled leukocyte imaging to evaluate its effectiveness in differentiating noninfected delayed or nonunion from osteomyelitis complicating these entities. All patients underwent an open surgical procedure within 24 h of the scan. Bone specimens from the nonunion site were obtained for microbiological and histological analysis to confirm the presence or absence of osteomyelitis. In these twenty patients, the sensitivity of the indium scintigraphy was 100%, the specificity 100%, and the overall accuracy 100%. Indium-labeled leukocyte scintigraphy is significantly more accurate than 99mtechnetium and 67gallium imaging had been, when studied earlier, in detecting subclinical osteomyelitis complicating nonunion. Indium-labeled leukocyte scintigraphy should supplant sequential technetium and gallium studies in this patient population when the surgeon must determine whether subclinical osteomyelitis is complicating fracture management of delayed and nonunions.