False negative 99m Tc-hydroxymethane diphosphonate three-phase bone scintigraphy and 99m Tc-besilesomab scan in detecting tibia osteomyelitis concomitant with necrotizing fasciitis

Abstract

We described a case of 51-year-old female patient presented with a right calf necrotising fasciitis (NF) where osteomyelitis (OM) was suspected. 99m Tc-hydroxymethane diphosphonate three-phase bone scintigraphy and 99m Tc-besilosomab scan failed to demonstrate classical features of OM. The final diagnosis was only made by isolating Acinetobacter sp. in both intra-operative bone and tissue cultures from below-knee amputation. As conclusions, the detection of lower limb OM by 99m Tc-besilosomab scan is not easy when there is concurrence overlying NF. The unusual three-phase bone scan finding of pericortical accumulation of tracer as an early sign of OM is highlighted in this case.