A prospective study of soft-tissue ultrasonography in sickle cell disease patients with suspected osteomyelitis

Aim: A prospective study was done to assess the accuracy of soft tissue ultrasonography in patients with sickle cell disease (SCD) presenting with suspected osteomyelitis. Materials and Methods: Thirty-one SCD patients had soft tissue ultrasonography on 38 occasions (18 men, 13 women; mean age 8.2 years). The initial ultrasonographic signs and diagnosis were compared with the final clinical diagnosis, which was based on clinical progress and scintigraphy. Result: The overall sensitivity of ultrasound in diagnosing osteomyelitis was 74% with a specificity of 63%. The principal ultrasonographic finding of subperiosteal fluid was present in 14 (74%) patients with osteomyelitis and seven (37%) patients without infection. A finding of a subperiosteal fluid depth of 4 mm or more was significantly associated with osteomyelitis (P < 0.01). Conclusion: Ultrasonography should be the initial investigation in SCD patients if osteomyelitis is suspected clinically. In such a clinical setting, a finding of 4 mm depth or more of subperiosteal fluid appears to be diagnostic. Previous statements that the presence of any subperiosteal fluid indicates infection are shown to be inaccurate. Patients with less than 4 mm of subperiosteal fluid require further imaging or aspiration to establish the diagnosis of osteomyelitis.