Ultrasound of Musculoskeletal Infections.

Ultrasound (US) can play an important role in differentiating infectious processes from other musculoskeletal diseases. US is the imaging modality of choice to diagnose superficial abscesses. These abscesses may have variable echogenicity and their detection can be facilitated by ultrasonographic dynamic evaluation and color Doppler imaging. Septic arthritis either in a native or prosthetic joint may have devastating complications on the joint function. Early diagnosis requires joint fluid analysis. US is very sensitive in the detection of joint effusions and is helpful to guide the arthrocentesis. US may help in the early diagnosis of osteomyelitis, although one must always remember that a normal US never excludes bone infection. This article also reviews the role of US in the diagnosis of necrotizing fasciitis, tenosynovitis, bursitis, and pyomyositis. After initial radiographs, along with nuclear medicine studies, US should be considered as the next imaging step in the investigation of musculoskeletal infections.