Musculoskeletal infections: US manifestations

One of the most important prognostic factors in patients with musculoskelet al infections is the delay in establishing therapy. Early diagnosis of sept ic arthritis requires analysis of joint fluid. Ultrasonography (US) is a ra pid, portable, sensitive technique for confirming the presence of joint eff usions, The study can be easily repeated for follow-up of lesions. US allow s real-time guidance of fluid aspiration and can reduce the risk of contami nating other anatomic compartments, especially in the hands, wrists, and fe et. Radiography provides complementary information and should be performed in conjunction with US. US is the imaging modality of choice for diagnosis of superficial abscesses. Dynamic compression with the US probe and color D oppler imaging can facilitate detection of superficial abscesses. US may he lp in the early diagnosis of osteomyelitis by demonstrating subperiosteal o r juxtacortical fluid collections and by providing guidance for aspiration of these collections. Evaluation of osseous involvement requires additional imaging; a US examination with normal results does not allow exclusion of bone infection. US is not degraded by metallic artifact and may be useful i n cases of osteomyelitis complicating metallic fixation in an extremity. Af ter initial radiography, US can play an important role in the management of musculoskeletal infections.