Point-of-care ultrasound (POCUS) for the evaluation of fractures and dislocations in the Emergency Department (ED) has been established in the literature and is not difficult to perform with minimal ultrasound (US) experience or brief focused training. Benefits include reduced cost, increased patient satisfaction, increased ED throughput, and decreased time to pain control.1,2
Acute fractures and dislocations are frequently seen in the ED. Radiographs can be normal and the next step is computed tomography (CT) or magnetic resonance imaging (MRI). These modalities are expensive, time consuming, and may not be available. US is an option for the initial diagnosis. US has advantages over radiographs including multiplanar imaging, ability to be performed at the bedside, and no ionizing radiation.
US as an initial imaging modality may obviate the need for a radiograph in a patient with a low suspicion for fracture or dislocation. It can be done at the bedside at the time of the physical examination. The patient does not have to wait for a radiograph, would not incur the cost of a radiograph, is more likely to be happy with their care than if they had received no imaging at all, and receives no ionizing radiation.2 Patients with a fracture often go on to require a radiograph to better characterize a fracture. There are circumstances (e.g., sternal fractures) where US can be more sensitive and a radiograph is unlikely to change patient management.3,4 Rapid evaluation with US allows the Emergency Physician to make a better and more specific choice to control pain. An intraarticular injection or a peripheral nerve block may be a better choice than intravenous (IV) opioids.
This chapter covers the basics of US for long bone fractures and two of the most common dislocations in adults (e.g., the shoulder and elbow). Its use in other joint dislocations is similar.
ANATOMY AND PATHOPHYSIOLOGY
Bone is hyperechoic or bright white on the US screen and casts a dense shadow (Figure 100-1). The hypergenicity is from the differences in acoustic impedance between bone and surrounding soft tissues. The cortex is bright white and continuous, has posterior shadowing, and often shows a reverberation artifact. It is the brightest soft tissue structure seen on musculoskeletal US. This includes fascia, fat, muscle, subcutaneous tissue, tendons, and vessels. It can be brighter when the US transducer is directed transverse to the bone. The deep structures of the bone are not visible due to the high acoustic impedance of the cortex.
The rest of the musculoskeletal structures are visible adjacent and superficial to the bone. Fascial planes can be similarly bright as bone on US but do not produce a shadow. Air is visualized as bright and ...