Hip Joint Effusion

Zieger MM, Dorr U, Schulz RD et al (1987) Ultrasonography of hip joint effusions. Skeletal Radiol 16 607-611... 

US demonstrates hip joint effusion by examining the anterior recess of the capsule (Seltzer et al. 1980 Wilson 1984 Marchal et al. 1987 Zawin et al. 1993). The main anatomic landmarks of this recess are the anterior border of the acetabulum, the femoral epiphysis, the articular cartilage, the growth plate and the femoral neck (Fig. 19.8a). The anterior recess is evaluated with the child supine... 

Yeow K-M,Tan C-F, Chen J-S et al (2000) Diagnostic sensitivity of ultrasound-guided needle biopsy in soft tissue masses about superficial bone lesions. J Ultrasound Med 19 849-855 Zawin JK, Hoffer FA, Rand FF et al (1993) Joint effusion in children with an irritable hip US diagnosis and aspiration. Radiology 187 459-463... 

Fig. 12.12a-d. Anterior recess of the hip joint. a,b Transverse oblique 12-5 MHz US images with c,d schematic drawing correlation obtained over the hip joint in a healthy subject (a,c) and in a patient with intra-articular effusion (b,d). In the hypoechoic... 

In normal conditions, the iliopsoas bursa cannot be visualized with US because its cavity contains only a thin film of synovial fluid. When communicating with the joint cavity, hip joint fluid can enter the bursa (Fig. 12.34a). In cases of abundant joint effusions, the bursa acts primarily as a reservoir thus limiting the damage to the intra-articular structures related to a high intra-articular pressure. Intra-... 

A normal hip shows a concentric reduction of the femoral head in the acetabulum - the joint space is equidistant all around the hip. The tear-drop represents the medial wall of the acetabulum. The distance from the tear-drop to the femoral head maybe compared with the contralateral side. On a perfectly positioned film, an increase in this distance is abnormal and may represent a hip effusion, infolded labrum after dislocation or intra-articular loose body entrapment after dislocation. Fibrofatty tissue within the joint (acetabulum pulvinar), septic arthritis and Perthes disease may also give similar findings. 

The most common complications of total hip replacement are aseptic resorption of bone with subsequent mechanical loosening and infection. Both conditions are associated with an effusion located inside the pseudocapsule of the joint. US can detect fluid collections as hypoanechoic areas with irregular borders located anteriorly to the femoral prosthetic neck on transverse oblique images (Fig. 12.62) (Foldes et al. 1992,1995). A distension of the pseudocapsule of greater than 3.2 mm at the native lateral femoral neck has been indicated as an indicator of infection (Fig. 12.63) (van Holsbeeck et al. 1994). Nevertheless, a more recent study questioned the... 

---