Ultrasound-guided hip joint injection

Ultrasound has many advantages over other imaging modalities, including portability, lack of ionizing radiation and real-time visualization of soft tissues and neurovascular structures.

Many studies have demonstrated the safety, accuracy and efficacy of ultrasound-guided techniques,[2] although there is lack of standardization regarding the injectates used and long-term benefit remains uncertain.

The use of a high-frequency (> 10 MHz) linear array transducer is recommended, but lower-frequency curvilinear probes may be occasionally required to visualize deep structures in larger patients.

A preliminary diagnostic sonographic examination, including color Doppler of the area to be punctured is necessary to define the relationship of adjacent neurovascular structures.

[1] Injections should be performed with adherence to aseptic technique although this varies between institutions and radiologists attributable to resources, training, perceived risk and experience.

[1] Two common anterior approaches are typically used both with the patient lying supine: Initial treatment options include activity modification, analgesia and physical therapy.

Intra-articular hip injections can be technically challenging due to depth, variable body habitus, and the proximity to the femoral neurovascular bundle.

Fluoroscopic-guidance was the mainstay imaging-guidance hip injection, but ultrasound-guidance is becoming increasingly prevalent due to its accuracy with visualization of soft tissue and neurovascular structures, less associated cost and no ionizing radiation exposure or risk of contrast agent reactions.

A position statement by the American Medical Society for Sports Medicine reviewed the literature and found several level one studies of ultrasound guided hip injections with a mean accuracy of 99%.

Anterior longitudinal approach. An arrow parallel to the long axis of the transducer is drawn on the skin adjacent to the end of transducer where the needle will be introduced. [ 1 ]
Anterior longitudinal approach. The needle is introduced from an inferior and anterior approach, lateral to the femoral neurovascular bundle (arrow). A, acetabulum; H, femoral head; N, femoral neck; double arrow – anterior joint recess. [ 1 ]
Anterolateral approach, here shown as a transverse image. The needle will rest on the femoral head (arrow). A, acetabulum; H, femoral head; N, femoral neck; LAT, lateral; MED, medial. [ 1 ]