Dorsolateral approach to hip and pelvis ultrasound in dogs.

Abstract

OBJECTIVE: To provide a video tutorial demonstrating ultrasound of the canine hip and pelvis for identifying hip luxation and other pelvic injury. ANIMALS: Dogs presenting with acute pelvic limb lameness referable to the hip region. METHODS: The hip and abaxial portions of the pelvis are visualized in short-axis orientation by placement of a linear (5- to 14-MHz) or microconvex (4- to 10-MHz) ultrasound probe on the dorsolateral aspect of the pelvis in medial-lateral orientation. Clipping the haircoat and applying ultrasound gel allows for best visualization, though application of 70% isopropyl alcohol without clipping allows acceptable imaging of osseous structures in most dogs. Starting at the cranial extent of the iliac wing, the pelvis is imaged from cranial to caudal. Osseous structures are identified by their contours and acoustic shadowing. The normal hip joint is recognized by articulation of the rounded femoral head with the triangularly shaped contour of the acetabulum. RESULTS: Hip luxation is identified by displacement of the femoral head cranially or caudally to the acetabulum with either dorsal positioning of the femoral head or ventral positioning of the greater trochanter relative to adjacent pelvic bones. Fractures are detected through the presence of steplike defects in the osseous contours. CLINICAL RELEVANCE: Ultrasound of the pelvis and hip region in dogs allows for timely identification of hip luxation or pelvic fractures without sedation. This technique can be utilized in emergency, ambulatory, or remote care settings to help categorize injury for facilitating client discussions regarding additional imaging recommendations, treatment recommendations, and associated medical care costs.