What is the Morgan line in canine hip dysplasia?

• A. Fracture line in pelvis
• B. Narrowed acetabular cup
• C. Osteophyte formation on neck of femur
• D. Luxation of the hip

Answer: (C)

In hip dysplasia, ongoing joint instability triggers degenerative changes that produce bone spurs, and the Morgan line is the radiographic marker of that process along the neck of the femur. It appears as a thin, irregular radiopaque line where osteophytes form at the femoral neck, reflecting osteoarthritis rather than an acute injury. This makes it distinct from a fracture line, which would show a complete break in continuity, a narrowed acetabular cup which describes socket remodeling rather than a linear osteophyte, or aluxation, which is a displaced joint. So the Morgan line is the osteophyte formation on the femoral neck associated with degenerative changes in canine hip dysplasia.