What is the most common site for a proximal humeral fracture?

The surgical neck of the humerus is the most common site for a proximal humeral fracture. This area is particularly vulnerable due to its anatomical location and the biomechanical forces acting upon it. The surgical neck is situated below the tubercles and the greater tubercle itself, making it a frequently injured section during falls or direct trauma, especially in older adults.

Injuries to this site often result from mechanisms such as low-energy falls, which are common in the elderly population. This region’s vulnerability to fractures can also be attributed to its relatively thin cortex compared to other areas of the humerus, leading to a higher incidence of fractures under stress or impact.

The other sites mentioned, like the greater tubercle or intertubercular groove, although they can be fractured, are less commonly involved than the surgical neck. The capitulum, being part of the elbow joint, relates more to injuries around the elbow rather than the proximal humerus specifically. Therefore, the surgical neck's anatomical and biomechanical characteristics make it the most likely site for proximal humeral fractures.