American Board of Surgical Assistants (ABSA) Orthopedic Practice Test

Intercondylar fractures of the lower humerus usually result from which of the following?

1. Direct blow to the shoulder

2. Blow or fall directly on the elbow

3. Twisting motion of the arm

4. Fall on an outstretched hand

The correct answer is: Blow or fall directly on the elbow

Intercondylar fractures of the lower humerus typically occur due to a blow or fall directly on the elbow. This injury is characterized by the unique anatomical structure of the elbow joint, where significant force applied to the area can lead to fractures in the critical region between the two condyles of the humerus. The impact directly affects the elbow joint, causing a fracture to the intercondylar region, which can destabilize the joint and impair its function. While other mechanisms like falls on an outstretched hand might contribute to different types of injuries in the upper limb, they are less specific to intercondylar fractures. A direct blow to the shoulder or a twisting motion of the arm would not typically isolate the forces to the region of the humerus in a manner that would result in intercondylar fractures. Thus, the specific nature of the impact to the elbow area is paramount in understanding the cause of such fractures.