American Board of Surgery Qualifying Exam (ABS QE) Practice Test

What is a potential vascular injury associated with posterior knee dislocation?

1. Femoral artery

2. Popliteal artery

3. Radial artery

4. Subclavian artery

The correct answer is: Popliteal artery

A posterior knee dislocation primarily results in the displacement of the tibia relative to the femur, creating the potential for significant vascular compromise in the area. Among the vascular structures in the vicinity, the popliteal artery is the most vulnerable to injury during this type of dislocation. The popliteal artery runs behind the knee and is relatively exposed to mechanical forces when dislocations occur. The tension and disruption of soft tissues surrounding the knee joint can lead to traumatic occlusion or laceration of the popliteal artery. This can result in significant complications such as limb ischemia if not promptly recognized and treated, emphasizing the critical relation between posterior knee dislocation and potential popliteal artery injury. In contrast, while the femoral artery supplies the leg, its injury is more commonly associated with hip or proximal femur injuries rather than posterior knee dislocations. The radial and subclavian arteries are anatomically distant from the knee joint, making them less relevant in this specific scenario. Thus, the popliteal artery stands out as the primary structure of concern regarding vascular injury associated with posterior knee dislocation.