A 68-year-old woman exhibits swelling and pain in her right wrist after a fall. What is the most likely diagnosis?

The most likely diagnosis for a 68-year-old woman who exhibits swelling and pain in her right wrist after a fall is a fracture of the distal radius. This condition is particularly common among older adults due to decreased bone density, which increases the risk of fractures with minimal trauma, such as a fall.

In this scenario, the mechanism of injury is critical. Falls are a common cause of wrist injuries, especially when individuals attempt to catch themselves with an outstretched hand. This typically leads to fractures in the distal radius, often resulting in a characteristic dorsal angulation or displacement known as a Colles' fracture. The swelling and pain observed in the wrist are characteristic symptoms following such an injury.

While other options present various wrist injuries, they do not align as directly with the common presentation following a fall in an elderly patient. Avascular necrosis of the scaphoid is less likely immediately following trauma and usually presents more subtly over time with specific pain. Dislocation of the first proximal phalanx, while possible, is less common than a distal radius fracture in the case of a fall. Avulsion of the ulnar styloid process might occur but is also less frequently the primary injury in this context.

Overall, the presentation of swelling and pain