A 25-year-old male athlete is admitted to the emergency depament after a bad landing in the pole vault. Radiographic examination of his hand reveals a fractured carpal bone in the floor of the anatomic snuffbox ( Fig). Which bone has most likely been fractured?
**Core Concept**
The anatomic snuffbox is a triangular deepening on the radial, dorsal aspect of the hand, bounded by the tendons of the extensor pollicis longus and extensor pollicis brevis muscles. It is located on the floor of the snuffbox and contains the radial artery and the tendons of the thumb.
**Why the Correct Answer is Right**
The bone most likely fractured in the floor of the anatomic snuffbox is the scaphoid bone. The scaphoid bone is the most commonly fractured carpal bone, and it is located in the floor of the anatomic snuffbox. The scaphoid bone is a wedge-shaped carpal bone that plays a crucial role in wrist motion and instability. It is prone to fractures due to its location and the mechanism of injury, such as a fall onto an outstretched hand.
**Why Each Wrong Option is Incorrect**
* **Option A:** The lunate bone is a midcarpal bone that is not typically located in the floor of the anatomic snuffbox. While it can be involved in various wrist injuries, it is not the most likely bone to be fractured in this location.
* **Option B:** The capitate bone is a midcarpal bone that is located more centrally in the carpal tunnel. It is not typically associated with fractures in the floor of the anatomic snuffbox.
* **Option C:** The trapezium bone is a carpal bone that is located in the thumb carpometacarpal joint. While it can be involved in various thumb injuries, it is not typically associated with fractures in the floor of the anatomic snuffbox.
**Clinical Pearl / High-Yield Fact**
The scaphoid bone is the most commonly fractured carpal bone, and it is often associated with a fall onto an outstretched hand. A high index of suspicion for scaphoid fractures is essential in athletes who participate in sports that involve landing from heights.
**Correct Answer:** D.