A 15-year-old boy presents to the emergency department with a complaint of left wrist pain following a fall from his skateboard earlier in the day. The patient broke his fall with both arms extended in front of him and now complains of severe pain to the lateral aspect of his left wrist. Imaging studies confirm a hairline fracture to one of the carpal bones, commonly a site for trauma-induced avascular necrosis.
Which of the following carpal bones has most likely been fractured in this patient?
- A) Capitate
- B) Hook of hamate
- C) Lunate
- D) Scaphoid
- E) Trapezium
D) Scaphoid
The scaphoid is the carpal bone located in the proximal row and most lateral position. A mechanism of injury such as the one described here may lead to avascular necrosis, as a fracture to the scaphoid bone often interrupts blood supply from the radial artery. Initial imaging may be negative, and a fracture in that area should be presumed until proven otherwise because of the risk for poor healing and avascular necrosis.
Key Learning Point
Scaphoid fractures typically occur from a fall onto an outstretched hand. The scaphoid is the largest bone of the proximal carpal row and is located on the radial aspect of the hand just distal to the radius itself. The palmar carpal branch of the radial artery supplies the scaphoid via the bone's distal pole and then proceeds to the proximal pole. Blood supply to the proximal pole is tenuous and can be interrupted by a fracture which can lead to avascular necrosis.
