Final answer:
A scaphoid fracture may not be visible on an X-ray immediately due to tissue swelling, but can be seen on a repeat radiograph after several weeks. Poor blood supply to the scaphoid bone can slow down healing and lead to complications.
Step-by-step explanation:
A scaphoid fracture may not show on an X-ray immediately after the injury, often leading to a misdiagnosis of a wrist sprain. This is because the fracture may not be visible due to tissue swelling. However, when the swelling subsides several weeks after the injury, a repeat radiograph can reveal the fracture. The scaphoid bone has a poor blood supply, which can slow down the healing process and increase the risk of bone necrosis and degenerative joint disease of the wrist.