1. The scaphoid bone is located in the snuffbox
The scaphoid sits on the radial aspect of the proximal carpal row. Make a "thumbs-up" sign, with your fingers closed into a fist and the thumb pointing straight up. Now move your thumb left and right and in a circle. You will notice a depression between some tendons, which is called the anatomic snuffbox. If you push down in the depression, you will be palpating the scaphoid bone. The snuffbox gets its name from the fact that people would put snuff, or tobacco, there and then snort it.
2. They usually occur due to a fall on an outstretched hand
When people fall, they usually stretch out their hands to help break the fall. This usually causes their wrists to be bent backward, or extended. Also, the wrists tend to be radially deviated, meaning that the hand is pushed toward the thumb from the momentum of the fall. In this position, the scaphoid can become trapped between the distal radius and the rest of the hand, causing it to fracture. More commonly the distal radius will fracture (see wrist fractures). But depending on the exact position of the hand, the scaphoid can also break. As a result of this, scaphoid fractures are the most common carpal bone fracture.
3. Wrists braces can help prevent these fractures
Wrist guards can prevent these types of fractures. They usually have some sort of metal piece extending from the forearm to the palm. The purpose of this is to prevent the wrist from bending backward, which can help prevent scaphoid or distal radius fractures. These should be worn during activities in which there are frequent falls, such as rollerskating, rollerblading and snowboarding.
4. The scaphoid has a poor blood supply
Certain bones in the body have a poor blood supply. Unfortunately, the scaphoid is one of them. There are two reasons for this. Blood vessels need to pass directly into the bone itself, so they can't pass through cartilage. Most of the scaphoid is covered in cartilage. Also, most bones get their blood supply from the side of the bone closest to the heart. The scaphoid has a distally based blood supply. This means that the blood enters the bone from the side AWAY from the heart.
5. There is a high risk of avascular necrosis (AVN)
Because of the way the scaphoid receives its blood supply, it is at higher risk of getting avascular necrosis, or death of the bone. Most scaphoid fractures are waist fractures, right through the middle portion of the bone. When that happens, the proximal pole (part closest to the forearm), can have its blood supply cut off and not heal, or even die and collapse.
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