A scaphoid (navicular) fracture is a break in one of the small bones of the wrist. This type of fracture occurs most often after a fall onto an outstretched hand. Symptoms of a scaphoid fracture typically include pain and tenderness in the area just below the base of the thumb. These symptoms may worsen when you try to pinch or grasp something.
Treatment for a scaphoid fracture can range from casting to surgery, depending on the fracture’s severity and location on the bone. Because portions of the scaphoid have a poor blood supply—and a fracture can further disrupt the flow of blood to the bone—complications with the healing process are common.
The wrist is formed by the two bones of the forearm—the radius and the ulna—and eight small carpal bones. The carpal bones are arranged in two rows at the base of the hand. There are four bones in each row.
The scaphoid bone is one of the carpal bones on the thumb side of the wrist, just above the radius. The bone is important for both motion and stability in the wrist joint. The word “scaphoid” comes from the Greek term for “boat.” The scaphoid bone resembles a boat with its relatively long, curved shape.
The scaphoid bone can most easily be identified when your thumb is held in a “hitch-hiking” position. It is located at the base of the hollow made by the thumb tendons. Often referred to as the “anatomic snuffbox,” this area is typically the site of tenderness or pain when a fracture occurs.
A scaphoid fracture is usually described by its location within the bone. Most commonly, the scaphoid breaks in its mid-portion, called the “waist.” Fractures can also occur at both the proximal and distal ends of the bone.
Scaphoid fractures are classified according to the severity of displacement–or how far the pieces of bone have moved out of their normal position:
A scaphoid fracture usually occurs when you fall onto an outstretched hand, with your weight landing on your palm. The end of the larger forearm bone (the radius) may also break in this type of fall, depending on the position of the hand on landing.
The injury can also happen during sports activities or motor vehicle collisions.
Fractures of the scaphoid occur in people of all ages, including children.There are no specific risk factors or diseases that make you more likely to experience a scaphoid fracture. Some studies have shown that using wrist guards during high-energy activities like inline skating and snowboarding can help decrease your chance of breaking a bone around the wrist.
Scaphoid fractures usually cause pain and swelling in the anatomic snuffbox and on the thumb side of the wrist. The pain may be severe when you move your thumb or wrist, or when you try to pinch or grasp something.
Unless your wrist is deformed, it might not be obvious that your scaphoid bone is broken. With some scaphoid fractures, the pain is not severe and may be mistaken for a wrist sprain.
Pain in your wrist that does not go away within a day of injury may be a sign of a fracture—so it is important to see a doctor if your pain persists. Prompt treatment of a scaphoid fracture will help avoid potential complications.
During the exam, your doctor will talk with you about your general health and will ask you to describe your symptoms. He or she will want to know how your injury occurred.
Your doctor will examine your wrist. With most fractures, there will be tenderness directly over the scaphoid in the anatomic snuffbox. Your doctor will also look for:
X-rays. X-rays provide images of dense structures, such as bone. Your doctor will order an x-ray to help determine if you have a scaphoid fracture and whether the broken pieces of bone are displaced. An x-ray will also help your doctor determine if you have any other fractures.
In some cases, a scaphoid fracture does not show up on an x-ray right away. If your doctor suspects that you have a fracture but it is not visible on x-ray, he or she may recommend that you wear a wrist splint or cast for 2 to 3 weeks and then return for a follow-up x-ray. Often, scaphoid fractures become visible on x-ray only after a period of time. During this waiting period, you should wear your splint or cast and avoid activities that might cause further injury.
Magnetic resonance imaging (MRI) scan. Your doctor may order an MRI to learn more about the bones and soft tissues in your wrist. An MRI can sometimes show a fracture of the scaphoid before it can be seen on x-ray.
Computerized tomography (CT) scan. A CT scan can be helpful in revealing a fracture of the scaphoid and can also show whether the bones are displaced. Your doctor will use information from the CT scan to help determine your treatment plan.