Anatomy of the Scaphoid Bone of the Wrist
The scaphoid is one of the small bones of the wrist, located at the base of the thumb in the area where the wrist bends. When the thumb is held in a hitchhiking position, the scaphoid is at the base of the hollow made by the thumb tendons. Of the small bones in the wrist, it is the most likely to break and pain or tenderness in this area can be a sign it is injured.
Symptoms of a Scaphoid Fracture
Scaphoid fractures usually cause pain and swelling at the base of the thumb. The pain may be severe when you move your thumb or wrist, or when you try to grip something. In some cases, the pain is not severe and the fracture may be mistaken for a sprain, although a sprained wrist is actually quite rare. Unless your wrist appears deformed, it might not be obvious that this bone is broken. If the pain in your wrist does not subside within a day of the injury, it may be a sign of fracture. If symptoms persist, it is very important to seek medical care.
What Causes a Fracture of the Scaphoid Bone?
Fractures of the scaphoid occur in people of all ages. This fracture often happens as a person tries to break a fall and lands on an outstretched hand with the palm bearing most of the weight. Automobile accidents and sports injuries are also frequent causes. Wrist guards may offer some protection during activities like inline skating or snowboarding. There are no specific diseases or risks that increase the chances of fracturing the scaphoid.
Diagnosing a Fractured Scaphoid
An X-ray can reveal if the bone is fractured and whether there is displacement (a gap between broken bones). Because a scaphoid fracture does not always show up on X-ray immediately, your physician may place your wrist in a splint and have you return for another X-ray after a week or two have passed to see if the fracture becomes visible. During this waiting period, heavy lifting should be avoided and the splint should be worn continuously. Your physician may also choose to use an MRI (magnetic resonance Image) to visualize the wrist bones and surrounding tissues, as this option can sometimes reveal a fracture of the scaphoid before it can be seen on an X-ray.
Nonsurgical Treatment
Treatment will depend on the exact location of your fracture. Near the thumb, the bone has a good supply of blood necessary for healing, so scaphoid fractures in this area usually mend in a matter of weeks with proper protection. If the fracture is in the middle of the bone (waist) or closer to the forearm (proximal pole), healing can be more difficult because these areas of bone have a less efficient blood supply. Your arm and hand will remain in a cast during the healing period. Whether or not the cast extends above the elbow or involves your thumb will depend on where the scaphoid fracture has occurred.
Surgery
If your scaphoid is fractured at the waist or proximal pole, your physician may recommend surgery so that metal implants such as screws and wires can be used to hold the bone firmly in place until it is fully healed. If your bone is in more than two pieces, or if it fails to mend as expected, a bone graft may be needed to aid in proper healing. During this procedure, the bone to be used for your graft may be taken from your forearm in the same arm as the break, or less frequently, from your hip. This graft of new bone will be placed around the areas of broken bone to stimulate healing and increase bone production, helping the fractured bones to heal together into solid bone.
Recovering From a Scaphoid Fracture
A cast or splint will be required for as long as 12 weeks, depending on the fracture location, and whether operative or nonoperative treatment was chosen. During this healing period, you should expect many restrictions, such as: no use of your injured arm for heavy lifting, carrying, pushing, pulling or throwing; no participation in contact sports; no climbing ladders or trees; no activities that increase your risk of falling onto the hand, including inline skating or jumping on a trampoline.
Proper healing depends on your complete adherence to all of your physician’s instructions. It is very important for you to maintain full finger motion throughout the recovery period. Your doctor will provide you with an exercise program and may also recommend hand therapy to help you regain as much motion and strength in your wrist as possible.