A fall on an outstretched arm often results in a fracture of the scaphoid (navicular) bone in the wrist. This small bone is one of 8 carpal bones in the wrist. The scaphoid sits below the thumb, and is shaped like a kidney bean. This complex bone has a unique and limited blood supply that can be easily disrupted by a fracture. The scaphoid’s blood flow comes from a small vessel that enters the most distant part of the bone and flows back through the bone to give nutrition to the bone cells. Because there is only this one, small blood supply, a fracture in the center of the bone can actually sever blood flow to the proximal portion of the bone. For this reason, scaphoid fractures need immediate diagnosis and treatment. Scaphoid fractures may heal very slowly or may not heal at all.
Diagnosis
If you have pain or deep aching on the thumb-side of the wrist, typically after a fall on an outstretched arm, you may have a scaphoid fracture. Other symptoms include swelling in the wrist, difficulty gripping objects, and tenderness or pain in the anatomical snuff box (a sunken space between tendons of the wrist). Many patients are diagnosed with a wrist sprain, when they actually have a fracture. Diagnosis is difficult because the fracture often doesn't appear on x-rays until weeks later, after healing has begun. Because of this, it is common for physicians to treat a wrist injury as though it were a scaphoid fracture initially, and then repeat x-rays within two weeks.
Treatment
If it is a simple, nondisplaced fracture, orthopedists usually treat the injury with cast immobilization to see if the fracture heals in a timely manner. Repeat x-rays are taken over several weeks or months, and the physician can watch for appropriate healing, which can take 10 to 12 weeks. If it does not heal, surgery can be considered.
If the scaphoid fracture is displaced, the risk of nonunion is higher, and your physician may recommend initial surgery to reposition the bones. Also, if the fracture does not heal with cast treatment (immobilization), surgery will be recommended. This type of surgery involves pinning the bone in place with screws. Sometimes a bone graft may also be used. A cast is used to immobilize the scaphoid bone after surgery.
Rehab
Rehabilitation is an important part of healing due to the long immobilization time needed to treat most scaphoid fractures. Range-of-motion exercises for the wrist can be started after immobilization, followed by strengthening exercises for the wrist flexors and extensors. Supination, pronation, and grip exercises should also be added.
Prevention
The best way to avoid a scaphoid fracture is to use proper protective gear whenever possible. Wrist guards are particularly useful during sports such as rollerblading, snowboarding and many contact sports.
