What is it?
The scaphoid, also referred to as the navicular, is one of the eight small bones of the wrist, known as carpal bones. This particular bone gets its name from its shape, which is like a ship. Located on the thumb-side (radial side) of the wrist, the scaphoid can be fractured after a fall onto the hand.
What are the symptoms?
Pain along the radial aspect of the wrist just below the thumb is the most common presenting complaint of patients with acute (recent) scaphoid fractures. Movement of the wrist and thumb as well as weight-bearing through the hand may increase the pain. Occasionally, scaphoid fractures are not terribly painful and may go undetected for some time. In this case, they typically do not heal, developing into a nonunion. This problem can lead to arthritis of the wrist and radiocarpal joint. In this instance, pain may be more generalized around the wrist.
How is it evaluated?
Point tenderness directly over the scaphoid in an area known as the "snuff box" is suggestive of a scaphoid fracture. X-ray examination of the wrist is performed with specific views to fully visualize the scaphoid. Some scaphoid fractures are non-displaced and difficult to diagnose on routine x-rays. In this instance, a bone scan or MRI may be ordered. In the case of scaphoid nonunions or displaced fractures, a CT scan may be needed to assist with planning of operative treatment.
How is it treated?
Nondisplaced, acute scaphoid fractures may be successfully treated in a cast, however, they may take up to 16 weeks to heal. Another treatment option entails the placement of a screw into the scaphoid. With this treatment method, the time needed to be in a cast is limited to 2-4 weeks. After the cast is removed, a removable splint is worn until the fracture shows evidence of healing (6-8 weeks).
Displaced fractures have a high rate of not healing (nonunion), therefore, they require operative treatment. Usually this is performed using a screw as mentioned above. Occasionally, there is a need for a bone graft, which may be taken from the distal radius or the pelvis.
Scaphoid nonunions require operative intervention, as arthritis is likely to develop if left untreated. Bone grafting is frequently needed to address this problem. Post-operative immobilization may also be longer than with an acute fracture.