The two bones most commonly broken when the wrist is fractured are the scaphoid, a cashew-shaped structure adjacent to the bases of the thumb and forefinger, and the radius, the larger of the two forearm bones that connect to the wrist. Sometimes there are small fragments of bone that stay within the joint after a bone breaks, and these need to be removed, or the bones may need to be aligned and stabilized with pins, wires or screws. If stabilized externally, it is called external fixation. If stabilized internally, it is called internal fixation.
The scaphoid is particularly vulnerable to fracture in young, active patients. Scaphoid fractures in the wrist can be realigned with the assistance of the arthroscope. Treatment begins with external fixation of the bone, using threaded pins and a frame. The orthopaedic surgeon then uses the arthroscope and small instruments to realign the joint fragments and removes any small fragments of bone that may have broken loose. The surgeon works through a needle puncture of the skin, rather than through an open incision to insert the stabilizing instrument. A fluoroscopy, or real-time, moving X-ray, helps guide the surgeon’s placement of the pin or wire.
If the scaphoid fails to heal, a bone graft might be the next step. The graft’s blood supply must be continued and ensured at its new location to keep the bone healthy and growing.
Bone grafts (or more recently, bone graft substitutes) may be used to fill any structural defects resulting from the break. Using a percutaneous technique, pins, wires or screws are inserted to hold the bone fragments in place during healing-a period of approximately six weeks.
Multiple surgical procedures exist to try to correct or, at the least, relieve the pain of a scaphoid bone that has collapsed or sustained other problems associated with the fractured bone not healing in alignment. These surgeries include reconstructing the scaphoid, removing some of the nearby carpal bones in the wrist to preserve wrist motion, or surgically fusing joints to relieve pain.