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A scaphoid fracture, a fracture of the scaphoid bone also known as the carpal navicular, is the most common type of carpal bone fracture.〔(【引用サイトリンク】title=eMedicine – Wrist, Scaphoid Fractures and Complications : Article by Carol A Boles )〕 Scaphoid fractures usually cause pain at the base of the thumb accompanied by swelling in the same area. Scaphoid fractures usually cause pain and sensitivity to palpation in the anatomic snuffbox at the base of the thumb accompanied by swelling in the same area. These are also called navicular fractures (the scaphoid also being called the carpal navicular) as navicular is the traditional name for the scaphoid bone, although this can be confused with the navicular bone in the foot. Treatment depends on the location of the fracture. Fractures of scaphoid can occur either with direct axial compression or with hyperextension of the wrist, such as a fall on the palm on an outstretched hand (FOOSH). The most common classification of scaphoid fractures categorizes them by location: distal third (distal pole), central third (waist) and proximal third (proximal pole)〔(Scaphoid fractures ) -Uptodate.com 〕 using the Herbert classification system. ==Diagnosis== Clinically patients present with ''snuff box'' tenderness. Focal tenderness is usually present in one of three places: 1) volar prominence at the distal wrist for distal pole fractures; 2) anatomic snuff box for waist or midbody fractures; 3) distal to Lister's tubercle for proximal pole fractures. 〔http://www.uptodate.com/contents/scaphoid-fractures?source=search_result&search=scaphoid+fracture&selectedTitle=1%7E18〕 Scaphoid fractures are often diagnosed by X-rays. However, not all fractures are apparent initially. Therefore, people with tenderness over the scaphoid (those who exhibit pain to pressure in the anatomic ''snuff box'' ) are often casted for 7–10 days at which point a second set of X-rays is taken. If there was a hairline fracture, healing will now be apparent. Even then a fracture may not be apparent. A CT Scan can then be used to evaluate the scaphoid with greater resolution. Fractures can take between 6 and 12 weeks of casting to heal. The Scaphoid receives its blood supply primarily from lateral and distal branches of the radial artery. Blood flows from the top/distal end of the bone in a retrograde fashion down to the proximal pole; if this blood flow is disrupted by a fracture, the bone may not heal. Surgery is necessary at this point to mechanically mend the bone together. The use of MRI, if available, is preferred over CT and can give one an immediate diagnosis. Bone scintigraphy is also an effective method for diagnosis fracture which do not appear on Xray. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Scaphoid fracture」の詳細全文を読む スポンサード リンク
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