橈骨遠位端骨折における遠位骨片安定化に寄与する手関節固定肢位

（有限要素シミュレーションと解剖体を用いた力学的評価）

抄録

Colles’ fracture is a common injury that tends to result in dorsal displacement of the bone fracture fragment of the distal radius. Most wrist fractures can be treated with closed reduction and wrist immobilization in a specific position to restore the displacement. However, the most effective position of wrist immobilization remains controversial. In this paper, we used a cadaveric and computational approach to reveal an effective position concerning pressure on a dorsal surface of the distal radius as a stability factor during wrist immobilization. Cadaver wrists containing a force sensor were prepared, and a numerical simulation model was constructed to determine the relationship between pressure on the distal radius and various wrist positions. The major contributing factors for putting pressure on the distal radius were the abductor pollicis longus and extensor pollicis brevis. The position that exerted a strong force on the distal radius was determined by considering the direction of the reaction force vector: pronation and ulnar deviation without flexion/dorsiflexion, with slight palmar flexion and with slight dorsiflexion. The cadaveric and computational method shown here is the first to identify the most effective position for wrist immobilization concerning the mechanical force on the dorsal surface of the distal radius. The optimal immobilization position in terms of contact force can be determined for each patient depending on the fracture type and specific patient physical characteristics by the constructed simulation system which is capable of changing parameters of the numerical model.