The In Vivo Study Of Three-dimensional Kinematics Of Fractured Scaphoid

【Objective】To accurately quantify three-dimensional in vivo kinematics of fractured scaphoid in wrist flexion-extension and radial-ulnar deviation,and to provide the theoretic proofs to clinical application.【Methods】The double wrists of 10 adult volunteers with scaphoid fracture were imaged by spiral CT at neutral posture and at 15°,30°,45°,60°postures during wrist flexion-extension motion and at 10°,20°postures during wrist radial deviation and at 10°,20°,30°,40°postures during wrist ulnar deviation.The 3D quantitative measurement and analysis of fractured scaphoid were performed in our computer-operated simulation system.The 3D kinematic data of the fractured scaphoid which were referred to the center of articular surface of distal radius can be measured.Then it was analyzed and compared with the kinematic data from the healthy scaphoid.【Results】1.After the scaphoid was fractured,being compared with the healthy scaphoid,the proximal fragment of scaphoid showed that the change of rotation and translation was not obvious,but the result of distal fragment of scaphoid was opposite.2.At the radial 10°and extensional 15°—30°position of the wrist,the distance between the centroids of distal and proximal fragment models was the smallest.3.At the radial 10°and extensional 15°position of the wrist,the distance between fractural lines was smaller than other positions.【Conclusions】To treat the scaphoid fracture,put the wrist at the position of extension and radial deviation in some sort,the distance between the fractural fragments was smaller and reestablishment of fracture was satisfactory.The study sufficiently provided some theoretic and technical reference for curing the disease of scaphoid fracture.