The Developments and Biomechanical Evaluations of New Wire-Locked Devices

• Main Authors: Chih-Hsun Chien, 簡志訓
• Other Authors: Jui-Hsiang Hsieh
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/61346517277389116176

碩士 === 中原大學 === 醫學工程研究所 === 97 === The tension band wiring technique is accepted worldwide in the operative treatment of many fracture around joints. It provided secure stability in fracture fixation. The method essentially involves placing a figure-of-8 wire loop over the tension side of the fracture. Besides, two Kirscher wires were frequently placed into the fracture site. The two pins are used to act as an internal splint neutralizing rotational and bending displacement forces. The wire loop is used to act as a tension band to convert the distractive and shear forces tending to separate the fragment into compressive forces across the fracture site. However, in clinical observation, back-out of the Kirschner wires is a common complication that made patient discomfort and pain. The purpose of this study is to design a wire-self-locking screw-pin to prevent the back-out of the pins. This design will prevent of this complication and provide rigid fixation to allow early mobilization that quickly restores functional status. Besides, this new pin can also be applied in fixation of distal radial fracture. Usually we fixed distal radial fracture with percutaneous pinning. Pin-tract infection and back-out of pins were the common problems. The new pin can avoid these problems by burying the head of the pin into skin. The study also provides a biomechanical evaluation of this new-design pin before clinical application. According to the results of our tests, the bending stiffness of the whole construct after fracture fixation with new pin is better than that of using the Kirscher wire. The pull-out strength of this new pin is much better than the Kirscher wire. This study demonstrates that this new pin can provide enough and greater strength in fixation of tension band wiring and distal radial fracture. Besides, the concept of the new pin can avoid the potential risk of complications of back-out of the pins and pin-tract infection.