Fixation of fractures of the hand with resorbable tapered pina biomechanical study

Objective To study biomechanical characteristics of resorbable tapered pin,and to investigate the feasibility of using for fixation of fracetures of the hand. Methods Sixteen pairs of fresh frozen human cadaveric metacarpal and proximal phalangeal bones were utilized.An oblique osteotomy was made at an angle of appropriately 45°to the long axis of the bone,and the bone was then fixed with two 1.0 mm K-wires or two resorbable tapered pins.Bending and fatigue testing were performed to obtain biomechanical data. Results ?The bending rigidity and the maximal load of resorbable taoered pin was significantly lower than that of K-wire. After fatigue testing,the maximal load and the displacement of resorbable tapered-pin was significantly lower than that of K-wire,while the bending rigidity is not statistically different between two materials.The maxinal load ratio of resorbable tapered pin to K-wire was significantly higher after fatigue testing, but the bending rigidity ratio was not statistically different. Conclusion The rigidity of resorbable tapered pin was lower than that of K-wire, but still strong enough to counteract the stress caused by postoperative rehabilitation.Resorbable tapered pin has great flexibility and is superior to K-wire during postoperative exercise. Key words: Hand; bones; Fractures bone; Biomechanics; Resorbable tapered pin