The Biomechanical Comparative And Clinical Study For Neotype Dynamic Hoffmann External Fixation In Tibial-fibular Fractures

1. The biomecbanical comparative study of three kinds of external fixation in tibial-fibular fractures.Objective: To investigate the biomechanics function of three kinds of external fixation in tibial-fibular fractures and provide evidence for clinical application. Methods: 15 tibial specimens of adult corpse treated with formaldehyde were photographed by X-ray to eliminate impairment and pathological changes, divided into three groups randomly, manufactured into the modle of oblique fracture in the mid part, and fixed with neotype dynamic Hoffmann , improved Hoffmann type and multifunctional external fixation respectively. After the biomechanical test, these different methods were compared and analysed.Results: The analysis proved that neotype dynamic Hoffmann and improved Hoffmann external fixation had no obvious difference in intensity, rigidity and stability(p>0.05), and had significant deviation with multifunctional external fixation (P<0.05). But the dodge rate of the neotype of dynamic Hoffmann had significant deviation with two other external fixation(P<0.05), hence the neotype of dynamic Hoffmann external fixation had more advantages than other methods. Conclusion: Neotype dynamic Hoffmann external fixation is superior biomechanicly.2. Anatomic research about the safe pin extent for external fixation of tibial-fibular fractures.Objective: To investigate the safety of pin extent for external fixation of tibial-fibular fractures.Methods: Tibia] specimens of adult corpses were undertaken angio-dissection andneurotomy. Schanz threaded pins were inserted from anteriomedial of tibia to backwardsand outside of bone crista which were selected upper .middle and inferior planesrespectively, and measured the safe angle of insertion to avoid injury of blood vessel andnerve.Results: The safe pin extent of tibial tubercle , mid-inferior segment and above 5cm ofankle joint surface were 140° ,120° ,120° correspondingly.Conclusion: The security of the external fixtion of tibial-fibular fractures can be significantimproved through choosing the safe pin extent.3. Clinical application research of two kinds of external fixation for opentibio-fibular fractures.Objective: To evaluate the effects of two kinds of external fixation devices for tibio-fibularfractures.Methods: 128 patients with open tibio-fibular fractures were reviewed from 1995 to 2004.AH patients were divided into two groups, which were treated by neotype dynamicHoffmann and improved Hoffmann external fixation respectively.Results: The bone healing time in the neotype dynamic Hoffmann external fixation groupwas shortened more significantly than that in the contrast group.Conclusion: Neotype dynamic Hoffmann external fixation can accelerate bone healing. Itis regarded a good method of external fixation.