tailieunhanh - báo cáo hóa học:" The use of twin-ring Ilizarov external fixator constructs: application and biomechanical proofof principle with possible clinical indications"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học quốc tế đề tài : The use of twin-ring Ilizarov external fixator constructs: application and biomechanical proofof principle with possible clinical indications | âMn JOURNAL OF ORTHOPAEDIC KRhl SURGERY AND RESEARCH wy The use of twin-ring Ilizarov external fixator constructs application and biomechanical proof-of principle with possible clinical indications Grivas and Magnissalis Grivas and Magnissalis Journal of Orthopaedic Surgery and Research 2011 6 41 http content 6 1 41 11 August 2011 BioMed Central Grivas and Magnissalis Journal of Orthopaedic Surgery and Research 2011 6 41 http content 6 1 41 JOURNAL OF ORTHOPAEDIC SURGERY AND RESEARCH RESEARCH ARTICLE Open Access The use of twin-ring Ilizarov external fixator constructs application and biomechanical proof-of principle with possible clinical indications Theodores B Grivas1 and Evangelos A Magnissalis2 Abstract Background In peri- or intra-articular fractures of the tibia or femur the presence of short metaphyseal bone fragments may make the application of an Ilizarov external fixator IEF challenging. In such cases it may be necessary to bridge the adjacent joint in order to ensure stable fixation. The twin-ring TR module of circular external fixation is proposed as an alternative method that avoids joint bridging without compromising stability of fixation. The aim of this study is to present the experimental tests performed to compare the biomechanical characteristics of the single- and TR IEF modules. The clinical application of the TR module in select patients is also presented and the merits of this technique are discussed. Methods In this experimental study the passive stiffness and stability of the single-ring SR and twin-ring TR IEF modules were tested under axial and shear loading conditions. In each module two perpendicular wires on the upper surface and another two wires on the lower surface of the rings were used for fixation of the rings on plastic acetal cylinders simulating long bones. Results In axial loading the main outcome measure was stiffness and the SR module proved stiffer than the TR. In shear loading the