Objective ：To investigate the different ways of measuring the main axial strain during treatment with an external fixator and to find the suitable compression loaded by the external fixator at an early stage. Method...Objective ：To investigate the different ways of measuring the main axial strain during treatment with an external fixator and to find the suitable compression loaded by the external fixator at an early stage. Methods. Eighteen healthy big-ear rabbits were randomly divided into two groups according to different measuring methods： Group A and Group B. In Group A, a strain gauge was affixed to the external tibiai cortex with 502 glue, and in Group B, a bone cement-coated strain gauge was installed on the internal tibial cortex. Groups A and B were divided into two subgroups A1, A2 and B1, B2, respectively, according to the pressure of haft of and the same as the body weight. A Z-shaped left mid-shaft tibiai osteotomy was performed and fixed by an external fixator. Results： The scaler curves of Group A changed dramatically during the early stage. The trendlines of the internal and external cortex went consistently after reaching the stable stage while the latter strain value was higher than the former. The time for Group B reaching the stable stage was short, but its absolute strain value was less than that of Group A. Before they were pressed to the stable stage, the declined speed of Subgroup A1 was more slowly than that of Subgroup A2 while the results of Subgroups B1 and B2 were same. Group A had an ascending trend after it declined while Group B didn＇t have. After they reached the stable stage, both Subgroups A1 and A2 had a declining trend while Subgroup A2 was more quickly than Subgroup A1, Subgroup B1 was kept at a definite level while Subgroup B2 fluctuated. Conclusions： The axial strain under external fixator can be measured by bone cement coated-strain gauge in vivo. The data may suggest that half of the body weight load was suitable for external fixator.展开更多
Objective: To study the therapeutic effect of collapsed and comminuted distal radius fracture. Methods: Twenty-six patients with collapsed and comminuted distal radius fracture were hospitalized from July 1998 to June...Objective: To study the therapeutic effect of collapsed and comminuted distal radius fracture. Methods: Twenty-six patients with collapsed and comminuted distal radius fracture were hospitalized from July 1998 to June 2003. All fractures were treated by the methods of open reduction, sustained bone grafting and passing joint external fixator to restore the anatomic shape of distal radius. Results: All 26 cases were followed up, and the results showed that the fractures have been united radiographically. The joint surfaces were intact and there was no length discrepancy occurred in patient’s radius. The average volar tilt was 6° to 15° and the average ulnar tilt was 18° to 25°. According to the Dieust criterion, 19 cases were rated as excellent and 7 as good. Conclusions: The method that applying passing joint external fixator and bone grafting for the treatment of collapsed and comminuted distal radius fracture could maintain the stability of fracture and restore the length of radius and the intact of joint surface.展开更多
基金This study was funded by the important fund item of Scientific Committee in Hubei Province (No. 982P1510)
文摘Objective ：To investigate the different ways of measuring the main axial strain during treatment with an external fixator and to find the suitable compression loaded by the external fixator at an early stage. Methods. Eighteen healthy big-ear rabbits were randomly divided into two groups according to different measuring methods： Group A and Group B. In Group A, a strain gauge was affixed to the external tibiai cortex with 502 glue, and in Group B, a bone cement-coated strain gauge was installed on the internal tibial cortex. Groups A and B were divided into two subgroups A1, A2 and B1, B2, respectively, according to the pressure of haft of and the same as the body weight. A Z-shaped left mid-shaft tibiai osteotomy was performed and fixed by an external fixator. Results： The scaler curves of Group A changed dramatically during the early stage. The trendlines of the internal and external cortex went consistently after reaching the stable stage while the latter strain value was higher than the former. The time for Group B reaching the stable stage was short, but its absolute strain value was less than that of Group A. Before they were pressed to the stable stage, the declined speed of Subgroup A1 was more slowly than that of Subgroup A2 while the results of Subgroups B1 and B2 were same. Group A had an ascending trend after it declined while Group B didn＇t have. After they reached the stable stage, both Subgroups A1 and A2 had a declining trend while Subgroup A2 was more quickly than Subgroup A1, Subgroup B1 was kept at a definite level while Subgroup B2 fluctuated. Conclusions： The axial strain under external fixator can be measured by bone cement coated-strain gauge in vivo. The data may suggest that half of the body weight load was suitable for external fixator.
文摘Objective: To study the therapeutic effect of collapsed and comminuted distal radius fracture. Methods: Twenty-six patients with collapsed and comminuted distal radius fracture were hospitalized from July 1998 to June 2003. All fractures were treated by the methods of open reduction, sustained bone grafting and passing joint external fixator to restore the anatomic shape of distal radius. Results: All 26 cases were followed up, and the results showed that the fractures have been united radiographically. The joint surfaces were intact and there was no length discrepancy occurred in patient’s radius. The average volar tilt was 6° to 15° and the average ulnar tilt was 18° to 25°. According to the Dieust criterion, 19 cases were rated as excellent and 7 as good. Conclusions: The method that applying passing joint external fixator and bone grafting for the treatment of collapsed and comminuted distal radius fracture could maintain the stability of fracture and restore the length of radius and the intact of joint surface.
