Based on the nonlinear geometry field theory of continuum mechanics. this paper analyses the stress field due to a serew dislocation in an infinite an infinite medium . The results reveal the high-order effect of the ...Based on the nonlinear geometry field theory of continuum mechanics. this paper analyses the stress field due to a serew dislocation in an infinite an infinite medium . The results reveal the high-order effect of the stress field. When this effect is small. the result can be reduced to one of the classical linear elasticity. The body couple field of the serew dislocation is also investigated in this paper. The analytiecal expression of the body couple due to a serew dislocation is obtained with small rotation deformation. As the application of theoretical results. the stress and the body couple at the interface of the crystals are calculated when the serew dislocation is near the interface .展开更多
目的比较动力髋螺钉(dynamic hip screw,DHS)和空心加压螺钉(cannulated compression screw,CCS)治疗新鲜股骨颈骨折的临床疗效。方法回顾性比较我院2012年1月~2016年6月采用DHS或CCS内固定治疗且随访满1年的91例新鲜股骨颈骨折的资料,...目的比较动力髋螺钉(dynamic hip screw,DHS)和空心加压螺钉(cannulated compression screw,CCS)治疗新鲜股骨颈骨折的临床疗效。方法回顾性比较我院2012年1月~2016年6月采用DHS或CCS内固定治疗且随访满1年的91例新鲜股骨颈骨折的资料,DHS组44例,CCS组47例。比较2组手术时间、术中出血、术后负重时间、髋关节Harris评分、术后股骨头坏死及股骨颈短缩等并发症。结果手术时间DHS组[中位数74.5(45~342)min]长于CCS组[中位数50.0(13~138)min](Z=-5.560,P=0.000),术中出血DHS组[中位数77.5(10~1500)ml]多于CCS组[中位数10.0(2~400)ml](Z=-7.526,P=0.000),但术后1~7天可部分负重的比例DHS组[65.9%(29/44)]显著高于CCS组[38.3%(18/47)](χ2=6.938,P=0.008)。2组术后完全负重时间、影像学愈合时间、股骨头坏死、股骨颈短缩、骨折延迟愈合及Harris评分均无统计学差异(P>0.05)。随访时间13~66个月,2组均无内固定脱出、骨折不愈合,均无深静脉血栓、肺炎、肺栓塞等长期卧床并发症。结论在新鲜股骨颈骨折内固定治疗上,DHS及CCS均能坚强固定股骨颈骨折使髋关节功能得到良好恢复,二者在术后相关并发症上无统计学差异。DHS内固定术后患肢负重更早,利于患肢功能锻炼。对于不稳定型骨折及严重骨质疏松者,推荐使用DHS内固定系统。展开更多
文摘Based on the nonlinear geometry field theory of continuum mechanics. this paper analyses the stress field due to a serew dislocation in an infinite an infinite medium . The results reveal the high-order effect of the stress field. When this effect is small. the result can be reduced to one of the classical linear elasticity. The body couple field of the serew dislocation is also investigated in this paper. The analytiecal expression of the body couple due to a serew dislocation is obtained with small rotation deformation. As the application of theoretical results. the stress and the body couple at the interface of the crystals are calculated when the serew dislocation is near the interface .
文摘目的比较动力髋螺钉(dynamic hip screw,DHS)和空心加压螺钉(cannulated compression screw,CCS)治疗新鲜股骨颈骨折的临床疗效。方法回顾性比较我院2012年1月~2016年6月采用DHS或CCS内固定治疗且随访满1年的91例新鲜股骨颈骨折的资料,DHS组44例,CCS组47例。比较2组手术时间、术中出血、术后负重时间、髋关节Harris评分、术后股骨头坏死及股骨颈短缩等并发症。结果手术时间DHS组[中位数74.5(45~342)min]长于CCS组[中位数50.0(13~138)min](Z=-5.560,P=0.000),术中出血DHS组[中位数77.5(10~1500)ml]多于CCS组[中位数10.0(2~400)ml](Z=-7.526,P=0.000),但术后1~7天可部分负重的比例DHS组[65.9%(29/44)]显著高于CCS组[38.3%(18/47)](χ2=6.938,P=0.008)。2组术后完全负重时间、影像学愈合时间、股骨头坏死、股骨颈短缩、骨折延迟愈合及Harris评分均无统计学差异(P>0.05)。随访时间13~66个月,2组均无内固定脱出、骨折不愈合,均无深静脉血栓、肺炎、肺栓塞等长期卧床并发症。结论在新鲜股骨颈骨折内固定治疗上,DHS及CCS均能坚强固定股骨颈骨折使髋关节功能得到良好恢复,二者在术后相关并发症上无统计学差异。DHS内固定术后患肢负重更早,利于患肢功能锻炼。对于不稳定型骨折及严重骨质疏松者,推荐使用DHS内固定系统。
