[目的]观察骨骼发育成熟的单侧发育性髋关节完全脱位(unilateral developmental dislocation of the hip,UD-DH)的患者脱位侧下肢长度与膝关节畸形的变化特点。[方法]通过骨盆正位X线片及站立位双下肢全长X线片对骨骼发育成熟的UDDH(Har...[目的]观察骨骼发育成熟的单侧发育性髋关节完全脱位(unilateral developmental dislocation of the hip,UD-DH)的患者脱位侧下肢长度与膝关节畸形的变化特点。[方法]通过骨盆正位X线片及站立位双下肢全长X线片对骨骼发育成熟的UDDH(HartofilakidisⅡ或Ⅲ型)进行脱位侧股骨头上移距离、双侧下肢骨骼长度、小粗隆至内踝长度的测量,同时测量双侧膝关节外翻角。[结果]28位UDDH患者符合研究标准。平均年龄29.80岁(13.4～66.2岁)。脱位侧股骨头均上移,上移距离为4.6～60.9 mm,平均30.9 mm。脱位侧下肢骨骼长度延长者20例,占71.43%;最长延长距离为25 mm,平均延长9.4 mm;双侧对比有显著性差异,P=0.022。小粗隆至内踝尖的距离延长者24例,占85.71%;最长延长距离为29.3 mm,平均延长12.1 mm;双侧对比有显著性差异,P=0.000。脱位侧下肢骨骼长度延长5 mm以上者12例,占42.86%。脱位侧大于3°的膝外翻畸形12例,膝内翻1例;而非脱位侧大于3°的膝内翻畸形15例,膝外翻畸形1例;双侧对比有显著性差异,P=0.000。[结论]本研究通过骨盆正位及双下肢全长正位X线片显示UDDH患者脱位侧股骨头均明显上移;脱位侧骨骼长度较非脱位侧延长的比例高达70%,若以小粗隆为参考标志,脱位侧延长比例高达85.71%。脱位侧出现膝外翻畸形的发生率较高,而非脱位侧膝内翻的发生率高。展开更多
After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall （in excess of 1.5 km2 in plan）, doubts arose concerning the level of initial prestress and the stre...After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall （in excess of 1.5 km2 in plan）, doubts arose concerning the level of initial prestress and the strength and serviceability of the slabs was questioned. To assess the strength of the slabs, it was assumed, as a worst case scenario, that some spans may have been constructed with zero initial prestress. Load tests on prototype specimens, with similar dimensions and reinforcement quantities as the floor slabs, were performed to assess the stress development in initially unstressed, but fully grouted, tendons. Unexpected bond failures occurred at the junctions of slab and band beam where the abrupt change in section depth caused a sudden change in tendon stress. The maximum stress that was developed in the initially unstressed tendons at these locations was about 60% of the strength of the tendons.展开更多
目的测量并分析成人单侧发育性髋关节发育不良(developmental dysplasia of the hip,DDH)患者影像学下肢长度差异的特点。方法回顾分析2016年1月—2018年6月符合选择标准的112例单侧DDH患者临床资料。其中男16例,女96例;年龄20~76岁,平...目的测量并分析成人单侧发育性髋关节发育不良(developmental dysplasia of the hip,DDH)患者影像学下肢长度差异的特点。方法回顾分析2016年1月—2018年6月符合选择标准的112例单侧DDH患者临床资料。其中男16例,女96例;年龄20~76岁,平均42.9岁。DDH根据Crowe分型,Ⅰ型25髋、Ⅱ型26髋、Ⅲ型15髋、Ⅳ型46髋(其中无继发臼形成的ⅣA型26髋、有继发臼形成的ⅣB型20髋)。摄站立位下肢全长X线片,测量以下参数:大转子下肢长度(greater trochanter leg length,GTLL)、大转子股骨长度(greater trochanter femoral length,GTFL)、小转子下肢长度(lesser trochanter leg length,LTLL)、小转子股骨长度(lesser trochanter femoral length,LTFL)、胫骨长度(tibial length,TL)、大小转子间距离(intertrochanteric distance,ITD)。比较健患侧上述参数,并计算各参数健患侧差值;以健患侧差值5 mm作为阈值,分别统计上述参数健侧较患侧>5 mm(健侧长)以及患侧较健侧>5 mm(患侧长)的例数;比较各影像学参数健患侧差值在不同Crowe分型之间以及CroweⅣA型和ⅣB型之间的差异。结果健患侧GTLL和LTFL比较差异均无统计学意义(P>0.05);患侧LTLL和TL长于健侧,GTFL和ITD短于健侧,差异均有统计学意义(P<0.05)。TL、LTLL患侧长构成比大于健侧长构成比,而GTFL、ITD健侧长构成比大于患侧长构成比,GTLL和LTFL健侧长或患侧长构成比无明显差异。不同Crowe分型间比较显示,仅Ⅰ型和Ⅳ型间TL健患侧差值比较差异有统计学意义(P<0.05),其余各分型间各影像学参数健患侧差值比较差异均无统计学意义(P>0.05)。与CroweⅣB型比较,ⅣA型GTLL、TL和ITD健患侧差值较大,差异均有统计学意义(P<0.05);其余指标ⅣA型和ⅣB型间比较差异均无统计学意义(P>0.05)。结论成人单侧DDH患者双下肢不等长,差异主要来自于TL和ITD,术前规划时需注意这点。展开更多
文摘After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall （in excess of 1.5 km2 in plan）, doubts arose concerning the level of initial prestress and the strength and serviceability of the slabs was questioned. To assess the strength of the slabs, it was assumed, as a worst case scenario, that some spans may have been constructed with zero initial prestress. Load tests on prototype specimens, with similar dimensions and reinforcement quantities as the floor slabs, were performed to assess the stress development in initially unstressed, but fully grouted, tendons. Unexpected bond failures occurred at the junctions of slab and band beam where the abrupt change in section depth caused a sudden change in tendon stress. The maximum stress that was developed in the initially unstressed tendons at these locations was about 60% of the strength of the tendons.
