第一部分： CT三维重建分析不同体位对股骨侧弓及股骨外翻角测量的影响

【目的】通过CT扫描数据重建下肢骨骼模型，测量下肢在不同的旋转角度下的股骨侧弓角（FBA）及股骨外翻角（VCA）等数值，探讨下肢不同旋转体位对二者测量结果影响的规律。

【材料与方法】筛选符合入选标准的患者，Mimics13.0软件对各个病例CT扫描数据重建出该肢体骨骼的三维立体模型，确认其标准正位，按照标准正位下FBA数值分为四组，A组FBA>2°，B 组2°≥FBA> 0°，C 组0 ≥FBA>-2°, D 组FBA≤-2°,每组5侧下肢，利用软件功能使该模型沿下肢纵轴以2°步幅精确旋转出自内旋20°至外旋20度的21个图像，由所得图像测量FBA及VCA。分析不同体位下FBA的及VCA变化的规律。

【结果】①各组病例标准正位FBA分别为A组2.49°±0.46°，B组1.06°±0.39°，C组-1.41°±0.49°和D组-3.49°±0.74°。②四组病例的FBA的变化规律显示，下肢内旋使FBA值呈减小趋势，下肢外旋使FBA呈加大趋势，四组的回归系数分别为A组0.47度/度，B组0.34度/度，C组0.33度/度，D组0.35度/度；③各组标准正位VCA均值分别为A组7.73°±1.27°，B组6.61°±1.03°，C组5.30°±1.15°，D组4.18°±1.37°，下肢外旋使VCA呈逐渐增大的趋势，下肢内旋使VCA呈逐渐减小的趋势。各组VCA与旋转度数的回归系数分别为A组0.1度/度，B组0.03度/度，C组0.04度/度和D组0.07度/度。④四组病例数据显示不同体位下的股骨侧弓与股骨外翻角相关系数r分别为：A组0.86，B组0.80，C组0.88组D组0.85，均呈显著正相关。

【结论】在下肢全长X线像上，FBA和VCA测量结果大小会随肢体外旋而逐渐增大，随肢体内旋逐渐减小，且侧弓程度越大，这种趋势越明显，所以为获得可信的临床资料，拍摄下肢正位全长X线片时应重视采用投照体位为标准正位，尤其对于股骨侧弓较大的病例。

第二部分  股骨侧弓角的个体差异及其对全膝人工关节置换术后下肢力线的影响

【目的】 通过对全膝人工关节置换术（TKA）术前患者标准下肢全长X线像股骨侧弓角（FBA）及股骨外翻角（VCA）以及术后股骨远端外侧角（LDFA）等数据的测量，得出它们数据的分布特点，分析它们之间的相关性及股骨侧弓对TKA术后下肢力线的影响。

【材料与方法】 收集我科自2013年1月至2015年12月间收治的接受TKA术前的病例，按照统一的纳入和排除标准，筛选出符合入选标准的病例699例共1000膝，在其标准正位下肢全长X线像测量股骨外翻角，股骨侧弓角，股骨近端偏心距，股骨长度，股骨颈干角以及术后股骨远端外侧角（LDFA）。所得数据进行如下分析：①FBA的均数及分布特点；②VCA的均数及分布特点；③分别分析VCA与股骨侧弓角、股骨近端偏心距、股骨长度，股骨颈干角四参数间的相关性；④按照FBA大小将病例分至A区间（FBA<-3°），B区间（-3°≤FBA≤0°），C区间（0°3°），以每一病例的VCA值分别直接减去5和6，来模拟分别按照股骨远端5°，6°外翻截骨的手术方案，所得结果LDFA代表术后股骨机械力线，以术后股骨机械力线偏离正常值小于2度认为结果理想，对比各截骨方案在各区间内理论的术后力线理想率。⑤按手术时股骨外翻截骨角度的不同分为第一组（固定5度外翻截骨），第二组（固定6度外翻截骨）和第三组（根据实际VCA决定截骨角度），以术后股骨机械力线LDFA偏离正常值小于2度认为结果理想，分别比较TKA术后各组在各FBA区间的力线理想率。

【结果】 ①测量FBA所得均值为1.37°±2.42°（ -7.06°-12.12°）；②VCA均值为6.51°±1.34°（2.47°-11.91°）；③它们二者相关系数为0.72,为显著正相关；而颈干角，偏心距和股骨长度与股骨VCA的相关系数分别为-0.26，0.45和-0.08，均为低相关关系； ④通过理论截骨后股骨机械力线理想率A区间为5度截骨89.66%，6度截骨66.52%；B区间为5度截骨93.73%，6度截骨95.69%；C区间为5度截骨71.88%，6度截骨94.58%；而D区间为5度截骨21.19%，6度截骨50.80%。⑤在FBA的A区间的术后力线理想率第一组76.92%，第二组56.56%，第三组85.71%，第三组与其他两组间的差异有统计学意义； B区间的术后力线理想率第一组91.90%，第二组93.75%，第三组92.64%，组间差异无明显统计学意义；C区间的术后力线理想率第一组86.49%，第二组92.02%，第三组96.64%，第三组与第一组间的差异有统计学意义，与第二组间差异无统计学意义。D区间的力线理想率第一组33.64%，第二组61.29%，第三组84.72%，第三组与其余两组间差异均有统计学意义。

【结论】 TKA术前患者中FBA变化范围较大，由于其与VCA的显著正相关性， FBA远离均值的病例应特别注意VCA值的异常，常规的股骨5°或6°外翻截骨有时难以获得理想的下肢力线，需要根据实际的VCA值进行适度调整才能提高TKA术后力线理想率。

Part I  Analyse the different revolving postures’ influence on the measurement of femoral coronal bowing’s and femoral vulgas correction angle by CT three-dimensional reestablished model.

Object：The aim of this study was to evaluate the influence of rotary posture on the metrical resultes of the femoral bowing angle（FBA） and the femoral vulgas correction angle （VCA）through the lower limbs skeleton model which reestablished from the CT scaned data.
Methods:Choose the qualified cases from the vascular surgical patients of our hospital who had been examined by lower limbs angiography Computed Tomography.Rebuilt the lower limbs bones’model by mimmcs 16.0 software.Separate the cases into four groups by their femoral bowing angle(FBA) in the standard a-p position,such as group A (FBA>2),group B (2>FBA>0),group C(0>FBA>-2)and group D（FBA<-2）.There are 5 cases in every groups.Then make every model revolved through the vertical axis from 20 degree internal rotation to 20 degree external rotation by 2 degree for one motion and then get 21 photography for every case.Measured every photography’s FBA and femoral vulgas correction angle(VCA).

Results and Conclusion:① The measured FBA values of the 4 groups cases were 2.49°±0.46°(group A)，1.06°±0.39°(group B)，-1.41°±0.49°(group C)，-3.49°±0.74°(group D) .② The limb’s external rotation increase the FBA, the limb’s internal rotation decrease the FBA and the bigger FBA’s value in standard a-p position,the sharper variation of measured FBA value.The regression coefficient of each group is 0.47°/°（groupA），0.34°/°（groupB），0.33°/°（groupC）and 0.35°/°(groupD). ③The regression coefficient  between  the measured  VCA  value  and limb’s rotation in the 4 groups respectively are0.1°/°（groupA），0.03°/°（groupB），0.04°/°（groupC）and 0.07°/°(groupD).④The correlation index of the FBA and VCA in the different positions are 0.86 (GroupA)， 0.80 (GroupB)， 0.88 (GroupC) and 0.85 (GroupD).⑤The FBA value can be altered with the limbs’ rotation and even produce influence on the measurement of the whole limb’s alignment. And the bigger  FBA’s degree ,the more influence on the alignment.So when make the full length X-ray of lower limbs,making a standard posture for the legs is the key point,especially when a femur with a hyper- femoral bowing.   

Part II The individual difference of coronal bowing of femur and its influence on the lower limbs alignment and the total knee arthroplasty.

Object: Measure the femur bowing angle(FBA)， vulgas correction angle(VCA) and other parameters from the whole leg X-ray of the patienes who had sought for the total knee arthroplasty（TKA） treatment in our department and then analysye the data.Try to disclose the correlation between the FBA and VCA,anlysys its influence on the total knee arthroplasty and the lower limbs alignment.

  Methods: Collected the eligible cases who had seek for TKA in the department of Joint Surgery,China-Japan Friendship from Janurary in 2013 to December in 2015.Measure the FBA，VCA，offset of the proximal femur，the lengh of the femur,the neck shaft angle and the lateral distal femural angle（LDFA）of the femur of the eligible cases from the long leg X-ray.All the data were analysed for the following steps：①The FBA’s mean value and characteristics of distributation of all the cases. ②The VCA’s mean value and characteristics of distributation of all the cases. ③Correlations between the VCA and the other parameters; ④Divide all the cases into four regions base on the value of FBA : region A（FBA<-3°），region B（-3°≤FBA≤0°），region C（0°3°）and then imitate cuting the distal femur with 5° and 6°,respectively. Compare the percent of ideal alignmental outcome of every region. ⑤Divide all the cases into three groups base on the valgus osteotomy method:The first group which osteotomy by the 5 degree-valgus, the second group which osteotomy by the 6 degree-valgus and the third group which valgus osteotomy based on the actual VCA. Compare the percent of ideal alignmental outcome’s of every group on each FBA’s region after the TKA.

Results: ①The mean Value of the FBA is 1.37°±2.42°（ -7.06°-12.12°）, ②The mean Value of the VCA is 6.51°±1.34°（2.47°-11.91°）；③The correlation index between VCA and FBA, the neck shaft angle of the femur ,offset of the hip joint，the lengh of the femur is 0.72, -0.26，0.45 and -0.08,perspectively. ④The theoretical ideal alignment percentage Of the  5 degree-valgus-bone cut and 6 degree-valgus-bone cut in every group is  region A: 89.66% and66.52%；region B: 93.73% and 95.69%；region C: 71.88% and 94.58%；region D: 21.19% and 50.80%,respectively. ⑤The’s percent of ideal alignmental outcomes in region A are 76.92%（the first group），56.56%（the second group），85.71%（the third group）,respectively. In region B the results are 91.90%（the first group），93.75%（the second group），92.64%（the third group）,respectively. In region C the results are 86.49%（the first group），92.02%（the second group），96.64%（the third group） and the results are 33.64%（the first group），61.29%（the second group），84.72%（the third group）in region D.

Conclusion: The cases whose femur bowing angles are outliers are common in daily medical practice,so the vulgas correction angles need be ajusted for its significant correlation with FBA. 5 degree-valgus-bone cut or 6 degree-valgus-bone cut could not get the ideal alignment always.