改良后足力线X线测量方法研究及其对平足患者的评估价值

Modified hindfoot alignment radiological evaluation and application in the flatfoot

目的探讨一种新的基于X线片的后足力线拍摄和测量方法,及其对平足患者的评估准确性。方法前瞻性对照研究。纳入西安交通大学附属红会医院足踝外科自2018年1—12月收治的28例(40足)平足患者(平足组),20名(40足)健康志愿者(对照组),采用自主设计的Saltzman位拍摄架,分别进行10°、15°、20°、25°、30°后足力线位X线拍摄。比较两组年龄、性别、侧别、体质量指数(BMI)的差异。比较对照组标准Saltzman位(20°位)X线片改良胫骨后足角(THA)测量法与van Dijk法和改良van Dijk法测量后足力线角度的结果;比较三种测量方法对照组THA的测量结果与文献报道的负重CT下测量THA结果的差异。观察所有影像学资料在五种投射角度下胫距关节的可见率,并评估改良THA测量方法在不同投照角度的差异。通过改良THA法,测量平足患者的后足外翻角度。结果平足组患者与对照组年龄、性别、侧别、BMI差异均无统计学意义(P值均>0.05)。三种测量方法的组内一致性均为优,改良THA测量法一致性最佳(组内相关系数为0.928);对照组中改良THA法测量的后足力线角度大于van Dijk法和改良van Dijk法,差异有统计学意义(F=0.092,P<0.01);改良THA测量结果与负重CT测量结果差异无统计学意义(P>0.05)。胫距关节可见率:对照组10°、15°、20°投射均可见(100%,40/40),25°投射部分可见(70%,28/40),30°位均不可见(0%,0/40);平足组10°投射均可见(100%,40/40),15°、20°投射部分可见(分别为80%、32/40,45%、18/40),25°和30°均不可见(0%,0/40)。对照组的改良THA法测量值在10°、15°、20°投射分别为4.84°±1.81°、4.96°±1.77°、4.94°±2.04°,差异无统计学意义(F=1.570,P>0.05);平足组在10°、15°、20°投射均可见18足,其改良THA法测量值分别为13.58°±3.57°、13.62°±3.83°、13.38°±4.06°,差异无统计学意义(F=0.197,P>0.05)。结论改良THA测量方法操作简单,存在较高的组内一致性,可以用于后足力线评估。对于平足患者,基于10°位X线拍摄,采用改良THA法测量后足力线角度,可以准确地反映后足外翻程度。

Objective To explore a new method of radiological and measuring the posterior foot line of force based on X-ray films,and to study the evaluation accuracy of flatfoot patients.Methods Prospective study.Twenty-eight patients(40 feet)with flatfeet(flatfoot group)and 20 volunteers(40 feet,control group)admitted to foot and ankle surgery department of Honghui Hospital of Xi'an Jiaotong University,were taken from January to December 2018.The Saltzman position shooting stand independently designed by our department has been used to take the hindfoot alignment X-ray at 10°,15°,20°,25°,30°respectively.The differences in age,gender,gender,and BMI were compared between the two groups.The modified tibio-hindfoot angle(THA)at standard Saltzman position(shooting at 20°)and the consistency with the van Dijk method and the modified van Dijk method were evaluated.The THA results of the three measurement methods with the weighted CT measurements reported in the literature were compared.The visibility of tibiotalar joint space of all imaging data at five projection angles were observed;and the consistency of the modified THA method at different projection angles were evaluated.Results There was no significant difference in age,gender,sides,or BMI between the two groups(all P values>0.05).The intra-group consistency of the three measurement methods was excellent,and the intra-group consistency was the best in modified THA group(intraclass correlation coefficient was 0.928).The results of modified THA method were significantly larger than those of van Dijk method and modified van Dijk method.The mean THA in standard Saltzman view in normal people were significantly different between the three evaluation methods(F=0.092,P<0.01).There was no significant different between the results of modified THA method and the weight-bearing CT(P>0.05).The tibiotalar space in the normal group were visible in all cases at 10°,15°,20°(100%);and visible in some cases at 25°(70%);and invisible in all cases at 30°(0%).In the flatfoot group,the tibiotalar space were visible in all cases at 10°(100%);and in some cases at 15°and 20°(80%);and invisible in all cases at 25°and 30°(0%).In the normal group,the modified THA was 4.84±1.81°at 10°,4.96±1.77°at 15°,4.94±2.04°at 20°.No significant difference was found between the three groups(F=1.570,P>0.05).In the flatfoot group,the modified THA of 18 feet,which was visible at 10°,15°and 20°,was 13.58°±3.57°at 10°,13.62°±3.83°at 15°and 13.38°±4.06°at 20°.There was no significant difference between the three groups(F=0.197,P>0.05).Conclusions The modified THA evaluation method is easy to operate and has high inter-group and intra-group consistency.It can be used to evaluate hindfoot alignment.For patients with flatfeet,the 10°position view and modified THA measurement can be used to evaluate the hindfoot valgus conditions.