Study On The Correlation Between The Pathogenesis Of Accessory Navicular Bone And Flatfoot Of Ankle And Foot Based On Weight-Bearing X-Ray

Objective:To observe the correlation among the talus-accessory navicular angle(TANA),the calcaneal pitch angle(Pitch),the talus-first metatarsal angle(TMA)and the lateral talus-first metatarsal angle(Meary’s),to more intuitively judge whether there is a correlation between the accessory navicular bone(AN)and the flatfoot,to provide evidence of the correlation between the AN and the flatfoot from the perspective of imaging,and to deeply discuss its pathogenesis and biomechanical characteristics,At the same time,it provides a new theoretical basis and new ideas for the clinical operation and the related research of the AN.Methods:This study was a prospective cohort study.144 patients who met the inclusion criteria were divided into three groups according to the type of AN,44 cases in the type I AN group,46 cases in the type II AN group,54 cases in the type III AN group.The sex,age and left/right feet of each group were recorded,and the TANA,the pitch,the TMA and the Meary’s were measured in each group.Baseline data analysis was carried out for age and left/right feet,and univariate linear regression analysis was carried out in each group to observe whether there was correlation between the TANA and the pitch angle,the TANA and the TMA,the TANA and the Meary’s.The parameters between the three groups were analyzed by variance to observe whether there were differences in the parameters of each group in different a AN groups.Results:1.Three types of AN were found in sex(female/male ratio: 27/17 vs 25/21 vs 38/16,χ2=2.756,P=0.252),age(46.114 ± 16.246 vs 46.783 ± 15.364 vs 46.648 ± 16.247,F=0.022,P=0.978),left/right feet(left/right foot ratio: 23/21 vs 19/27 vs 29/25,χ 2=1.751,P=0.420),the difference was not statistically significant.Gender,age,left/right feet had no effect on the type of AN and flat foot.2.In the univariate linear regression analysis,there is correlation between the TANA and the pitch,the TANA and the TMA,and the TANA and the Meary’s in the three types of AN.The univariate linear regression equation is established respectively as type I AN group(Y=23.384+2.206 X,Y=26.603+3.231 X,Y=42.498+1.626X),Type II AN group(Y=37.381+1.413 X,Y=48.136+1.143 X,Y=46.252+1.485X),type III AN group(Y=28.004+1.795 X,Y=30.054+2.542 X,Y=39.061+1.874X),the TANA in each group was positively correlated with the angle of each group.3.Three types of TANA(55.318 ± 9.885 vs 59.065 ± 8.572 vs 54.296 ± 9.826,F value=3.698,P value=0.029),the pitch(14.477 ± 2.338 vs 15.348 ± 2.406 vs 14.648 ± 2.679,F value=1.576,P value=0.210),the TMA(8.886 ± 1.280 vs 9.565 ± 1.974 vs 9.537 ± 1.756,F value=2.322,P value=0.102)The Meary’s(7.886 ± 2.315 vs 8.630 ± 2.069 vs 8.129 ±2.266,F value=1.327,P value=0.269)showed statistically significant differences in the TANA.The size of the TANA in different types of AN is different.The TANA can be used as the basis for distinguishing the types of the AN.Conclusion:(1)The TANA is a quantitative indicator of the change of AN position,which is representative of the subtle change of AN;(2)According to the correlation between the TANA and Meary’s,TMA and Pitch,it can be inferred that AN is related to flatfoot;(3)In type II AN and type III AN,the value of the TANA can be used as one of the indicators to determine flatfoot;(4)The measured critical the value of the TANA is 61.5,which can be determined as AN causing flatfoot when the TANA is greater than 61.5.