Study On Correlation And Difference Of Each Measurement Angle Of X-Ray Film Under Weight-Bearing Position Of Children’s Flatfoot

Objective: To investigate the feasibility of using calcaneal pitch angle,lateral longitudinal arch angle,medial longitudinal arch angle and second metatarsal angle of the talus as indicators to assess the severity of flatfoot in children.Methods: The medical records of 193 cases(351 feet)with flatfoot diagnosed by orthopedists as aged ≥3 years old in the outpatient department of our hospital from August 2019 to April 2020 were analyzed retrospectively.SMAOT on the positive weight-bearing radiograph and Meary’s angle(MA),LLA,MLAA and CPA;on the lateral weight-bearing radiograph were measured,respectively.The maximum static plantar pressure and its location were measured,and the correlation and difference analysis between the measured data and age,gender,and BMI were conducted.Then 193 cases were divided into three groups with MA as the diagnostic standard,mild flatfoot,moderate flatfoot and severe flatfoot.The correlations and differences of CPA,LLA,MLAA and SMAOT in the three groups were analyzed.Results: Calcaneal pitch angle has the highest accuracy was 78.3%;The average values of measured angles in different degrees of flatfoot:calcaneal pitch angle: mild flatfoot(16.77±4.69),moderate flatfoot(15.15±4.62),severe flatfoot(13.50±5.08),the difference was statistically significant(F = 4.684,P = 0.010 < 0.05);Lateral longitudinal arch angles of mild(144.91±6.38),moderate(148.04±6.11)and severe(157.05±8.36)flatfoot showed statistical significance(F=17.262,P=0.000<0.05);Medial longitudinal arch angles of mild flatfoot(130.43±7.73),moderate flatfoot(136.59±8.03)and severe flatfoot(140.83±17.76),the differences were statistically significant(F=21.381,P=0.000<0.05);Second metatarsal angle of talus: mild flatfoot(15.10±7.76),moderate flatfoot(16.82±7.81)and severe flatfoot(17.20±9.72),the differences were not statistically significant(F=1.601,P = 0.203 > 0.05).Meary’s angle had a negative correlation with the calcaneal pitch angle(r =-0.170,P < 0.05),Meary’s angle had a positive correlation with the lateral longitudinal arch angle(r=0.368,P < 0.05),Meary’s angle had a positive correlation with the medial longitudinal arch angle(r=0.424,P < 0.05),and Meary’s angle had a positive correlation with the second metatarsal angle of the talus(r=0.101,P > 0.05).Conclusion: The calcaneal pitch angle,the lateral longitudinal arch angle,and the medial longitudinal arch angle which are more intuitive to display and have a simpler measurement method can be used as indicators for judging the severity of the flatfoot in children,and the evaluation criteria for the calcaneal inclination angle does not change with age.As the medial and lateral longitudinal arch angles grow older,there should be different evaluation criteria,while the second metatarsal angle of the talus cannot be used as an indicator for evaluating the severity of the flatfoot in children,and further measurement data of more children with flatfoot of different ages and normal children need to be included in the follow-up to further divide the criteria.