A Study About Children's Developmental Dislocation Of Femoral Neck Anteversion Variatable Law In Three-dimensional CT

ObjectiveTo observe the relationship between FNA and age in patients with the developmental dislocation of the hip,using three-dimensional CT method, observe the difference between the two measurement methods to FNA, two-dimensional and three-dimensional CT.MethodsUsing three-dimensional reconstruction,to measure femoral neck anteversion of 237 patients (456 hips) with developmental dislocation of the hip, by two-dimensional measurement method and three-dimensional CT reconstruction methods, then the results were compared to three-dimensional CT measurements as a standard reference. Age range 5-10.5 years. Dividing each year for one group, all patients did not get any treatment before hospitalized, including 81 cases with bilateral hip dislocation,156 cases with unilateral hip dislocation, in total 309 cases hips with dislocation,while 156 cases without dislocation.34 cases withⅠdegree of dislocated hips,132 cases withⅡdegrees dislocation,89 cases withⅢdegrees dislocation,54 cases with IV degrees dislocation,cases without hip dislocation as control group were analyzed statistically.ResultsFor DDH patients, FNA in the hip side without dislocation increased with age, from 33.87°in one year old gradually to 49.50°in 6 years old, and then gradually decreased to 33.33°in 9 years old. FNA in hip lateral without dislocation and age are correlated (Pearson correlation coefficientγ=0.013, P<0.05); FNA in hip lateral with dislocation increased with age, from 33.13°in one year old to 46.8°in ten years old, from 1 to 4 years old, FNA increased significantly, reaching to 42.19°, and then no more increasing, maintained at 41°, until the age 10 years old,reaching to 46.8°, FNA in hip lateral without dislocation and age are correlated (Pearson correlation coefficientγ=0.244, P<0.0001). FNA in both laterals with or Without dislocation of the hip increased with the degree of dislocation, from 35.81°without dislocation to 39.96°with IV defree dislocation, FNA in hip lateral with or without dislocation of the hip measured by three-dimensional CT and age were correlated (Pearson correlation coefficientγ=0.181, P<0.0001). There are two ways to measure FNA,two-dimensional CT and three-dimensional CT.Every cases'FNA was measured by two-dimensional and three-dimensional,and measurement of the two methods were compared then it is found significant differences between the two, that is FNA's mean by three-dimensional measurement get over 3.09°than two-dimensional measurement.ConclusionFNA in the hip lateral without dislocation increased with age, from 33.87°in one year old gradually to 49.50°in 6 years old, and then gradually decreased to 33.33°in 9 years old. FNA in hip lateral without dislocation and age are correlated statictially.FNA in hip lateral with dislocation significantly higher than hip lateral without dislocation, FNA and age, degree of dislocation were significantly correlated statistically,increasing with degree of dislocation and patient's age.FNA were measured by Two-dimensional CT and three-dimensional CT measurements outcome were compared,there is a significant difference between the two, FNA's mean by three-dimensional measurement get over 3.09°...