The Evaluation And Application Value Of CT Quantitative Measurement Indexes For Hip Impingement Syndrome

Objective1.To investigate the anatomical parameters associated with femoroacetabular impingement(FAI)in a Chinese asymptomatic population by high-resolution reconstructed multislice CT images,and to evaluate the prevalence of the radiographic features of cam and pincer types in Chinese patients.2.To investigate the clinical significance of femoral anteversion in patients with different subtypes of FAI by comparing the angle measured on CT with normal control group.Materials and methods1.We reviewed the CT images of 470 hips in 235 Chinese patients who underwent abdominal and pelvic CT scans for reasons unrelated to hip symptoms at our hospital between February and October 2017.The following measurements relating to FAI were made on each hip joint: acetabular version(AV),anterior acetabular sector angle(AASA),posterior acetabular sector angle(PASA),the lateral centre edge angle(LCE),the alpha angle(AA),and femoral head-neck offset(FHNO).2.A total of 58 patients with surgically confirmed femoroacetabular impingement from May 2017 to September 2018 were enrolled.The femoral anteversion was measured and compared with the normal adult control group.Results1.Significant differences in all parameters were seen between men and women.The average of acetabular version in all three positions and the average of AASA in men were smaller than that of females,while the average of AASA,LCE,AA and FHNO in men was larger than that of women.In the age group,the average of acetabular version in young men at three positions was smaller than that of elderly men,while the average of acetabular version in three levels in elderly women was smaller than that of young women,so young men and elderly women showed more retroversion in our study.LCE,AA and FHNO were all larger in men than women.The data showed 25 % of female joints and 34.5 % of male joints had at least one predisposing factor for FAI using measurement parameters by CT images in Chinese asymptomatic patients,and the prevalence of pincer lesion was larger than cam lesion.2.In both the case group and the control group,women had a significantly larger anteversion than men(P<0.02),but there was no statistical difference in left hip and right hip.The mean values of femoral anteversion in different subtypes of FAI and normal controls was(18.90±6.17)°,(28.60±6.28)°,(22.88±8.83)° and(21.81±5.50)°.There was no significant difference in femoral anteversion between the mixed-type FAI group and the normal group,but there was statistical difference between the other two groups.Conclusion1.Chinese asymptomatic patients were also at risk of FAI.Men were more likely to develop FAI than women,and pincer deformities were more common than cam deformities.The threshold values for abnormal parameters should be reconsidered based on gender,age and other factors in order to improve the accuracy of diagnosis.2.CT scan is the main method for measuring femoral anteversion in patients with FAI before operation.There is a certain difference between the anteversion in different subtypes of FAI.Excessive or too small femoral anteversion plays an important role in the pathogenesis and treatment of FAI.