A Comparative Study Of Acetabular Dome Method And Femoral Head Method In The Measurement Of Pelvic Parameters Of Patients With Adult Degenerative Scoliosis

Objective The aim of this study is to compare the results of the sagittal parameters of pelvis of the patients with adult degenerative scoliosis measured by acetabular dome method and femoral head method respectively,and to contrast and analyze the results of pelvic sagittal parameters measured by beginners using two methods.And then to confirm that whether the results of the parameters measured by two methods are consistent,and whether there are some differences between the two methods used by beginners.Methods 1.The clinical and imageology data of patients treated in the department of orthopedics in our hospital from October 2016 to October 2019 were reviewed.According to the exclusion criteria,60 standing lateral radiographs of spine of the patients were selected.All of the radiographs were imported into the Surgimap 2.3.1.1 and S1 endplates of all images had been marked and saved in the database.PI parameter system was selected as the measurement object of the study,and the parameters of PI and PT were measured by two methods respectively in the Surgimap.Two series of measurements were performed between 1 week and the average value of three times measurements was recorded as each result of every image.The differences of the results were tested by matched samples t-test,and agreements between PI and PT measured by two methods and agreements between two series in each method were quantified by the intraclass correlation coefficient(ICC).2.20 surgical students in our hospital were selected as the beginners.One of the 60 standing lateral spine radiographs selected was picked out randomly as the test sample,and five of the 59 remaining radiographs were picked out randomly as the teaching and exercise materials.The standard value of each radiograph picked out was the average value of the results measured by two methods in the first part of the study,and the marks of S1 endplates were remained.All beginners were taught in a group and the operations of the Surgimap were demonstrated at the same time.Beginners were deemed to have passed the exercise when he or she completed the measurements of pelvic parameter independently more than3 images.And then,2 series measurement of pelvic parameters of PI and PT were performed by all beginners at the same times between 1 week interval and the average value of three times measurements was recorded as the result of every beginner.The qualification rates of PI and PT measured by two methods were compared and analyzed,and agreements of measurements between two series in each method were quantified by the intraclass correlation coefficient(ICC).Results 1.There was no statistically significant differences between the results of the two methods(p>0.05),and there was no statistically significant differences between the two series measurement in each method(p>0.05).The results of PI measurement have excellent reliability between two method,the ICC were 0.988(first series,p<0.000)and0.986(second series,p<0.000);as for PT,the ICC were 0.997(first series,p<0.000)and0.996(second series,p<0.000).The results of PI measurement between two series in each method has excellent repeatability,the ICC were 0.991(acetabular dome method,p<0.000)and 0.987(femoral head method,p<0.000);as for PT,the ICC were 0.997(acetabular dome method,p<0.000)and 0.996(femoral head method,p<0.000).2.The qualification rates of PI measurement of beginners were 90%(by acetabular dome method)and 55%(by femoral head method),the difference between two methods has statistical significance(p =0.016<0.05);as for PT,the qualification rates were 90%(by acetabular dome method)and 60%(by femoral head method),there was statistical significant difference(p =0.031<0.05).The results of PI measured by beginners between two series in each method were different,the ICC were 0.816(acetabular dome method,p<0.000)and 0.682(femoral head method,p<0.000);as for PT,the ICC were 0.825(acetabular dome method,p<0.000)and 0.733(femoral head method,p<0.000).Conclusion In the measurements of PI and PT of the patients with adult degenerative scoliosis,the acetabular dome method and femoral head method have excellent agreement and repeatability.The two methods can be used alternatively depended on the quality of radiographs.Beginners who have less experience can choose the acetabular dome method to measure PI and PT of the patients with adult degenerative scoliosis,which can get sagittal pelvic parameters with higher qualification rates than the femoral head method.The acetabular dome method is more suitable for beginners to learn and operate.