CT-based Morphological Study Of The Pelvis In Patients With Gluteal Muscle Contracture

Objective: Gluteal muscle contracture(GMC)is a clinical syndrome characterized by fibrous contracture of the gluteal muscles and related fascia.This study aimed to measure the pelvic morphological parameters between GMC patients and normal people by CT,and summarize and analyze their imaging characteristics,so as to provide a reference for clinical diagnosis and treatment.Methods: This is a retrospective study.100 GMC patients who were admitted to our hospital from January 2019 to January 2020 and met the inclusion and exclusion criteria were selected as the GMC group.During the same period,and 100 patients who came to our hospital for emergency treatment due to trauma without pelvic and hip joint diseases were selected as the control group.All subjects underwent CT scans to measure their pelvic rotation,including the superior iliac angle(SIA),inferior iliac angle(IIA),and ischiopubic angle(IPA).Acetabular coverage: anterior acetabular sector angle(AASA),posterior acetabular sector angle(PASA),horizontal acetabular sector angle(HASA),and superior acetabular sector angle(SASA).And ischial femur impact evaluation index:ischiofemoral space(IFS).Independent sample t test was used to compare and analyze the differences between the GMC group and the control group.Meanwhile,the correlation between various parameters in the GMC group was analyzed.The diagnostic value of pelvic rotation angle and acetabular covering angle was evaluated by ROC curve.Results: 1.The parameters were compared between GMC group and control group: The SIA,IIA,IPA,and PASA of the GMC group were considerably smaller than those of the control group,while the AASA of the GMC group was higher,indicating a statistically significant difference(P < 0.05).The HASA and SASA of the GMC group,on the other hand,were not considerably different from those of the control group.2.In the GMC group,the correlations of pelvic parameters were as follows: The HASA had a positive correlation with the AASA and PASA(r=0.750,P<0.01;r=0.749,P<0.01);the SASA had a positive correlation with the AASA,PASA,and HASA(r=0.555,P<0.01;r=0.273,P<0.01;r=0.552,P <0.01);the AASA had a negative correlation with the SIA,IIA and IPA(r=-0.355,P<0.01;r=-0.551,P<0.01;r=-0.30,P<0.01);the PASA had a positive correlation with the IIA(r= 0.315,P<0.01)and had no correlation with the SIA and IPA(P>0.05);the IIA had a positive correlation with both the SIA and IPA(r=0.664,P < 0.01;r=0.465,P < 0.01),the SIA had a positive correlation with IPA(r=0.217,P < 0.05);the IFS had a negative correlation with IPA(r=-0.203,P < 0.05).3.ROC curve analysis showed that the sensitivity and specificity of AASA,PASA,SIA,IIA,IPA for the diagnosis of gluteal muscle contracture were(73%,68%),(68%,61%),(90%,58%),(91%,59%),(89%,58%),respectively.The area under the curve was 0.73,0.67,0.79,0.81,0.79,respectively.There were significant differences in the above indicators between two groups(P < 0.05).Conclusions: 1.Individuals with GMC have an abnormal pelvic morphology,with acetabular retroversion caused by pelvis rotation rather than dysplasia of the acetabular wall.2.The angle of pelvic rotation has a certain reference value for the screening of patients with GMC.3.The distance between the ischial femur spaces in patients with GMC was significantly larger than that in normal people,suggesting that the ischial femur impinging syndrome is not easy to occur in patients with GMC.