The value of anterior femoral tilt in assessing hip impingement syndrome by MRI

ZHAO Ji-xiang; LIU Guang-wang; ZHU Zi-he

doi:10.3969/j.issn.2095-252X.2025.08.012

Abstract：Objective To investigate the value of MRI to measure the femoral anteversion angle(FAA)for femoral-acetabular impingement(FAI)syndrome.Methods A total of 55 patients with FAI admitted to the Department of Orthopedics from January 2022 to February 2024 with an average age of(42.67±8.47)years were selected,and 48 patients in the normal control group(asymptomatic FAI)with an average age of(41.49±9.18)years were selected.Twelve items of general data and 10 items of immunoinflammatory factors were collected and statistically analyzed.The differences in age,gender and location of FAA among the control group,the FAI group and the three subtypes were compared.The FAA was divided into quintile groups(F1-F5)according to the FAA level from low to high,and the correlation subgroup analysis between FAA and FAI was conducted.The restriction cubic spline method combining spline function and logistic regression was used to analyze the dose-response relationship between FAA and FAI.Results Comparing general data and immunoinflammatory factors between the control group(n=48)and the FAI group(n=55),it was found that there were statistically significant differences in gender(male/female:29/19 vs.22/33),age(<45 years old/≥45 years old:19/29 vs.35/20),ischiofemorai impingement(IFI)(18/37.50%vs.22/40.00%),femoral neck bone marrow edema(5/10.42%vs.17/30.91%),subtype(clamp type/cam type/hybrid type:21/18/9 vs.9/31/15),and peritrochanteric muscle edema(13/27.08%vs.35/63.64%)between the two groups(P<0.05).The levels of immunoglobulin A(IgA)[(1.63±0.37)g/L vs.(1.85±0.45)g/L]and hypersensitive C-reaction protein(hs-CRP)[(9.65±0.98)mg/L vs.(10.68±1.64)mg/L]in the control group were significantly lower than those in the FAI group(P<0.05);The FAA of women in the control group[(23.64±5.19)° vs.(20.34±5.18)°]and FAI group[(24.82±6.89)° vs.(18.52±6.43)°]was significantly higher than that of men(P<0.05);There was no statistically significant difference in age and location between the two groups(P>0.05).The FAA of cam type was significantly lower than that of the other two FAI subtypes[(18.39±6.31)°,(22.56±7.59)°,(27.63±6.38)°](P<0.05),and the FAA of cam type was significantly higher in women than in men[(22.79±5.23)° vs.(18.45±5.19)°](P<0.05).Subgroup analysis of the correlation between FAA and FAI showed that FAA and FAI were more significant in female FAI patients(OR=1.63,95%CI=0.88-2.26)and male FAI patients(OR=2.66,95%CI=2.08-3.24)(Pinteraction<0.05).The results of restriction cubic spline analysis showed that the continuous change of FAA and the intensity of FAI association showed a nonlinear dose-response relationship regardless of the early,developmental and severe stages of FAI(nonlinear detection,P<0.001).Conclusions With the continuous increase of FAA,the intensity of its association with FAI increases nonlinearly,and the risk of FAI increases significantly when the FAA>20°.The correlation between FAA and FAI is more obvious in female FAI patients and male FAI patients.