Study Of Anatomical Risk Factors For Non-contact ACL Injury

Objective:In order to provide risk assessment and early prevention of anterior cruciate ligament(ACL)injury in clinical practice,the anatomical parameters of the knee joint of patients with non-contact acl injury were measured by magnetic resonance imaging(MRI).Methods:In this study,41 patients with ACL injury diagnosed and treated in our hospital from 2017 to 2019 received MRI of knee joint as the experimental group,including 23 males and 18 females.The control group consisted of 62patients with normal ACL diagnosed by MRI,which was confirmed by professional orthopedic surgeons and radiologists.The anteroposterior diameter of the sagittal ACL and the anteroposterior diameter of the tibia,the posterior slope of the medial and lateral tibial plateau,the patellar tendon-tibial anatomical axis angle,the width of the intercondylar eminence of the tibial coronal position,the transverse diameter of the tibial plateau,the width of the intercondylar notch,the height of the intercondylar notch,the width of the femoral condyle,and the anteroposterior diameter of the axial intercondylar notch were measured on the MRI image.The index of the width of the intercondylar notch,the index of the shape of the intercondylar notch,the cross section area of the intercondylar notch,the index of the width of the tibial intercondylar eminence,the index of the ACL,and the deviation of the tibial plateau were calculated.The statistical difference of anatomical parameters of knee joint between the experimental group and the control group was analyzed.Results:Male patients with ACL injury had smaller acl-fossa diameter(15.26mm vs 17.53mm,P<0.001),acl-fossa index decreased(0.27 vs 0.31,P<0.001),patellar tendon-tibial anatomical axis angle(18.75°vs 25.9°,P<0.001),intercondylar notch width(NW)(17.96mm vs 19.65mm,P=0.01),and intercondylar notch width index(NWI)(0.23 vs 0.26).P=0.003),intercondylar notch depth(INH)(25.28mm vs 27.73mm,P<0.001),intercondylar fossa cross sectional area(CSA)level(480.30mm~2 vs 524.70mm~2,P=0.009),intercondylar fossa cross sectional area(CSA)coronal position(455.43mm~2 vs 545.19mm~2,P<0.001),among which PTTSA is an independent influencing factor.When PTTSA is less than 21.84°,the posibility of ACL injury is higher.Female patients with ACL injury had smaller intercondylar eminence width(EW)(12.05mm vs 13.97mm,P<0.001),patellar tendone-tibial anatomical axis angle(18.78°vs 25.70°,P<0.001),intercondylar notch depth(INH)(24.16mm vs 25.62mm,P=0.027),and intercondylar notch width(NW)(16.01mm vs 17.55mm).P=0.009),CSA level(438.6 mm~2 vs 483.45 mm~2,P=0.017),CSA coronal position(390.53mm~2 vs 449.71 mm~2,P=0.014),intercondylar eminence index(EWI)(0.17 vs0.21,P<0.001),and intercondylar fossa width index(NWI)(0.23mm vs0.25mm,P=0.009).When PTTSA<19.47°or EWI<less than 0.19,the possibility of ACL injury was higher,and the correlation between the two was greater than that between the index of intercondylar eminence.Conclusion:In the anatomical parameters of the knee measured by MRI,the smaller width of the intercondylar notch,the depth of the intercondylar notch,the volume of the intercondylar notch,and the patellar tendon-tibial anatomical axis angle were risk factors for ACL injury in males.Smaller intercondylar eminence width,intercondylar notch width,intercondylar notch depth,intercondylar notch volume,patellar tendon-tibial anatomical axis angle are risk factors for ACL injury in women.There are differences in the anatomical risk factors for non-contact ACL injuries between men and women,so patients with the above risk factors should be discussed separately according to gender,and preventive measures should be taken for the knee joints without ACL injuries.