The Study Of Correlation Of Noncontact Anterior Cruciate Ligement Injury With Lateral Femoral Condyle Morphology

Purpose:The purpose of this study was to investigate the influence of the knee lateral compartment bony morphology and morphometry on risk of noncontact anterior cruciate ligament(ACL)injury.Methods:Patients who underwent arthroscopic knee surgery in our hospital from 2016 to 2018 with minimum follow-up of 12 months were retrospectively reviewed.A total of 80 age and sex-matched patients(40 ACL-ruptured and 40 ACL-intact)were included.Patients were stratified into 2 groups:(1)a control group of patients consisting of isolated meniscal tears(2)patients with primary ACL injury.ALL the lateral femoral bone morphology and morphometric parameters were measured on knee magnetic resonance imaging(MRI).the ratio of posterior femoral condylar depth to total condylar length was defined as the lateral femoral condyle ratio(LFCR).The lateral femoral condyle index(LFCI)as a novel MRI measurement was developed to quantify femoral sphericity.The distances of the flattened surface of the distal femoral condyle was divided by anteroposterior distance of the tibial plateaus.This ratio was defined as The Porto Ratio(TPR).In addition,notch width index(NWI),a previously known MRI risk factor associated with ACL injury were analyzed.Differences among groups were compared;cutoff values were defined with ROC curve;and diagnostic performance of the risk factors was assessed.Result:All of bone morphological parameters were different between ACL-ruptured and control group(P<0.05).ACL-ruptured subjects showed statistical significant smaller lateral femoral condyle index(LFCI,0.683±0.042),notch width index(NWI,0.243±0.018),and higher lateral femoral condyle ratio(LFCR,0.635±0.021),The Porto Ratio(TPR,0.879±0.043)than in the contral group(P<0.001).The LFCR yielded the highest area under the curve among the analyzed risk factors: 0.86(95% CI,0.76-0.94).A cutoff of 0.625 yielded a sensitivity of 67.5% and a specificity of 85.0% to predict an ACL rupture.Conclusion:The most important finding of this study was that the calculated ratios(LFCR;LFCI;TPR;NWI)showed a significant accuracy in identifying the individuals with and without an ACL injury.These findings may contribute to injury risk assessment,sports participation,and injury prevention counseling and surgical planning refining by identifying high-risk patients who would benefit from the addition of associated procedures to the anatomic ACL reconstruction aiming the improvement of knee stability and decrease the risk of further injuries.