Magnetic Resonance Imaging(MRI)-Based Risk Factors Investigation Of Patellar Instability

Objective: This study is to analyze the rates and correlations among multiple tissue injuries and related anatomical measurements in patellar instability based on magnetic resonance imaging(MRI).Methods:Totally 131 patients with patellar instability were included and subjected to the MRI detection.Anatomical patellar instability measurements and MRI indices were recorded.Differences and correlations were analyzed among the measurements and tissue injuries.Results:Significant differences existed in these four measurements between the patient and control groups: the sulcus angle,trochlear groove depth,facet ratio,and Insall-Salvati ratio.Moreover,trochlear dysplasia was existed in 90.84% of patients and patella alta occurred in 58.78% of patients.There were multiple tissue injuries in the patient group,including the lateral retinaculum,medial retinaculum,anterior cruciate ligament,medial collateral ligament,patella,femur,medial meniscus,and lateral meniscus,rather than in the control group.In the patient group,there were significant positive correlations between the age and the multiple tissue injuries,with relatively lower correlations in the control group.Furthermore,the onset age of patellar instability was significantly negatively correlated with the trochlear angle and Insall-Salvati index.Conclusion:More severe trochlear dysplasia and patella alta are often accompanied by younger onset age of patellar instability.Likewise,tissue injuries show stronger correlation with older age in the patients.Correcting patellar instability at early stage might be effective to prevent secondary injuries and related sequelae.