Exploration Of The Correlation Between The Anatomical Morphology Of The Vastus Medialis Obliquus Injury And Patellar Instability In Adolescents-Measurement

Objective: To explore the correlation between VMO injury and adolescent patients with patellar instability by comparing the differences in anatomical morphological parameters of VMO-related injuries assessed by magnetic resonance imaging(MRI)between adolescent patients with patellar instability or lateral patellar dislocation(LPD)and healthy controls of the same age group,and to analyze and predict potential risk factors,so as to provide reference for clinicians to evaluate individualized treatment plans.Methods: The subjects of this study were selected from the adolescent population who underwent knee MRI in the Third Hospital of Hebei Medical University from January 2021 to October 2022.The keywords of " patellar instability," " patellar dislocation " and " patellofemoral malalignment " were input into the PACS reading system of our hospital as keywords.A total of 63 patients were included,and 65 healthy control participants of the same age group with no obvious abnormalities in the knee joint diagnosed by MRI were collected.Sagittal,coronal and axial MRI images were obtained in both groups.The measurement parameters were as follows : 1)the elevation height of VMO in sagittal plane and coronal plane;2)The cross-sectional area of VMO on the transverse axis of MRI and the average ratio to the cross-sectional area of the thigh;3)patellar tilt angle;4)Lateral patellofemoral angle;5)Lateral displacement of patella.SPSS 26.0 statistical software was used for data analysis.If the measurement data met the normal distribution,all parameters were expressed as mean ± standard deviation.Independent sample t test and chi-square test were used to compare continuous variables and categorical variables between the two groups.If the measurement data does not meet the normal distribution,the non-parametric test is used,expressed as M(P25-P75),and the Mann-Whitney rank sum test is used for comparison between groups.P < 0.05 is considered to be different,indicating that the results are statistically significant.At the same time,the Pearson correlation coefficient was calculated to determine the VMO-related injury anatomical parameters that were significantly positively correlated with patellar instability in adolescents.Results: In this study,compared with the control group,the elevation of VMO in the sagittal and coronal planes of the case group was significantly higher than that of the control group,specifically : 7.18(5.35,9.53)mm VS3.8(2.82,5.31)mm and 24.6(20.4,29.2)mm VS 6.48(4.99,7.74)mm,P <0.05,the difference was statistically significant.The average cross-sectional area ratio of VMO to thigh was 5 % in the case group and 6 % in the control group.The case group had mild VMO atrophy,P < 0.05,the difference was statistically significant.In addition,there was a significant positive correlation between ’ VMO coronal elevation mm ’ and ’ patellar tilt angle and patellar displacement ’ in adolescents with patellar instability.Conclusions: In this study,compared with control participants,there were obvious abnormalities in VMO anatomical morphological parameters in adolescent patellar instability or LPD patients,and there was a correlation.These findings are conducive to the timely assessment of potential VMO injury or VMO muscle atrophy in patients with patellar instability by MRI,so as to better develop individualized treatment plans for patients.