MRI横断面定量测定指标对髌骨关节不稳的诊断价值

目的：探讨MRI横断面定量测定指标对髌骨关节不稳的诊断价值。方法回顾性分析髌骨关节不稳患者32例（髌骨关节不稳组）和正常人42例（对照组）的MRI影像学资料。两组均采取仰卧位及双膝完全伸直进行MRI检查，扫描范围均为右侧全膝关节。 MRI图像的测量指标包括股骨滑车面对称性、股骨滑车深度、股骨外侧滑车倾斜度、髌骨倾斜角、髌骨外移度、股骨滑车与胫骨结节间的水平距离（ TTTG）。结果两组股骨滑车面对称性、股骨滑车深度、股骨外侧滑车倾斜度、髌骨倾斜角、髌骨外移度结果比较，差异有统计学意义（P＜0．05），但是两组TTTG结果比较，差异无统计学意义（P＞0．05）。股骨滑车面对称性、股骨滑车深度、股骨外侧滑车倾斜度、髌骨倾斜角、髌骨外移度和TTTG的ROC曲线下面积分别为0．954、0．955、0．943、0．922、0．971、0．521；股骨滑车面对称性、股骨滑车深度、股骨外侧滑车倾斜度、髌骨倾斜角、髌骨外移度诊断界值分别为54％、15°、5 mm、16°、3 mm，敏感度为91．3％、85．2％、91．5％、83．1％、79．1％，特异度分别为91．4％、97．5％、88．4％、90．1％、100％。结论在行膝关节伸直位MRI检查时，股骨滑车面对称性、股骨滑车深度、股骨外侧滑车倾斜度、髌骨倾斜角、髌骨外移度对髌骨关节不稳的诊断价值较高。

Value of quantitative measurement of transect MRI indices in diagnosis of patellar instability

Objective To explore the value of quantitative measurement of transect MRI indices in the diagnosis of patellar instability . Methods MRI imaging data of 32 patients with patellar instability (patellar instability group) and 42 healthy individuals(control group) were retrospectively analyzed .Both groups received MRI examination with supine position and double knee extension .The scan range was total right knee joint .The detection indices of MRI images included symmetry of femoral trochlear surface ,femoral trochlear depth ,tilt angle of lateral femoral trochlea,patellar tilt angle,lateral shift of patella,tibial tuberosity-trochlear groove distance (TTTG).Results There were significant differences in the symmetry of femoral trochlear surface ,femoral trochlear depth ,tilt angle of lateral femoral trochlea ,patellar tilt angle and lateral shift of patella between two groups (P<0.05).But no significant difference in TTTG was found between two groups (P>0.05).The areas under receiver operating characteristic (ROC) curve of the symmetry of femoral trochlear surface ,femoral trochlear depth,tilt angle of lateral femoral trochlea ,patellar tilt angle,lateral shift of patella and TTTG were 0.954,0.955,0.943,0.922,0.971 and 0.521,respectively.For the symmetry of femoral trochlear surface ,femoral trochlear depth ,tilt angle of lateral femoral trochlea ,patellar tilt angle and lateral shift of patella,the diagnostic threshold values were 54%,15°,5 mm,16°and 3 mm,respectively,the sensitivities were 91.3%,85.2%,91.5%,83.1%and 79.1%,respectively,and the specificities were 91.4%,97.5%,88.4%,90.1% and 100.0%, respectively .Conclusion In MRI examination with knee extension ,the symmetry of femoral trochlear surface ,femoral trochlear depth ,tilt an-gle of lateral femoral trochlea ,patellar tilt angle,and lateral shift of patella are valuable for the diagnosis of patella instability .