动态MRI对髌股关节排列和运动轨迹的评价研究

The study of the patellofemoral malalignment and track with Dynamic MRI

目的探讨动态MRI技术对髌股关节排列关系及其运动规律的评价方法和价值,以便更准确判断髌股关节病变,为临床提供可靠的诊断依据。方法选取有髌股关节排列和运动轨迹异常的30例患者共43膝为试验组,另外选取无髌股关节症状和体征的志愿者15例共30膝为对照组,分别对2组膝关节进行动态MRI检查,在膝关节完全伸直位(屈膝0°)和屈膝6°、12°、18°、24°、30°、36°,连续成像,在各个角度下对髌骨倾斜角(PTA)、适合角(CA)、股骨滑车角(FTA)进行准确测量,比较2组患者各项测量值的差异性并寻找髌股关节的运动规律。结果 2组患者膝关节间PTA、FTA、CA值在膝关节不同屈曲角度差异均有统计学意义(P<0.05)。2组膝关节的PTA及FTA值均随膝屈曲角度的增而减小,试验组中诊断为髌骨半脱位的21膝的CA值随着屈膝角度的增大而减小。结论 PTA、CA、FTA值可以在动态MRI技术中定量评价髌股关节,动态MRI技术不仅能反映髌股关节的异常排列程度,还可以提供异常程度的动态变化趋势;动态MRI技术通过对膝关节屈曲过程的连续成像可得出髌股关节的运动轨迹。

Objective To analyze the value of dynamic MRI on the abnormal patellofemoral joint for the diagnosis of the patellofemoral disorder and the reliable information provided for the clinicians. Methods 30 patients （total 43 knees）with patellofemoral disorder as the experimental group, 15 healthy volunteer（ total 30 knees） as the normal control group. Two groups were respectively examined with the knee in 0° ,6°, 12°, 18° ,24°, 30° ,36° of flexion. The patellofemoral alignment was evaluated by measuring the patellar tilt angle （ PTA ）, congruence angle （CA） ;and femoral trochlear angle （FTA） during knee flexion from 0 degree to 36 degrees. The measurements were statistical analyzed and compared with the knee in different angle among the two groups. Results There were significant differences in PTA , CA and FTA between the experimental group and the normal control group at all angles of knee flexion （ P 〈 0.05 ）. The measurements of PTA, FTA decreased with the knee flexion＇ s increasing in the two groups. The measurements of CA decreased during the knee flexion＇ s increasing in the 21 knees which diagnosed patellar subluxation. Conclusion The measurements of PTA,FTA and CA can be used as indicators to quantitative evaluated the patellofemoral joint in dynamic MRI technique. The dynamic MRI technique can not only reflect the unusual arrangement of the patellofemoral joint, but also provide the dynamic change of unusual arrangement, and we can obtain the tracking of the patellofemoral joint through the process of continuous imaging.