三维CT扫描评价股骨滑车发育不良的应用研究

The Evaluation of Femoral Trochlear Dysplasia Using Imaging Analysis System Based on Three-Dimension Computed Tomography

目的:评估膝关节三维CT扫描结合MIMICS图像分析系统与X线平片在评价股骨滑车发育不良中的差异及其临床应用价值。方法:2013年5月至2014年1月,连续30例诊断为复发性髌骨脱位患者接受手术治疗。患者术前均接受膝关节三维CT扫描,采用MIMICS图像分析系统进行处理并计算股骨滑车突起指数。患者术前接受膝关节X线透视检查,获得纯侧位X线片,测量股骨滑车突起指数。对比两种评估方法结果的差异。以X线片测量方法为标准,计算三维CT分析方法的敏感性、特异性、阳性预测值以及阴性预测值。结果:30例患者采用膝关节侧位X线片方法评价股骨滑车突起指数均值为5.3±1.8 mm(3.2至8.4 mm)。膝关节三维CT扫描评价股骨滑车突起指数平均为5.2±1.5 mm(3.5至8.1mm)。两种测量方法结果的差异无统计学意义(P=0.846>0.05)。以X线片方法为标准,三维CT评估方法的敏感性、特异性、阳性预测值以及阴性预测值分别为89.5%、81.8%、89.4%、82.0%。结论:膝关节三维CT扫描评估股骨滑车发育不良能够获得良好的敏感性、特异性。与膝关节侧位X线片评估方法所得结果无显著差异。CT影像技术能够提供更简便、安全的评估途径。

Objective To evaluate the application of imaging analysis system based on three-dimen- sion computed tomography （3D-CT）for the diagnosis of femoral trochlear dysplasia. Methods Between May 2013 and January 2014,30 patients were diagnosed as recurrent patella dislocation and received surgical treatment. All the patients received 3D-CT diagnosis of the knee joints preoperatively,and the data of 3D-CT were transferred to imaging analysis system with MIMICS software that would be used to get the trochlear dysplasia index. The patients were also received knee fluoroscopic detection. A true lateral view was also used for evaluation of the trochlear dysplasia as the classic method. The dif- ference between the two methods was compared. And the sensitivity, specificity, positive and negative predictive value of the imaging analysis system were analyzed. Results The mean trochlear dysplasia index was 5.3± 1.8 mm （3.2 to 8.4 ram）using the classic fluoroscopic method,showing no significant difference from the result according to the imaging analysis system,5.2 ±1.5 mm （3.5 to 8.1 mm）. When the fluoroscopic method was set as the golden standard, the sensitivity, specificity, positive and negative predictive value of the imaging analysis system were 89.5% ,81.8% ,89.4% and 82.0% respec- tively. Conclusion The imaging analysis system based on 3D-CT of knee joints could provide acceptable results without good sensitivity and specificity,without significant differences from the classic fluoro- scopic method, So it is a more safer and easier approach worthy of clinical implication.