三维术前计划较二维模板测量更精确拟定人工膝关节置换假体型号

摘要

BACKGROUND:It is the key point to choose the right size of the prosthesis, and grasp the direction and thickness for osteotomy during total knee arthroplasty. In order to achieve the goal, accurate preoperative planning is very important. OBJECTIVE:To compare the accuracy of preoperative templating in total knee arthroplasty using conventional two-dimensional (2D) and computed tomography (CT)-based three-dimensional (3D) procedures (templating on 3D image&surgical rehearsing on rapid prototype technology-models), and to confirm the necessity of 3D evaluation for preoperative planning. METHODS:A total of 25 patients undergoing primary total knee arthroplasty were randomly selected, including 10 males and 15 females, at the age of 58 and 79 years old. 2D and 3D images were col ected from al patients. Preoperative templating was performed for each total knee arthroplasty using both conventional 2D radiographs and a CT-based 3D image model. Accuracies with regard to the predicted and actual implant sizes were determined for each procedure. RESULTS AND CONCLUSION:The 3D procedure was found to be more accurate in predicting implant size of 80%femoral and 72%tibial components than those of the 2D procedure (4%femoral and 12%tibial components). Significant differences in the consistent rate of femoral and tibial prosthesis models were detected significantly (P<0.05). Kappa coefficient statistics demonstrated that goodness of fit of prosthesis model was good in 3D preoperative templating. Results confirmed that the superiority of 3D preoperative templating over 2D conventional evaluation is in predicting implant size, and provides more comprehensive information on skeletal anatomy.%背景：依据病例的解剖结构选择合适的假体及大小型号，同时把握截骨角度方向及截骨厚度是关节置换手术的重要环节，这有赖于精确的术前计划。　　目的：对比基于二维影像的传统术前模板测量与三维术前计划(三维虚拟影像测量及快速三维打印模型实物测量、模拟手术)在人工膝关节置换假体型号拟定中的精确性差异，探讨三维术前计划的参考价值。　　方法：随机选择25例行初次全膝关节置换患者，其中男10例，女15例，年龄58-79岁，均完成二维及三维影像资料采集，进行二维影像模板测量与三维术前计划(针对三维虚拟成像、快速三维打印模型模拟截骨及假体置入操作)，分别拟定假体采用型号，膝关节置换中评估术前计划选择的假体型号与实际所需的一致性。　　结果与结论：三维术前计划对股骨侧及胫骨侧假体型号拟定的一致率分别为80%、72%，二维计划对股骨侧及胫骨侧假体型号拟定的一致率分别为4%、12%，两组股骨侧及胫骨侧假体型号拟定的一致率比较差异有显著性意义(P<0.05)。Kappa系数统计显示，三维术前计划的假体型号拟定吻合度较好。结果表明，三维术前计划较传统二维模板测量能更精确地拟定假体型号，提供更全面的骨骼解剖资料。