Accuracy of analog two-dimensional and digital three-dimensional preoperative templating for predicting implant size in total knee arthroplasty / 中国组织工程研究

ABSTRACT

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.