Prosthesis size in total knee arthroplasty predicted using digital pre-operative plan / 中国组织工程研究

ABSTRACT

BACKGROUND:Differences of knee anthropometry between individuals are significant, while preoperative templating is not accurate in predicting the prosthesis size. OBJECTIVE:To improve the accuracy of pre-operative plan in predicting the prosthesis size in total knee arthroplasty using digital technologies. METHODBetween January 2013 and May 2004, 50 patients (20 men and 30 women;aged 54-82 years;mean age, 67.8 years) received primary total knee arthroplasty for osteoarthritis and were retrospectively analyzed. According to the treatment, the patients were divided into two groups. The digital group, a series of 21 patients, underwent 64-row MDCT before total knee replacement. CT images were imported into Mimics, and three-dimensional models of femur and tibia were reconstructed. Then, computer-aided design files of different sizes of prostheses provided by the manufacturers were imported into Mimics, too. Surgical simulation of osteotomy and prostheses implantation were performed in Mimics, component size was determined by the contour of distal femur and proximal tibia. The control group, a series of 29 patients, underwent primary total knee arthroplasty using conventional approaches. The agreement between preoperative plan and the actual prosthesis size was assessed during the surgery. Postoperative X-ray of low limb was taken to evaluate the accuracy of sizing and the efficacy of digital technologies was assessed. RESULTS AND CONCLUSION:The intraoperative and postoperative evaluation showed inaccurate sizing of femoral and tibial components in 1 case in digital group and in 11 cases in conventional group. The accuracy of prediction was 95%in digital group and 62%in conventional group, with significant differences between the two groups (P<0.05). Four overhanging and two notching cases were observed in conventional group, but none in digital group. The digital technologies provide an effective means for accurate prediction of prosthesis size and personalized surgical simulation.