Comparison Of IAssist Navigation System And Traditional Method For Total Knee Arthroplasty

Objective: To compare and analyze the postoperative alignment of lower-extremity mechanical axis and clinical efficacy between iAssist Navigation system and traditional methods in performing total knee arthroplasty(TKA).Method:25 patients of knee osteoarthritis who underwent TKA in our hospital from January 2016 to September 2017 were enrolled,including 12 patients in the iAssist group and 13 patients in the traditional group.The characteristics of the two groups had no significant difference.The target mechanical femorotibial angle(mFTA),the mechanical lateral distal femoral angle(mLDFA)and the medial proximal tibial angle(MPTA)were 180°,90°,90°.Thus,the absolute value of the difference between the actual measured value and the target value of the two groups after operation and the operation time,intraoperative blood loss and postoperative drainage were compared.Meanwhile,the range of motion of the knee(ROM),Hospital for Special Surgery score(HSS),postoperative complications were compared.Result: The deviation of mechanical femorotibial angle of the iAssist group was less the traditional group(1.52±0.40°vs.2.14±0.67°,t=2.790,p=0.010),the deviation of mechanical lateral distal femoral angle(0.83±0.21°vs.1.50±0.33°,t=5.909,p=0.000)and medial proximal tibial angle(0.70 ± 0.25 ° vs.1.22 ± 0.42 °,t = 3.730,p= 0.001)were also less than the traditional group.The operation time of the iAssist group didn't have significant difference with the traditional group.Besides,the amount of intraoperative blood loss and the 24-hour drainage volume in the iAssist group was less than the traditional group.At the 12 th month after surgery,the HSS scores in the iAssist group and the traditional group were significantly higher thanthose before surgery(P<0.05),but the difference between the two groups had no statistical significance(p > 0.05).In terms of ROM,there was no significant difference between the two groups after the surgery,but both improved when comparing to those before surgery(P<0.05).There were no complications such as infection in either group.Conclusion:The alignment of lower-extremity mechanical axis in iAssist group was more accurate than the traditional group.The amount of intraoperative blood loss and 24-hour drainage volume in iAssist group was less than traditional group while the operation time was not increased in iAssist group.However,there was no significant difference in knee function and patients' satisfaction comparing to traditional method.Thus,long-term clinical outcome of iAssist Navigation system needs further observation.