Effects Of Femoral Lateral Bowing On Coronal Alignment In Total Knee Arthroplasty

Objective:To evaluate the effect of femoral bowing on coronal alignment in total knee arthroplasty,and whether the application of navigation can significantly improve postoperative limb alignment,component position,functional score and knee joint activities in patients with femoral bowing.Methods:A total of 154 patients that received TKA from July 2014 to December 2017 in our hospital diagnosed with knee osteoarthritis with femoral bowing.Among them,there were 24 males and 68 females in the conventional group,aged 55~81(66.78±5.93)years old,and BMI was 16.88~28.44(22.28±3.17)kg/m~2.There were 10 males and 52 females in the navigation group,aged 50~78(65.06±8.53)years old,with BMI of 17.90~31.25(22.74±3.11)kg/m~2,follow-up period was not less than 12 months.Collecting preoperative/postoperativemechanicalfemorotibialangle(mFTA),femoralbowing angle(FBA),mechanical lateral distal femoral angle(mLDFA),mechanical medial proximal tibial angle(mMPTA),postoperative medial distal femoral angle(?)and postoperative medial proximal tibial angle(?),preoperative/postoperative KSS score,preoperative/postoperative WOMAC score,preoperative/postoperative Oxford score after operation,preoperative/postoperative knee joint activities.Radiological results,functional scores and range of motion of the knee were compared between the two groups.Results:(1)Compared with gender distribution,age,BMI,hospitalization days and hospitalization costs in two groups,there was no significant difference between the two groups(P>0.05);The data about operation time between the two groups was significant difference(P<0.05).(2)The difference of postoperative mFTA between the two groups was significant(P<0.05);(3)In 0°<FBA?5°patients,compared preoperative(mFTA?FBA?mLDFA and mMPTA)and postoperative(mFTA,?and?),the difference was no significant(P>0.05).In patients with 5°<FBA?10°,the preoperative(mFTA,FBA,mLDFA and mMPTA),and the comparison of postoperative angle???,the difference was no significant(P>0.05);In patients with FBA>10°,the difference of postoperative mFTA was significant(P<0.05),and the mean value of the conventional group was higher than that of the navigation group;(4)Comparison of outlier rate between two groups,navigation group showed a lower rate of outliers in postoperative mFTA and?than conventional group(5)In the conventional group,FBA was positively correlated with postoperative mFTA,and negatively correlated with?.No correlation between preoperative and postoperative measurements was found in the navigation group;(6)Postoperative KSS score,WOMAC score,Oxford score and knee range of motion were improved than before the operation,but the scores and knee range of motion comparison,but the difference was not significant(P>0.05).Conclusion:Femoral bowing may affect the reconstruction of postoperativelimb alignment and the placement of component.Despite measuring FBA before the conventional TKA,and takingsome adjustments during surgery,outliers about postoperative limb alignment and the placement of component will occur.The application of navigation technology can better improve postoperative limb alignment and the placement of component,but there is no obvious advantages postoperative functional scores and knee range of motion in short term.