Clinical Study On The Relationship Between Sagittal Position Of Femoral Prosthesis And Postoperative Anterior Knee Pain

Objective: This study aimed to study the relationship between the sagittal position of the femoral prosthesis and prepatellar pain after total knee arthroplasty(TKA).Methods: The patients who visited the clinic between September 2018 and November2019 were screened out,and the first unilateral knee replacement was performed in Affiliated Zhongshan Hospital Of Dalian University 100 patients(100 knees)met the criteria due to osteoarthritis of the knee.All patients did not replace the patella prosthesis.After the operation,the patient was treated with analgesic and anticoagulant drugs,and the lower limb joint rehabilitation device was used to help the patient move early.The patients were grouped by measuring the standard lateral femoral prosthesis flexion angle(FPFA)after the operation:anterior Extension group(-3°≥FPFA>0°),neutral group(0°≥FPFA>3°)andr flexion group(3°≥FPFA>6°).KSS,VAS,Feller score,to evaluate the pain degree and functional status of the knee joint before and after TKA.Results: All patients were able to walk normally and their knee function met their daily needs.After analyzing the three groups,no differences in gender,or age between the extension group,neutral,and flexion groups.After measured the angle between the femoral prosthesis and the femur,after statistical analysis,(p>0.05).After comparing the KSS function,clinical score,and Feller score of the extension group,the neutral group,and the flexion group,it was found that each group improved compared with preoperatively(p<0.01).The 12-month VAS scores of the forward flexion group,the neutral group,and the flexion group were not different after comparison between the groups(p>0.05).There was no difference of spostoperatively KSS clinical score between extension and flexion groups with the neutral group(p>0.05),but difference in the extension and flexion groups(p<0.05).The postoperative KSS functional scores in the extension group were significantly lower and statistically different from those in the neutral and posterior flexion groups after comparison(p<0.05).The incidence of pain at 12 months postoperatively in the extension group was: 26.7%(8/30);the incidence of pain at 12 months postoperatively in the neutral group was:5%(2/40);and the incidence of pain at 12 months postoperatively in the posterior flexion group was: 10%(3/30).The flexion group was higher than neutral group(P<0.05).Conclusions: In total knee arthroplasty,sagittal placement of the femoral prosthesis has an effect on postoperative anterior patellar pain;anterior flexion placement of the femoral prosthesis increases the incidence of postoperative anterior knee pain;in total knee arthroplasty,this study recommends placing the femoral prosthesis in a neutral position 0-3°.