To Compare The Effect Of Patellar Tracking After Total Knee Arthroplasty Between Midvastus Approach And Medial Parapatellar Approach

Objective: Because the patellar tracking is poor after total knee arthroplasty,the knee joint pain and instability resulted in the improvement of revision rate of total knee arthroplasty.The surgical approach is closely related to the excellent postoperative patellar tracking.The purpose of this study is toevaluate the effect of midvastus approach and medial parapatellar approach on patellar tracking after total knee arthroplasty.Methods: A total of 70 patients had unilateral knee arthroplasty in the joint surgery of our hospital from July 2015 to August 2016 were selected and randomly divided into A group(accept knee arthroplasty by midvastus approach)and B group(accept knee arthroplasty by medial parapatellar approach),35 cases in each group.All patients were treated with standard total knee arthroplasty(TKA),with the same type of prosthesis,and no patellar replacement and lateral support were performed in the surgery.1.The CT scan of group A and group B were performed before and after operation,and the posterior condylar Angle of the femur was measured,and the difference between the two groups before and after operation was compared.2.Patellar axial radiograph was performed preoperative operation and six months after operation,measuring A,B two groups of patients in the knees at 30 ° and 60 ° of patellar tilt Angle,patellar lateral translation angle,congruence angel,Comparing the difference of patellar tilt angel,patellar lateral translation angle,congruence angel between A group and B group when the knee at 30° and 60° in preoperative operation and six months after operation,analyzing the change of the patellar tracking.3.The patient's patella Feller score and knee joint KSS score were evaluated in preoperative operation and six months after operation,nd the difference between the patella Feller score and the knee KSS score was compared between the two groups.4.The X-ray of the knee joint was taken whether the patella fracture was or not observed in group A and group B after operation.SPSS17.0 statistical software was used to analyze the data,and the measurement data was denoted by mean value±standard deviations.Res?lts: A total of 70 cases of knee joint were analyzed in both groups A and B.1.Comparing posterior condylar angel between A group and B group before and after the operation,the difference was not statistically significant(P>0.05).2.Comparing patellar tilt angel,patellar lateral translation angle,congruence angel between A group and B group when the knee at 30° and 60° before surgery,the difference was not statistically significant(P>0.05);while 6 months after surgery,The patellar tilt angel,patellar lateral translation angle,congruence angel with the knee at 30° and 60° were significantly different(P<0.05).3.Comparing knee joint KSS score between A group and B group preoperative operation and six months after operation,the difference was not statistically significant(P>0.05).Comparing patella Feller score before operation,the difference was not statistically significant(P>0.05),and the difference was statistically significant(P<0.05)at six months after operation.4.There was no patellar fracture in both groups A and B.Conclusion: Total knee arthroplasty by midvastus approach works better for patellar tracking.It is expected to reduce postoperative complications of patellofemoral joint due to poor patellar tracking and improve the curative effect.