Comparison Of Early Patellofemoral Joint Function Between Total Knee Arthroplasties Using Medial Pivot And Posterior-Stabilized Prosthesis

PurposeTo compare the clinical and radiological outcomes of the patellofemoral joint total kneearthroplasty using the Medial Pivot(MP)knee prosthesis and the Posterior-Stabilized(PS)knee prosthesis.Systematically evaluate the application of the patellofemoral joint design of the Medial Pivot knee prosthesis in the Chinese population.MethodsFrom May 2017 to December 2017,110 patients with knee joint replacement due to knee osteoarthrosis were included in the study.The Medial Pivot knee prosthesis(set as MP group)and the classical Posterior-Stabilized knee prosthesis(set as PS group)were each selected by 55 patients,followed up to 1-year after surgery.The KSS score,WOMAC score,Kujala score,knee joint range of motion and image results were compared between the two groups at 1-year follow-up.The difference between the above indicators in the MP group and the PS group was compared with the preoperative evaluation,and statistical analysis was performed to evaluate the improvement degree of each index,and the effect of the patellofemoral joints when the two prostheses were applied in the Chinese population was evaluated.The incidence of patellofemoral joint-related complications in the early stage were also compared between the two groups.Results1.Actually 98 people were followed up,including 50 in the MP group and 48 in the PS group;2.There were no significant differences in the age,gender,BMI,KSS score,WOMAC score,Kujala score,range of motion,and loss of follow-up rate between the two groups(P>0.05).3.There was no significant difference in KSS score and WOMAC score between the two groups(P>0.05).There was no significant difference in the improved amount of KSS score and WOMAC score between the two groups(P>0.05).4.There was a statistically significant difference in Kujala score between the two groups(P<0.05).There was a statistically significant difference in the increased amount of Kujala score between the two groups(P<0.05).The Kujala score and the increased amount of Kujala score of the MP group was better than the PS group.5.There was a statistically significant difference in knee joint range of motion between the two groups(P<0.05).There was a statistically significant difference in the increased amount of knee joint range of motion between the two groups(P<0.05).The knee joint range of motion and the increased amount in the PS group was better than MP group;6.There was no statistically significant difference in the patellar tilt angle and Patellar translation between the two groups at 1 year after operation.There was no significant difference in the change of patellar tilt angle between the two groups(P>0.05).7.One year after the operation,there were 1 case of anterior knee pain and 2 cases of patellar clunk syndrome in the MP group.There were 2 cases of knee pain and 4 cases of patellar clunk syndrome in the PS group.There was no significant difference in the incidence of complications(P>0.05),there was no periprosthetic joint infection and aseptic loosening in both groups.Conclusion1.The Medial Pivot knee prosthesis is designed to restore the kinematic function of the physiological knee joint,and to gather a variety of design features that are beneficial to reconstruct the normal patellofemoral joint relationship,and can provide a good patellofemoral function for the patient.2.The Medial Pivot knee prosthesis is inferior to the Posterior-Stabilized knee prosthesis in terms of postoperative activity,but in general,the Medial Pivot knee prosthesis can be similar in knee function and postoperative satisfaction to the Posterior-Stabilized prosthesis in total knee arthroplasty.3.There was no statistically significant difference in the imaging changes of the patellofemoral joint and the incidence of related complications between the Medial Pivot knee prosthesis and the Posterior-Stabilized knee prosthesis.4.The Mid-and-long term patellofemoral joint function of the Medial Pivot knee prosthesis still needs further follow-up.