Comparison Of Anterior Knee Pain Between Medial Pivot And Posterior Cruciate-stabilizing Knee Prosthesis After Total Knee Arthroplasty

Objective To compare patellar position relationship and its influence on anterior knee pain between Medial pivot(MP)and Posterior Cruciate-stabilizing(PS)knee prosthesis after total knee arthroplasty(TKA)? so as to study the effect of knee prosthesis on patellofemoral join.Methods Retrospective study analysis 65 patients(95 knees)underwent total knee arthroplasty in our hospital from September 2017 to August 2018.Among which 32patients(47 knees)were treated with Medial pivot knee prosthesis(MP group),and 33patients(48 knees)were treated with Posterior Cruciate-stabilizing knee prosthesis(PS group).axial radiographies of patella with knees flexing at 45 degrees and Positive lateral X-ray examination were taken and modified Insall-Salvati index,patellofemoral congruence angle(CA)and patellar tilt angle(TA)were measured preoperatively and postoperatively.Postoperative efficacy was evaluated through outpatient consultation or telephone follow-up.According to Felle scoring criteria,preoperative and postoperative knee pain score and patella score were performed.General data of the two groups were compared,the difference was not statistically significant(P>0.05).Preoperative and postoperative follow-up results were sorted out,and SPSS 24.0 statistical software was used for statistical comparison and analysis.Results 62 patients(91 knees)were successfully followed up,among which 31patients(46 knees)in MP group were followed up for 6-12 months with an average follow-up of(9.3±1.7)months,and 31 patients(45 knees)in PS group were followed up for 6-12 months with an average follow-up of(9.6±1.7)months.Postoperative delayed wound healing occurred in 1 case.unilateral(operative side)calf tendon vein thrombosis occurred in 3 cases,and poor function and ankylosis of the knee and underwent manual release under anesthesia occurred in 2cases.At the last follow-up,the mean value of the modified insall-salvati index in the MP group was 1.5±0.1,and the mean value of the modified insall-salvati index in the PS group was 1.6±0.1.There was no significant difference between the two groups(P>0.05).the mean value of the patellofemoral congruence angle in the MP group was(0.8±10.0),and the mean value of the patellofemoral congruence angle in the PS group was 3.1°±9.5°.There was no significant difference between the two groups(P>0.05).At the last follow-up,the mean value of the patellar tilt angle in the MP group was 4.2°±3.4°,and the mean value of the patellar tilt angle in the PS group was 4.9 ° ±3.2°.There was no significant difference between the two groups(P>0.05).At the last follow-up,the mean value of the knee pain score and patella score in the MP group was 12.2±2.7 and 24.5±3.4,and the mean value of knee pain score and patella score in the PS group was 11.9±2.9 and 23.4±3.1.There was no significant difference between the two groups(P>0.05).Conclusion There was no significant difference in the incidence of anterior knee pain and patella position between Medial pivot and Posterior Cruciate-stabilizing knee prosthesis after total knee arthroplasty.Theoretically,the Medial pivot knee prosthesis is more superior in patellofemoral joint design,but its clinical efficacy needs to be further studied by multi-center and large samples.