A Comparative Study Of The Mid-term Results Of Medial Pivot And Posterior Cruciate-Stabilizing Knee Prosthesis After Total Knee Arthroplasty

Objective To compare the postoperative mid-term effect,satisfaction and the incidence of related complications of Medial pivot(MP)and Posterior cruciate-prosthesis(PS)in the Chinese population with Total knee Knee Arthroplasty(TKA).And to systematically evaluate the clinical application of medial pivot knee prosthesis.Methods 120 patients who underwent a unilateral TKA with the MP(Wright Medical)(n=60)and PS(Zimmer Medical)(n=60)operated by the same physician with a year follow-up from 2010 to 2011 were chosen.Preoperative and postoperative movement-evoked and resting pain,range of motion,muscle strength,flexion deformity and function HSS were recorded and made a comparison.Statistical analysis of every indicators was performed.Evaluating the application outcomes and postoperative satisfaction with WOMAC(The Western Ontario and Mc Master Universities)system.Results(1)19 patients were lost to follow-up,leaving 49 cases in the group of Wright and 51 cases in the group of Zimmer.The patients had no complaint except for one patient of the lost in group Zimmer dead of medical diseases at 2 years post-surgery.(2)No significant differences from baseline were identified between the two groups in terms of age,BMI,preoperative ROM,as well as follow-up period(P>0.05).(3)No differences for the movement-evoked and resting pain,range of motion,muscle strength,flexion deformity and function HSS in the preoperative and postoperative were observed(P>0.05).(4).No differences were found in patient postoperative satisfaction between two groups(P>0.05).(5).None of the knees demonstrated revision and periprosthetic infection following total knee arthroplasty in the 5 years follow-up period.(6)a total of 101 patients had no complaint except for 1 knee that showed pain in the MP group.Conclusion 1.There were no statistically significant differences in improvement of postoperative mid-term effect,satisfaction and the rates of loosening,revision and periprosthetic infection.Patients with the MP prosthesis experienced satisfactory pain relief and a functional recovery,providing functional recovery similar to those of the Posterior Cruciate-Stabilizing knee prosthesis.2.Compared with the traditional knee replacement system,the medial pivot knee prosthesis improved the stability of joint motion in clinical by the design of structure closed to the knee join anatomy.The medial pivot knee prosthesis TKA with the disadvantage of operation and bone preservation for the design of less intercondylar osteotomy provide benefit in revision arthroplasty.3 The pain and discomfort one patient complained of may result from over-tiredness.4.It’s important to do a longer follow-up for the lifetime of the wearing of polyethylene insert and long-term rate of revision of the medial pivot knee prosthesisin longer follow-up.