The Early Clinical Effect Of Total Knee Replacement With Micro Port Medial-Pivot Knee System

Objective:To investigate the early clinical outcome of the TKA with Medial-Pivot Knee System.Methods : A retrospective analysis was carried out in treatment of 25 patients(33knees)using Medial-Pivot Knee System in The First Hospital Affiliated to Soochow University from 2016-03 to 2017-09,including 3 males(3 knees)and 22 females(30knees),aged 55-80 years,mean aged 69.5years.Most of the patients are involved in osteoarthritis and one of these patients is also with pigmented villonodular synovitis.One patient with traumatic arthritis is also included.The prosthesis was fixed with bone cement and the patella was not treated with replacement.Clinical results were evaluated preoperatively and postoperatively using KSS scoring system,Womac scoring system and we compared the range of motion(ROM)and monitored the complications,Operating time,blood loss and blood transfusion were observed.Results:All 25 patients were followed up for 6-22 months(average,12.7 months).The ranges of motion of knees were average 92.0 degrees preoperatively,and average102.2 degrees at the latest follow up examination,and the difference between thses data was statistically significant(P<0.01).The mean value of the scores according to KSS was average 48.1 preoperatively,and average 86.9 at the latest follow up examination,which were increased significantly(P<0.01).THe postoperative WOMAC scores of all 25 patients were lower than that before operation and the difference between thses data was also statistically significant(P<0.01).According to the KSS scoring system,the results were excellent in 24 cases,good in 9 cases and the excellent and good rate were as 100%.The mean operating time of 19 patients(21knees)undergoing unilateral total knee arthroplastyis 98.2±16.3min and 6 patients(12knees)undergoing bilateral TKA is 199.6±24.3min.The blood routine examination is made before and 3 days after operation.The mean Hb of all patients before operation is 122.7 ± 14.4g/L.And the mean Hb in patients undergoing unilateral TKA decreased from 121.3±16.1g/L to 102.6± 13.9g/L,the bilateral decreased from 127.8 ± 1.7g/L to 106.8 ± 17.6g/L.Most patients have been through the surgery successfully without transfusion.2 patients undergoing bilateral TKA have been transfused 2.5U and 3U MAP;2 patients undergoing unilateral TKA have been transfused2.5U and 3U MAP.The complications were few.At the latest follow up examination,all cases are not happened infection and prosthesis peripheral fracture.No evidence of translucent lines and periprosthetic osteolysis on the postoperative X-ray.No revision surgery for lining spin out,osteolysis and prosthesis loosening.Conclusions : The short term effect of MicroPort Medial-Pivot Knee System is satisfactory,while long term follow up is needed.