| Background and ObjectiveUnicompartmental Knee Arthroplasty(UKA)is an effective method for the treatment of unicompartmental osteoarthritis of the knee joint.With the improvement of the technique of Unicompartmental Knee Arthroplasty and the continuous improvement of the design of the Unicompartmental Knee Arthroplasty joint prosthesis,Unicompartmental Knee Arthroplasty technique became more and more successful,and complications gradually decreased.After a large number of medium and long-term follow-ups,the mid-term survivorship rate of the prosthesis was significantly increased.UKA can relieve the patient’s knee joint pain,improve the function of the knee joint,restore the patient’s ability to work,and improve the patient’s quality of life.With the increasing proportion of aging population in our country,patients with knee osteoarthritis gradually increase.Which is due to the mechanical properties of the knee joints,the medial compartment receives 65% of body gravity,and the lateral compartment receives 35% of body gravity.The incidence of medial compartment osteoarthritis is highest in knee osteoarthritis.Traditional total knee arthroplasty has large trauma and more soft tissue dissection,resulting in more blood loss during surgery and postoperative and high blood transfusion rate;early postoperative severe pain caused by surgical trauma,allowing the patient to bear physiologically and psychologically With great pain,patients have psychological fears and do not dare to perform active or passive rehabilitation exercises,which greatly delays the recovery of patients.With the continuous advancement of Unicompartmental Knee Arthroplasty technology and the current concept of rapid rehabilitation clinically proposed,the concept of "knee conservation" is proposed,without destroying the original proprioception and soft tissue balance system of the patient’s own knee joint,the patient’s knee joint kinematic function can be retained to the maximum extent,and the postoperative patient satisfaction can be improved.Unicompartmental Knee Arthroplasty is increasingly favored by Chinese orthopedic specialists.The currently used UKA prosthesis is divided into two major types according to the bearing of the prosthesis: fixed-bearing(FB)and mobile-bearing(MB).There are few reports on comparative studies between the two prostheses.There is no definite evidence to show whether postoperative patients’ knee joint function and the mid-term survival rate of the two prostheses are statistically different.The kinematics design of the mobile-bearing prosthesis is closer to the mechanical characteristics of the knee joint,the polyethylene bearing is subjected to lower pressure and lower wear rate,but the dislocation rate of the mobile-bearing relative to the fixed-bearing is significantly higher.Due to the differences in the design concept and surgical procedure of UKA of the two bearings,the surgical procedure of the mobile-bearing is cumbersome and complicated.The experience of the operator is high,the learning curve is long.But the surgical procedure of the fixed-bearing is easily operated.The procedure is similar to that of total knee arthroplasty.Beginners are easy to learn.Therefore,the orthopedic experts still have greater disagreements and controversies in choosing the mobile-bearing prosthesis or the fixed-bearing prosthesis.In recent years,our department has successfully operated hundreds of cases of medial Unicompartmental Knee Arthroplasty,and most patients have achieved good clinical results after surgery.In order to study the effect of two UKA prostheses on the treatment of simple medial compartment knee osteoarthritis,whether the early clinical outcomes,Radiographic Outcomes,and postoperative complications were different after surgery,the study was selected patients from June 2014 to October 2017,a retrospective study of patients with unilateral UKA data were 40 cases.Methods A retrospectively clinical study was performed in 40 patients who with the medial compartment osteoarthritis of the knee from June 2014 to October 2017 in The First Affiliated Hospital of Zhengzhou University.According to the patient’s UKA polyethylene,the 40 patients are divided into two groups,25 patients in the mobile-bearing(MB)group;15 patients in the fixed-bearing(FB)group.All patients were followed up to 6 months postoperatively.Two patients in the MB group withdrew from the study because they couldn’t follow clinical indicators after revision due to failure.Both groups were performed by the same experienced joint surgeon.Patients in the MB group used a third generation Oxford? Partial Knee with an Oxford high-flexion mobile-bearing,and patients in the FB group used a Zimmer? high-flexion fixed-bearing single-sacral prosthesis.By comparing the two groups of patients with postoperative clinical outcomes,including the length of the surgical incision,the procedure of operation time,the drop of hemoglobin on first day of postoperative,the Visual Analogue Scale on the first day of postoperative;the range of movement of kneeand New York’s Special surgical Hospital for Special Surgery knee function score of patients in postoperative 3 months,6 months;postoperative Hip-Knee-Ankle angle and leg alignment angle;postoperative radiographic outcomes and postoperative complications.Data statistical analysis was carried out using SPSS 21.0 software.The K-S test was used to test whether the quantitative data were normally distributed.Measured data with normal distribution were expressed as the mean±standard deviation(?X±S).The data between the two groups were compared using independent samples t-test;ROM knee motion and HSS knee score repeated measurements using repeated measuresANOVA.The ROM and HSS knee function scores of knee joint activity was performed using multivariate analysis of variance(MANOVA)at the same time point.Count data are expressed as the number of cases(n)or percentages(%)of the observations for each group,using the χ2 test.P<0.05 was considered statistically significant.Results After follow-up,two patients in the MB group had not completed follow-up due to postoperative complications.The remaining two groups were completed followed up.The length of surgical incision,the procedure of operation time,the drop of hemoglobin on the first postoperative day,and the pain visual analog scale(VAS)on the first postoperative day were not statistically significant(P>0.05).The knee ROM and knee HSS scores at the 3rd and 6th months after surgery were compared with preoperative knee ROM and knee HSS scores.After repeated measures ANOVA,the differences had statistically significant(P<0.05);The ANOVA for repeated measures The ROM and knee HSS scores at 3 months and 6 months after surgery in both groups were compared by multivariate analysis of variance(MANOVA),The differences were not statistically significant(P>0.05);After 6 months of imaging evaluation index comparison,according the independent samplet-test,the B-angle and the F-angle,the difference had not statistically significant(P>0.05).The A-angle and the E-angle,the differences had statistically significant(P<0.05).The incidence of postoperative complications between the two groups of patients,the difference had not statistically significant(P>0.05).However,there were two cases of early failures were revisived in the MB group.Conclusions The mobile-bearing and fixed-bearing prosthesis can relieve the pain of patients with medial compartment osteoarthritis and obtain good knee joint motion and kneefunction.Postoperative imaging assessment,on the posteroanterior radiograph,the A-angle and the E-angle,the difference was statistically significant,and the defect rate of the femoral component and the tibial component of the MB group was higher than that of the FB group.There was no statistical difference in the incidence of early overall complications between the two groups,but the rate of early revision in the MB group was higher than in the FB group. |
PDF Full Text Request