Early And Mid-term Results And Complications Of Oxford Unicompartmental Knee Arthroplasty

BackgroundWith the improvement of prosthesis design and the progress of surgical techniques,the clinical application of Oxford Unicompartmental knee arthroplasty(OUKA)has been increasing gradually.It is necessary to understand its early and mid-term efficacy through follow-up studies.At the same time,the occurrence of various complications during and after the operation should not be ignored.Furthermore,the causes and treatment strategies should be further studied and analyzed.ObjectiveTo explore the early and mid-term efficacy of Oxford Unicompartmental knee arthroplasty and its influencing factors,analyze the causes and treatment strategies of complications.MethodWe retrospectively reviewed 228 patients(273 knees)in the joint surgery department of our hospital from January 2010 to December 2018,including 65 males and 163 females,aged 50-83 years,with an average age of(65.34±7.64)years.They were treated with OUKA.Clinical and image outcomes were evaluated using femoro-tibial angle(FTA),range of motion(ROM),KSS pain score,KSS function score and OKS knee score.explore the influence of age,gender,BMI,type of prosthesis,postoperative follow-up time and whether the knee joint was operated at the same time on the improvement of evaluation indexes.Paired t test was used to compare the difference of evaluation indexes before and after operation.Repeated measures analysis of variance were used to evaluate the influence of various factors on the evaluation indexes before and after operation.Pearson correlation analysis was used to evaluate the relationship between postoperative follow-up time and Improvement degree of evaluation indexes.Repeated measures analysis of variance of two factors were used to evaluate the effects of simultaneous knee surgery on preoperative and postoperative evaluation indexes.The survival rate of the prosthesis was calculated.We recorded the complications during and after the operation in detail,analyzed the causes of complications,and summarized our experiences.ResultsThe mean follow-up time was(3.19 ± 1.98)years.At the time of the last follow-up visit,The tibial femoral Angle(FTA),range of motion(ROM),KSS pain score,KSS function score and OKS knee joint score were significantly improved compared with those before operation,and the differences were statistically significant(P<0.05).The age factor and ROM have an interaction effect,which means that the improvement of ROM in the younger group is better than that in the older group,and there is no difference in the improvement of other indicators between the age groups.BMI,gender,type of prosthesis,duration of postoperative follow-up,and whether both knees were operated at the same time did not significantly affect the results or the degree of improvement.In this study,the survival rate of OUKA was 98.9%.A total of 7 patients(7 knees)were found to have intraoperative or postoperative complications,with an incidence of 2.06%.There are two cases of Oxford prosthesis meniscus bearing dislocation,patients were treated with replacement of the bearing.One patient had poor wound healing after surgery,which was cured after Partial debridement and dressing change.There was 1 case of postoperative pain,patient was treated with total knee arthroplasty.One patient was found to have a tibial plateau fracture and was treated with cancellous bone screw.No other complications such as infection,deep vein thrombosis,pulmonary embolism,aseptic loosening of prosthesis were found in the patients included in the study.ConclusionsFor patients with medial compartment degeneration of the knee joint,OUKA has satisfactory early and middle clinical efficacy,can significantly relieve pain,improve range of motion and function of the joint,and improve the quality of life of the patients.Compared with patients over 60 years old,patients under 60 years old have better early and middle clinical efficacy after OUKA.The degree of obesity,gender,type of prosthesis,follow-up time and whether both knees were operated on at the same time had no significant effect on the surgical efficacy of OUKA.This study shows that the incidence of complications of OUKA surgery is not high,but the occurrence of complications should still be paid enough attention.The key to further improve the clinical efficacy of OUKA is to improve the perioperative management,prevent the occurrence of complications and properly deal with the existing complications.