Correlation Study Between The Coronal Varus-Valgus Angle Of Femoral Component And The Short-Term Clinical Outcome After Oxford Unicompartmental Knee Arthroplasty

Objective To clarify whether there is a correlation between the coronal varus-valgus angle of the Oxford UKA femoral component and the short-term clinical outcome of patients by observing patients’ short-term follow-up after Oxford UKA.Methods The general data were collected from patients within the indication who were proposed to undergo Oxford knee unicompartmental arthroplasty in our hospital.The femoral component coronal angle(FCCA),femoral component sagittal angle(FCSA),femoral component axial angle(FCAA)were measured from the knee anteroposterior X-ray radiograph,total-leg X-ray radiograph and computed tomography of the knee,postoperatively.The Oxford knee score(OKS),the American knee society score for clinic(KSSc),the American knee score for function(KSSf)and the range of motion(ROM)of the knee were estimated preoperatively,1-month postoperatively,3-month postoperatively,6-month postoperatively,respectively.Patients were devided into groups according to their FCCA,and the differences of FCSA,FCAA among groups were compared.OKS,KSSc,KSSf,ROM among groups at different assessment time were compared.The correlation between FCCA and OKS,KSSc,KSSf and ROM at each time was analyzed.Results There were 62 patients finally enrolled in the statistical analysis.The patients were grouped according to the coronal angle of the femoral prosthesis,with-6° to-2° being the valgus group,-2° to 2° being the neutral group,and 2° to 6° being the varus group,with 17 cases.ANOVA showed that P=0.324>0.05 for age,P=0.944>0.05 for height,P=0.597>0.05 for weight,P=0.548>0.05 for BMI,P=0.132>0.05 for FCSA,and P=0.168>0.05 for FCAA,neither of which was of statistical significance.Within FCCA groups,there was no significant difference comparing OKS,KSSc,KSSf and ROM in total stages of follow-up time between different groups as P>0.05.At each follow-up time,there was no significant difference of OKS,KSSc,KSSf and ROM among groups as P>0.05.Combined FCCA groups,there was a statistical significance at different follow-up time as P<0.05.The correlation analysis between FCCA and OKS,KSSc,KSSf and ROM at each follow-up time showed low correlation results as P>0.05.Conclusion For patients with anteromedial osteoarthritis,undergoing Oxford knee unicompartmental arthroplasty can relieve joint pain,improve joint function,and improve quality of life in the early postoperative period.As it going,there was a gradual improvement of patients’ postoperative clinical perceptions within 6 months postoperatively.Within a certain toleration range,there was no significant correlation between the degree of femoral component coronal varus-valgus angle and the short-term clinical functional improvement of the patients.