Influence of tibial component rotation on short-term clinical outcomes in Oxford mobile-bearing unicompartmental knee arthroplasty

MA Peng-gang; YANG Yong; MA Long; FENG Gang-ning; JIN Qun-hua

doi:10.3969/j.issn.2095-252X.2025.06.010

Abstract：Objective To observe the effect of axial rotation of tibial component on the short-term clinical outcomes after Oxford mobile-bearing UKA(OUKA)by a short-term follow-up.Methods From December 2020 to June 2021,this study included 54 patients(55 knees)with severe Anteromedial osteoarthritis(AMOA)who underwent OUKA treatment at our hospital.The Oxford Knee Score(OKS),the Knee Society Score-Knee(KSSK),and the Knee Society Score-Function(KSSF)were assessed preoperatively,and and then after the first month,third month,sixth month and eighteenth month.In the axial plane of CT,postoperative tibial component rotation angle was assessed using vertical line of the surgical epicondylar axis(SEA)as reference line postoperatively.External rotation of the tibial component relative SEA line was considered a positive value,and internal rotation of the tibial component was considered a negative value.The changes of OKS,KSSK and KSSF score before and after surgery,and the correlation between the axial rotation angle of the tibia component with the OKS,KSSK and KSSF scores in eighteenth month postoperatively was analyzed.Results The axial external rotation angle of the tibial component in the group was-5.27°-14.49°,with an average of(4.95±5.27)°.The OKS,KSSK,and KSSF scores in the third month,sixth month and eighteenth month after surgery were significantly improved compared with those before surgery(P<0.05).The axial rotation angle of the tibia component was positively correlated with the OKS score in the postoperative eighteenth month(the higher the OKS score,the worse the clinical outcomes).There was no significant correlation between the rotation angle of the tibia component with the KSSK and KSSF scores in the eighteenth month after surgery.Conclusions The axial rotation of the tibial component after OUKA has important effects on the clinical outcomes.The postoperative tibial component tends to be externally rotated,and the clinical outcomes are poor when the external rotation angle is too large.