Medial unilateral knee arthroplasty after high tibial osteotomy: A retrospective study of 41 cases

Introduction: When medial knee osteoarthritis continues to get worse after a high tibial osteotomy (HTO) procedure, a subsequent total knee arthroplasty (TKA) is typically warranted. Medial unilateral knee arthroplasty (UKA) is not recommended. The aim of this study was to evaluate the outcomes of patients who underwent medial UKA after HTO.Hypothesis: Good results can be obtained with this procedure, as long as the postoperative valgus is not excessive.Materials and methods: This was a retrospective, single-center study of patients operated between Jan-uary 2005 and June 2019. The primary endpoint was the Oxford Knee Scale (OKS). The Knee injury and Osteoarthritis Outcome Score (KOOS) and the Western Ontario and McMaster Universities osteoarthri-tis index (WOMAC), range of motion and complications were the secondary endpoints. The average follow-up was 79 months.Results: Forty-one knees in 38 patients were analyzed. Four revisions with implant exchange (10%) were needed. Thirty-seven knees had a mean OKS of 20/60 +/- 8 (12-39). The mean flexion and extension ampli-tude were 123 degrees +/- 8 degrees (110-140) and - 1.5 degrees +/- 4 (-15-0), respectively. Eight patients had flexion and/or extension contractures.Discussion: Good functional and clinical outcomes in the medium term were achieved for the patients in this study who underwent UKA after HTO. These findings reinforce the good results reported in recent studies of UKA after HTO.Level of evidence: IV, Retrospective study.(c) 2022 Elsevier Masson SAS. All rights reserved.