Distal femoral varus osteotomy outcome: Is associated femoropatellar osteoarthritis consequential?

SummaryIntroductionDistal femoral varus osteotomy (FVO) can be indicated for young active patients who have lateral unicompartmental osteoarthritis in a valgus knee originating in the femur. However, its indication remains controversial when associated patellofemoral osteoarthrosis is present.HypothesisAssociated patellofemoral osteoarthrosis influences the results of osteotomy in cases of lateral tibiofemoral osteoarthrosis.MethodsTwenty patients (22 knees) underwent opening wedge FVO for lateral tibiofemoral osteoarthrosis of a valgus knee. The osteoarthrosis was lateral and unicompartmental in 11 cases, associated with patellofemoral osteoarthrosis in nine cases, and global in two cases. The osteotomy site was fixed with a 95° blade plate in all cases. At a mean follow-up of 54 months, all the patients were evaluated using the International Knee Society (IKS) score.ResultsEighteen knees had good or excellent results (80%), two had fair results (9.5%), and two had poor results (9.5%). One female patient underwent total knee replacement revision at 8 years and three others are awaiting total knee replacement. The mean preoperative IKS score increased from 49.28 (range, 14–70) to 74.23 (range, 41–92) at the last follow-up. The mean preoperative functional score increased from 50.68 (range, 30–80) to 72.85 (range, 40–90) at the last follow-up (p = 0.001). The 8-year survival rate was 91% (confidence interval, 69–100%). We noted improvement in patellofemoral syndrome and recentering of the patella in seven cases out of nine with severe patellofemoral osteoarthrosis.ConclusionDistal femoral varus osteotomy, with lateral opening wedge and fixation can be a good alternative to treatment of lateral tibiofemoral osteoarthritis associated with a valgus knee originating in the femur. The association of patellofemoral osteoarthritis does not affect the functional results.Level of evidenceLevel IV. Retrospective study.