Same-stage total knee arthroplasty and osteotomy for osteoarthritis with extra-articular deformity. Part I: Tibial osteotomy, prospective study of 26 cases

Abstract

BackgroundIn patients with advanced knee osteoarthritis and extra-articular knee deformity (EKD), ligament balance may be difficult to achieve during total knee arthroplasty (TKA). Treatment options include two-stage surgery with the first stage involving correction of the EKD and same-stage TKA and tibial osteotomy (1S-TKA-TO). The objective of this study was to assess outcomes in 26 patients managed with 1S-TKA-TO. Hypothesis1S-TKA-TO produces satisfactory clinical and anatomical outcomes and is not associated with higher morbidity rates compared to TKA alone or two-stage TKA-TO. Material and methodsA prospective study was conducted in 25 patients (26 knees) managed with 1S-TKA-TO between 1995 and 2014. There were 16 males and 9 females with a mean age of 64 years (range, 29–80 years) and a mean body mass index of 29.6 (range, 24–49). The EKD was constitutional in 14 knees, post-traumatic in 5 knees, and induced by TO in 7 knees. None of the patients received a hinged knee implant. In each patient, the clinical International Knee Society (IKS score) was assessed and the hip-knee-ankle angle (HKA), tibial mechanical angle (TMA), and femoral mechanical angle (FMA) were measured on radiographs before surgery and at last follow-up. ResultsThe mean IKS score increased significantly, from 70 before surgery to 170 at the end of the mean 9-year follow-up. Mean flexion range increased from 98° to 107°. The clinical and anatomical outcomes were satisfactory in 25 patients. In the remaining patient, who had a history of multiple surgeries for Blount disease and a body mass index of 49, a severe complication consisting in massive skin necrosis followed by infection occurred; this was the only patient who required revision surgery with implant removal. DiscussionThese findings are consistent with the satisfactory outcomes observed in earlier studies, most of which included small numbers of patients. The alternatives to 1S-TKA-TO are under evaluation. The best indication for 1S-TKA-TO may be knee osteoarthritis with a greater than 10° intra-osseous deformity. Level of evidenceIV, prospective observational cohort study.