Knee Arthroplasty in Severe Varus Advanced Knee Osteoarthritis with Proximal Tibia Malunion: a case report

Abstract

Alignment is crucial for successful knee arthroplasty.1 Tibia malunion will make arthroplasty more challenging. In this case, we present advanced knee osteoarthritis with tibia vara due to malunion that needs corrective osteotomy during knee arthroplasty. Case Presentation: A 70 years old female presented to our office complaining pain in both knees markedly on the left, profoundly felt during walking. She has a history of being hit by motorcycle 15 months ago and left knee was more bent since then. Physical examination of the left knee showed severe varus, mild effusion, tenderness on medial tibial condyle, otherwise normal. Plain radiographs showed advanced bilateral knee osteoarthritis with left proximal tibia malunion. Patient underwent left knee arthroplasty with corrective tibia and fibula osteotomy. Solutions and Outcome: Patient underwent closed wedge tibial osteotomy together with fibula osteotomy followed by knee arthroplasty with posterior-stabilized implant and tibial stem extension in a single surgery. Tibial osteotomy was reinforced using plate and screws. Partial weight bearing was achieved in second postoperative day and discharged on the third day. Patient able to walk with painless left knee after 1 month. Discussion: Severe deformity that causes huge malalignment makes knee arthroplasty difficult. Some methods are available to correct malalignment.1 In this case, the surgeon chose to do closed wedge tibial osteotomy reinforced with plate and screws to correct the proximal tibia malunion. Arthroplasty was done using posterior-stabilized implant and tibial stem extension. Patient shows good result in alignment and function. Conclusion: Correcting the associated deformity is crucial in achieving good alignment in knee arthroplasty. Even in our case of severe genu varus due to proximal tibia malunion, correcting proximal tibia varus deformity prior to knee arthroplasty shows good alignment and function. References: Mullaji AB, Padmanabhan V, Jindal G. Total Knee Arthroplasty for Profound Varus Deformity. 2005;20(5):550–61.