Varus-Valgus Constrained Implants in Revision Total Knee Arthroplasty: Mean Clinical Follow-up of Six Years

Abstract Introduction There is scant literature evaluating varus-valgus constrained (VVC) prostheses in contemporary revision TKA. Therefore, we aimed to evaluate the durability of VVC revision TKA with selective use of cones. Methods A retrospective review of 194 revision TKAs with VVC was performed from 2005-2018 at a single institution. The final cohort consisted of 168 TKAs with a mean follow-up of six years. Stems were used in all but one TKA, tibial cones in 48%, and femoral cones in 19%. Anderson Orthopaedic Research Institute (AORI) classification in femurs was 1 in 57, 2A in 33, 2B in 62, 3 in 16, and in tibias, 1 in 42, 2A in 29, 2B in 81, and 3 in 16. Results Survival analysis showed 93% were free of revision for aseptic component loosening, 76% were free of revision for any reason, and 74% were free of reoperation at six years. AORI 3 femur or tibia, age Conclusions VVC revision TKA with selective use of cones provided a reasonable outcome as 93% were free of revision for aseptic loosening at six years. However, given the rate of patients with progressive radiographic changes and survivorship free of reoperation of 74% at six years, long-term follow-up will help assess the durability of these constructs.