A 46-year-old female patient with Ehlers-Danlos Syndrome had undergone fusion of her right knee 25 years before presentation. This markedly affected her quality of life. She underwent a two-stage conversion to a constrained rotating-hinge total knee arthroplasty. She regained a satisfying range of motion and she has a painfree, mobile and stable knee at 42 months follow-up. Conversion of knee fusion to TKA is a demanding procedure that should only be performed by experienced knee surgeons, in selected cases and on highly motivated patients. Complication and revision rates are reportedly very high but global satisfaction is surprisingly good. Ehlers-Danlos Syndrome was not shown to be a contraindication for such surgeries.