The evaluation of the outcome of CCK prostheses in primary TKA Between 2002 and 2008 we implanted 34 CCK knees in 31 patients. Mean age was 69 (58–79) 10 patients were operated because of valgus knee and lateral compartment arthritis, 8 because of post-traumatic ligamentous laxity and/or bone loss and the remaining patients presented with advanced OA and varus deformity exceeding 30 degrees. All patients were followed regularly with radiographs annually and there were assessed clinically with KSS and Womac score. The findings were compared with a group of patients with similar characteristics and a CR prosthesis. Mean follow-up was 3 years (6–1) There was no revision in this group neither was any radiological abnormality. Clinical outcome in terms of KSS and WOMAC score was excellent and comparable to the CR group. The main indication for a CCK prosthesis is the ligamentous insufficiency. There is enough evidence to support its superiority as a treatment option in valgus knees but long term performance is yet unclear. CCK prostheses are a reliable solution for unstable or imbalanced knees their long term behaviour though, is yet unclear