To evaluate the influence of posterior tibial slope on range ofmovements following a total knee Arthroplasty. To assess the functional outcome following a total knee Arthroplasty according to KneeSociety Score. Methods: In this study 30 patients with OA knee were studied. All the cases were treatedat department of orthopaedics at NMCH, Patna Study duration of Two years. The duration of follow up ranged from 3 weeks to 6 months. All the cases in this study were Primary OA knee. No post traumatic or pathologicalknees were taken into the study. Post operatively all patients will be subjected to x-ray imaging and evaluated clinically at 3 weeks, 3 months and 6 months for the range of movements and Knee Society Score.