Venous thromboembolism is a major cause of morbidity and mortality after lower limb orthopaedic surgery in the adult patient. If, as suggested, DVT formation begins intra-operatively then targeting this period to prevent clot formation could substantially reduce DVT rates in the TKA population. The present study aims to determine whether this intra-operative regional heparinization technique is effective in preventing the intra-operative formation of DVT following TKA, as evidenced by venography in the early post-operative period.