Inclusion Criteria:  All consecutive patients age 18 years or older, with a diagnosis of primary osteoarthritis of the hip or knee, who underwent elective, primary, unilateral TKA or THA.  Exclusion Criteria:  previous TKA or THA within 3 months Revision surgery Surgical procedures related to a previous complication ASA PS IV recent history (6 months) of unstable acute coronary syndrome or decompensated heart failure