Hypothesis: General anaesthesia compared to intrathecal anaesthesia will give shorter length of hospital stay (LOS) for patients undergoing total knee arthroplasty (TKA).~Primary endpoint: time from end of surgery until the patient meets the discharge criteria.~Secondary endpoints:~Will general anesthesia produce less post operative pain?~Is there any difference in post operative orthostatic function (dizziness) between the groups?~Time until the patient meets the discharge criteria from PACU~How many patients will need at least one urinary bladder catheterization?
Hypothesis: General anesthesia as compared to intrathecal (i.e. spinal anesthesia) anesthesia will result in shorter length of hospital stay for patients undergoing total knee arthroplasty.~Primary endpoint: time from end of surgery until the patient is street ready~Secondary endpoints: will general anesthesia produce less postoperative pain as compared to intrathecal anesthesia? Is there any difference in post operative dizziness between the groups.