Mepivacaine vs Bupivacaine Spinal Anesthesia for TKA
This study is a prospective, double-blind prospective randomized controlled trial comparing mepivacaine and bupivacaine spinal anesthesia for same-day discharge readiness following a unilateral primary elective TKA procedure.

Study data will be collected during the patient's hospital stay for their TKA procedure, and the primary outcome of same-day discharge readiness will be assessed the day of surgery. Patients will also be contacted at Day 3 post-op to assess for any complications, current level of pain, and pain medication utilization.
- EligibilityCriteria: Inclusion Criteria:  Patient is at least 18 years of age who are scheduled for a primary elective TKA. Patient can ambulate at least 10 feet independently without human assistance. Patient must be a candidate for same day discharge as determined by American Society of Anesthesiologists (ASA) Physical Status Classification I and II  Exclusion Criteria:  Patients scheduled for bilateral TKAs Contraindication to spinal anesthesia Revision TKAs Allergy or contraindication to NSAIDs (e.g. chronic anti-coagulant use) Workers' Compensation patient Type I Diabetes Type II Diabetes requiring insulin medication. Pre-operative narcotics use with the exception of tramadol. Renal insufficiency (GFR < 60) that may impact post-operative protocol Cognitive deficiencies that prevent the patient from providing their own informed consent Language barrier preventing completion of study forms in English - HealthyVolunteers: No - Gender: All - MinimumAge: 18 Years - StdAgeList: Adult, Older Adult