Mepivacaine vs Bupivacaine Spinal Anesthesia for TKA

Patients will be administered a standard dose of mepivacaine 1.5% (4.5ml, 67.5mg) for total knee arthroplasty prior to surgery

Patients will be administered a standard dose of 0.75% hyperbaric bupivacaine (1.4ml, 10.5mg) for total knee arthroplasty prior to surgery