Flex Appeal: Evaluating the Efficacy of Anesthetic Techniques for Manipulation of Knees Under Anesthesia

Inclusion: 1. Patients ≥18 years presenting for a manipulation of knee joint under anesthesia. 2. ASA Classification I - III. 3. English speaking patients. Exclusion: 1. ASA 4 or 5 2. Daily chronic opioid use (over 3 months of continuous opioid use). 3. Inability to communicate pain scores or need for analgesia. 4. Infection at the site of block placement 5. Age under 18 years old or greater than 75 years old 6. Pregnant women (as determined by point-of-care serum bHCG) 7. Intolerance/allergy to local anesthetics 8. Weight \<50 kg 9. Suspected, or known addiction to or abuse of illicit drug(s), prescription medicine(s), or alcohol within the past 2 years. 10. Uncontrolled anxiety, schizophrenia, or other psychiatric disorder that, in the opinion of the investigator, may interfere with study assessments or compliance. 11. Current or historical evidence of any clinically significant disease or condition that, in the opinion of the investigator, may increase the risk of surgery or complicate the subject's postoperative course. 12. BMI \>50 kg/m2. 13. Allergy or contraindication to local anesthetics or any component of the multimodal analgesic regimen (NSAIDs and acetaminophen) 14. Contraindication to spinal injection