Clinical Trials

Inclusion Criteria:

1. Adult patients with an American Society of Anesthesiologists (ASA) physiological status I-III
2. Patients presenting for unilateral primary total knee replacement.
3. No focal neurologic deficit of the surgical lower extremity.
4. Cognitively intact with the ability to sign informed consent
5. Patients 18 years of age and older

Exclusion Criteria:

1. Chronic pain syndromes such as fibromyalgia or complex regional pain syndrome
2. History of long term use of daily opioids (>1 months) with OME >5mg/day.
3. Body mass index (BMI) > 40 kg/m2
4. Allergies to medications used in this study such as: fentanyl, hydromorphone, ketorolac, ibuprofen, acetaminophen, local anesthetics, oxycodone, OxyContin, tramadol, ondansetron, droperidol, or dexamethasone, celecoxib
5. Major systemic medical problems such as:
   • Severe renal disorder defined as glomerular filtration rate (GFR) <50 units/m2
   • Cardiovascular disorders defined as CHF NYHA class III-IV
   • Severe hepatic disorder defined as current or past diagnosis of acute/subacute necrosis liver, acute hepatic failure, chronic liver disease, cirrhosis (primary biliary cirrhosis), fatty liver, chronic hepatitis/toxic hepatitis, liver abscess, hepatic coma, hepatorenal syndrome, other disorders of liver.
6. Impaired cognitive function or inability to understand the study protocol
7. Contraindication to a regional anesthesia technique (e.g., preexisting neuropathy in the operative extremity, coagulopathy [platelets < 100,000, INR >1.5], refusal, etc.).
8. Previous contralateral knee replacement managed with regional or periarticular injection
9. Unable to follow-up at the 3 month interval at Mayo Clinic in Rochester, MN
10. Pregnancy or breast feeding (women of child-bearing potential, must have a negative pregnancy test)