Peripheral Nerve Blocks vs Periarticular Local Anesthetic Injection for Total Knee Arthroplasty (TKA)

Prospective, Randomized, Controlled Trial Comparing Continuous Femoral and Single Injection Sciatic Peripheral Nerve Blocks vs Periarticular Injection With Ropivacaine or Liposomal Bupivacaine (Exparel) on Patients Undergoing Total Knee Arthroplasty

The purpose of this study is to find a better way to make patients comfortable after their knee surgery. The investigators compared three ways of providing pain relief, either by use of a nerve block at the femoral and sciatic nerve areas, or with actual injections in the surgical joint area with one of two different medicines, either ropivacaine or liposomal bupivacaine (Exparel®). The hypothesis was that the nerve block at the femoral and sciatic nerve areas would result in lower pain scores and opioid consumption than either of the two injections in the surgical joint area.

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

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 oral morphine equivalent (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 congestive heart failure (CHF) New York Heart Association (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, International Normalized Ratio (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, Minnesota

10. Pregnancy or breast feeding (women of child-bearing potential, must have a negative pregnancy test)