Total Hip Arthroplasty (THA) Lumbar Plexus Verses Periarticular

Prospective, Randomized Controlled Trial Comparing Continuous Posterior Lumbar Plexus Nerve Block vs Periarticular Injection With Ropivacaine or Liposomal Bupivacaine (Exparel®) on Patients Undergoing Total Hip Arthroplasty

Total hip arthroplasty is a one of the most commonly performed surgical procedures with increasing numbers anticipated over the next several decades. The purpose of this study was to find a better way to make patients comfortable after their hip surgery. Three different ways of providing pain relief were compared, a peripheral nerve block in the lower back outside of the spinal space (using bupivacaine, a numbing medicine), or injections around the hip joint with one of two different medicines, either Ropivacaine or Liposomal Bupivacaine (Exparel®).

Total hip arthroplasty is associated with moderate to severe postoperative pain and an ideal clinical pathway for pain management has yet to be established. Multimodal pain management incorporating the use of regional anesthesia for THA has led to decreased hospital length of stay, improved patient comfort, and enhanced patient satisfaction that is efficacious and cost-effective. This investigation compared multimodal total joint arthroplasty pathways with continuous lumbar plexus blockade versus two different periarticular injection mixtures to potentially determine an ideal perioperative analgesia pathway for THA.

Patients undergoing elective, unilateral primary total hip arthroplasty within a clinical pathway utilizing preemptive low-dose opioid and non-opioid medications for multimodal analgesia were randomized to one of three different intervention groups after informed consent was obtained: posterior lumbar plexus block (PNB), periarticular infiltration (PAI) with ropivacaine, ketorolac, and epinephrine, and PAI with liposomal bupivacaine, ketorolac, and epinephrine. The investigators hypothesized differences in the analgesia outcomes between the three intervention groups would provide for an evidenced-based clinical pathway to emerge as a result of this study.

Inclusion Criteria:

1. Adult patients with an American Society of Anesthesiologists (ASA) physiological status I-III
2. Patients presenting for unilateral primary total hip arthroplasty
3. 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 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, tramadol, ondansetron, droperidol, dexamethasone, celecoxib and OxyContin

5. Major systemic medical problems such as:

   1. severe renal disorder defined as glomerular filtration rate (GFR) <50 units/m2
   2. cardiovascular disorders defined as Congestive Heart Failure (CHF) New York Heart Association (NYHA) class III-IV
   3. severe hepatic disorder defined as current or past diagnosis of acute/subacute necrosis of 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 hip 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 breastfeeding (women of child-bearing potential will require a negative pregnancy test)