PENG Block Versus LP Block for THA Postop Pain

Phase 4

Completed

Interventions: Drug: Peri-capsular Nerve Group (PENG)
Other: Lumbar Plexus Block (LPB)

Brief Summary: The purpose of this randomized, double blinded, prospective study is to compare the postoperative analgesia provided by the PENG block to that provided by the LPB for patients undergoing primary anterior approach THA.

Detailed Description: Regional anesthesia procedures represent a common modality for postoperative analgesia after total hip arthroplasty surgeries (THA). The standard practice many years has been the Lumbar Plexus block (LPB), which anesthetizes the L1-L5 lumbar nerve roots1. While the LPB offers analgesia from the associated sensory block, it also blocks motor fibers, leading to lower extremity weakness that could potentially delay the patient's ability to participate in early physical therapy and may thereby delay discharge. In the past several years, newer regional anesthesia block approaches have been described and investigated in an attempt to provide patients with postoperative analgesia while avoiding associated muscle weakness, facilitating earlier physical therapy participation and discharge. One such nerve block is the peri-capsular nerve group (PENG) block, which anesthetizes the articular branches of the femoral, obturator, and accessory obturator nerves providing sensory innervation to the hip joint capsule without consistently causing lower extremity weakness2. Some institutions are utilizing the PENG block to provide postoperative analgesia and facilitate early mobilization. There are currently no prospective studies that directly compare the efficacy of LPB to PENG block for providing postoperative analgesia after THA.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

contraindications to regional anesthesia, such as an allergy to amide local anesthetics
pre-existing coagulopathy or thrombocytopenia <100,000
refusal of analgesic block for pain management
presence of an progressive lower extremity neurological deficit
localized or systemic infection
chronic use of high dose opioid analgesics (defined as daily use greater than 60 mg oxycodone equivalents)
pregnant
refusal of consent

Arm && Interventions

Group	Intervention	Description
Peri-capsular Nerve Group (PENG)	Peri-capsular Nerve Group (PENG)	Those subjects assigned to the PENG treatment arm will receive a PENG block using 20mL of 0.2% ropivacaine with 1:400,000 epinephrine dosed in 5mL increments with negative aspiration beforehand and between each aliquot.
Lumbar Plexus Block (LPB)	Lumbar Plexus Block (LPB)	Those subjects assigned to the LPB treatment arm will receive a stimulation-based LPB dosed with 20cc of 0.2% ropivacaine with 1:400,000 dilution epinephrine dosed in 5mL increments with negative aspiration beforehand and between each aliquot.

Primary Outcome Measures

Name	Time	Method
Numeric Rating Scale (NRS) Pain Score	hour 6	a comparison of patient-reported numeric rating scale (NRS) pain scores with movement at six hours following block placement. Equivalency will be defined as a difference of less than one point in either direction on the eleven-point NRS pain scale. Score ranges from 0-10 with a higher score denoting more pain.

Secondary Outcome Measures

Name	Time	Method
NRS Pain Score	hour 24	a comparison of patient-reported numeric rating scale (NRS) pain scores with movement at 24 hours following block placement. Score ranges from 0-10 with a higher score denoting more pain.
Time in Minutes Until Opioid Administration	hour 24	Time to first dose of opioid rescue for postoperative pain management - This outcome was evaluated in time to first opioid dose, which was measured in hours - no analysis for mean, median, or any of the others suggested - It was calculated as time of block to time of first opioid dose-hours and minutes.
Motor Strength	hour 6	straight leg raise at 6 hours after block placed rated on a 0-5 scale with a higher score indicating better movement
Distance Ambulated	hour 24	Recorded in feet during first physical therapy