PENG Block Versus LP Block for THA Postop Pain

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.

Inclusion criteria

• elective primary total hip arthroplasty surgery anterior approach
• provided informed consent
• no contraindications to medications used in providing the analgesic blocks

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