Pericapsular Nerve Group (PENG) Block Versus Periarticular Injection for Pain Management After Total Hip Arthroplasty

A curvilinear 2-5MHz ultrasound probe will be initially placed in a transverse plane over the anterior superior iliac spine and then aligned with the pubic ramus by rotating the probe counterclockwise approximately 45 degrees. In this view, the iliopubic eminence, the iliopsoas muscle and tendon, the femoral artery, and pectineus muscle will be observed. A 22-gauge, 80-mm needle will be inserted from lateral to medial in an in-plane approach to place the tip in the musculofascial plane between the psoas tendon anteriorly and the pubic ramus posteriorly. A total volume of 20 ml of ropivacaine 0.3% will be injected.

The periarticular injection solution contained 20mL of 7.5 mg/mL ropivacaine, 30mg of ketorolac, and 0.3mL of 1.0 mg/mL epinephrine. These agents were mixed with normal saline to a combined volume of 50mL. The surgeon injected this mixture into the tensor fascia lata, subcutaneous tissues, abductors, short external rotators muscles, and structures in the capsule.