A Prospective Randomized Controlled Trial Comparing Femoral Nerve Block and Combined Pericapsular Nerve Group (PENG) Plus Femoral Nerve Block for Perioperative Analgesia in Geriatric Hip Fracture Surgery

Hip fractures represent one of the most common orthopedic emergencies in the geriatric population and are associated with significant pain, morbidity, and mortality. Effective perioperative analgesia is essential in this fragile patient group, as inadequate pain control may contribute to delayed mobilization, increased cardiopulmonary complications, delirium, and prolonged hospital stay. Traditional opioid-based analgesic strategies are frequently associated with adverse effects such as nausea, vomiting, respiratory depression, and cognitive impairment, particularly in elderly patients. Therefore, regional anesthesia techniques have gained increasing importance in hip fracture surgery.

The hip joint has a complex sensory innervation primarily derived from the femoral, obturator, and accessory obturator nerves. The femoral nerve block is a well-established technique that provides effective analgesia for hip surgery; however, it may be associated with quadriceps muscle weakness due to motor fiber involvement, potentially delaying early mobilization. The pericapsular nerve group (PENG) block, first described in 2018, selectively targets the articular branches of the femoral, obturator, and accessory obturator nerves while largely preserving motor function. Emerging evidence suggests that the PENG block may provide effective analgesia with minimal impact on quadriceps strength.

Despite these findings, the additional analgesic benefit of combining the PENG block with the femoral nerve block remains unclear. This study is designed to evaluate whether the addition of the PENG block to a standard femoral nerve block improves perioperative analgesic outcomes in elderly patients undergoing hip surgery under spinal anesthesia.

This prospective, single-center, randomized controlled trial will be conducted at Ankara Bilkent City Hospital. A total of 68 patients aged 65 years or older, classified as American Society of Anesthesiologists (ASA) physical status I-III, and scheduled for hip surgery under spinal anesthesia will be enrolled after obtaining written informed consent. Patients will be randomly allocated into two groups: Group 1 will receive a preoperative femoral nerve block, and Group 2 will receive a combination of preoperative PENG block and femoral nerve block.

All nerve blocks will be performed approximately 30 minutes before surgery in the designated block area under standard monitoring, including electrocardiography, non-invasive blood pressure measurement, and pulse oximetry. Supplemental oxygen will be administered via nasal cannula at 2 L/min. The PENG block will be performed under ultrasound guidance using an 80-mm block needle, with 20 mL of 0.25% bupivacaine injected incrementally beneath the psoas tendon between the anterior inferior iliac spine and the iliopubic eminence. The femoral nerve block will be performed under ultrasound guidance using a 50-mm block needle, with 20 mL of 0.25% bupivacaine administered incrementally around the femoral nerve.