Pericapsular Nerve Group Block Versus Femoral Nerve Block Study

Hip fractures are among the most common injuries in older adults and are associated with substantial morbidity, mortality, and healthcare utilization. Spinal anesthesia is frequently used for surgical repair of proximal femur fractures because of its favorable safety profile in elderly patients. However, severe pain caused by the fracture often makes positioning for spinal anesthesia difficult, resulting in patient discomfort, prolonged procedure time, multiple needle insertion attempts, and increased procedural complexity.

Peripheral nerve blocks are increasingly used before spinal anesthesia to improve analgesia and facilitate patient positioning. The femoral nerve block (FNB) has long been established as an effective regional anesthesia technique for patients with hip fractures. More recently, the ultrasound-guided Pericapsular Nerve Group (PENG) block has been introduced as a motor-sparing technique targeting the articular branches of the femoral, obturator, and accessory obturator nerves that innervate the anterior hip capsule. Previous studies have demonstrated that the PENG block provides effective analgesia during positioning for spinal anesthesia and may offer superior pain relief compared with conventional techniques. However, evidence comparing the effects of PENG block and femoral nerve block on the technical performance of spinal anesthesia and perioperative hemodynamic stability remains limited.

This prospective, randomized controlled trial is designed to compare ultrasound-guided PENG block with ultrasound-guided femoral nerve block in patients undergoing surgery for proximal femur fracture under spinal anesthesia. The study will evaluate whether PENG block improves procedural conditions for spinal anesthesia compared with femoral nerve block while also assessing perioperative analgesia and hemodynamic responses.

The study hypothesis is that preoperative PENG block will provide better procedural conditions for spinal anesthesia than femoral nerve block by improving patient positioning, reducing pain during positioning, facilitating spinal needle placement, decreasing the need for supplemental analgesic or sedative medication, and contributing to greater perioperative hemodynamic stability.

Inclusion criteria

• Adults aged 50 years or older.
• Diagnosis of proximal femoral fracture.
• Scheduled to undergo surgical repair under spinal anesthesia.
• American Society of Anesthesiologists (ASA) physical status I-III.
• Able to provide written informed consent.

Exclusion criteria

• Refusal to participate or inability to provide informed consent.
• Coagulopathy or contraindication to spinal anesthesia or peripheral nerve block.
• Local infection at the planned injection site.
• Known allergy or hypersensitivity to local anesthetics.
• Pre-existing neurological disease affecting lower extremity function or sensory assessment.
• Cognitive impairment preventing reliable study participation or outcome assessment.
• Previous lumbar spine surgery.
• Polytrauma.
• Body mass index (BMI) <18 kg/m² or >40 kg/m².
• Current anticoagulant therapy that precludes neuraxial anesthesia or peripheral nerve block according to institutional practice.