In PENG block technique, the local anesthetic agent is injected between the psoas tendon and the pubic ramus to block the sensory branches of the nerves which innervates the hip capsule for providing analgesia without causing muscle weakness. Since the PENG block is a facial plane block, it causes a volume dependent distribution. There are a few case reposts and cadaveric studies on volume dependent effect of analgesia and motor weakness of PENG block.

In our study, we aimed to evaluate the clinical effects of the volume-dependent efficacy of PENG block.

Femur fracture is the one of the most common case groups and it is seen mostly in the elderly patient population with comorbidities. For these patients, perioperative, postoperative analgesia and early mobilization are important to reduce cardiopulmonary complications and morbidity. Femoral fracture operations are mostly performed under spinal anesthesia especially under unilateral spinal anesthesia to sustain more stable hemodynamics. The lateral decubitus position, which is used for unilateral spinal anesthesia, is a painful position for these patients. Intravenous opioids are used for this procedure, however they have possible side-effects, such as sedation, inhibition of respiratory, lower blood pressure. Because of these reasons, pericapsular nerve block (PENG) has been applied recently to avoid complications. By using PENG block , positioning for spinal anesthesia is easier for patients and anesthesiologists, and postoperative analgesia can be provided.

By PENG block, the local anesthetic agent is injected between the psoas tendon and the pubic ramus to block the sensory branches of the nerves innervating the hip capsule, thus providing analgesia in patients, but muscle weakness is not expected. Becacuse PENG block is a facial plane block, it shows a volume dependent distribution. There are a few case reposts and cadaveric studies, which are showing volume depend effect of analgesia and motor weakness of PENG block.

In our study, we aimed to evaluate the clinical effects of the volume-dependent efficacy of PENG block.

Inclusion Criteria:

• Patients who will undergoing hip arthroplasty surgery
• Patients over the age of 18
• ASA I-II-III patients
• Patients who will be operated under spinal anesthesia

Exclusion Criteria:

• ASA IV patients, Pregnant women
• Patients who are not suitable for spinal anesthesia
• Patients diagnosed with Alzheimer's and dementia who cannot cooperate
• Patients who are not suitable for peripheral nerve block (patients with infection in the injection area, with local anesthetic allergy, with coagulopathy)
• Patients who do not want to participate in the study
• Patients under the age of 18
• Patients switched to general anesthesia

Patients will be randomized using the closed envelope method. While the practitioner knows the interventions to be made, the data collector will collect the data without learning the patient's group.