To our knowledge, the comparison between the ultrasound-guided lumbar erector spinae plane block and the pericapsular nerve group block has not been investigated before in previous literature.

Inclusion Criteria:

• Both genders Type of surgery; unilateral elective total hip replacement. Physical status ASA I, II Age more than or equal 65 Years. Body mass index (BMI): > 20 kg/m2 and < 35 kg/m2.

Exclusion Criteria:

• Patient refusal. Patients with known sensitivity or contraindication to drugs used in the study (local anesthetics & opioids).

History of psychological disorders and/or chronic pain. Pre- existing peripheral neuropathies Coagulopathy. Infection of the skin at the site of needle puncture area.