Inclusion Criteria:  Age: 18-70 years. BMI: 20-30 kg.m2 Sex: both males and females. ASA physical status: I-III. Operation: knee arthroscopy.  Exclusion Criteria:  Patient's refusal to participate in the study. Aged less than 18 years, known allergy to L.A., Coagulopathy or thrombocytopenia, height less than 150 cm, morbidly obese infection at the site of injection. Chronic pain syndromes, pregnant woman Patients on regular use of analgesic or who received analgesic 24 h before surgery.