Background: Popliteal block is a widely used technique to provide anesthesia or analgesia for below-knee surgical procedures. In this study, the investigators compare ultrasound-guided popliteal blocks via posterior, lateral, and medial approaches to find out the approach with the best outcome.

Methods: In this randomized, controlled clinical trial, one hundred and twenty ASA physical status of class I and II patients undergoing below-knee surgery were involved. These patients were divided into three equal groups at randomly based on the route assigned for the US-guided popliteal block: the posterior, lateral, and medial approach groups. In this study, technical characteristics [number of attempts to get the proper injection site and block performance time], anesthetic and analgesic characteristics [success rate, block onset, potency, and duration, time to ask, and the consumed amount of postoperative analgesia], discomfort rate in respect to position and needle insertion and the associated complications were recorded.

Inclusion Criteria: This study included

• ASA physical status (PS) class I and II
• weighing 70-85 kg,
• undergoing elective below knee surgeries

Exclusion Criteria:

• patients who refused to participate in the study
• those having an allergy to local anesthetics
• peripheral neuropathy, coagulopathy
• diabetes mellitus
• severe hepatic
• renal impairment
• infection, mass and crush injury or open wound at the nerve block site
• patients receiving chronic analgesic therapy.