Popliteal Sciatic nerve block is a regional technique that provides safe and reliable perioperative anesthesia and analgesia of lower leg and foot used in diabetic patients. Different additives have been used with local anaesthetics to achieve dense and prolonged block. Magnesium sulfate possesses analgesic properties owing to its effect on NMDA receptors.

Inclusion Criteria:

• (ASA) II or III
• scheduled for diabetic foot surgeries.

Exclusion Criteria:

• Patients who refused the anaesthetic technique,
• whose BMI ≥ 35 kg/ m2,
• unable to properly describe postoperative pain to investigator (dementia, delirium, psychiatric and neurological disorders),
• patients with coagulopathy, skin infection at the site of injection,
• preoperative use of opioid or non-steroidal anti-inflammatory drugs,
• allergy or contraindication to studied medication