Prolonged Popliteal Fossa Nerve Blockade (Prolonged Pop)

Following major foot and ankle surgery patients complain of severe pain. Currently, Hospital for Special Surgery (HSS) usually uses nerve blocks (injections of local anesthetic near nerves supplying the lower leg) to help manage pain after this type of surgery. Patients also receive additional pain pills, including narcotics as needed. This study looks at addition of medications to the local anesthetic for the nerve blockade. The investigators hope that these medications (dexamethasone and buprenorphine) will prolong the pain relief from the nerve block. There are 3 groups in the study. One group is a control, and receives usual therapy: nerve block + pain pills. This is typically what the patient would receive as standard care if they were not in the study. One group uses a nerve block with additives (+ pain pills). One group gets a nerve block (local anesthetic only) + pain pills + intravenous buprenorphine - this is meant to see if the buprenorphine acts directly on the nerve that was blocked, or indirectly acts on the brain.

Patients will be followed while in the hospital, and contacted by telephone and/or email after discharge for 2-3 days. Patients will be asked about their pain levels and the duration of their block. The investigators will enroll 90 patients.

Inclusion criteria

• Patients of Dr. Levine or Dr. Roberts at Hospital for Special Surgery
• Patients aged 18-75
• Patients scheduled for discharge from HSS after foot or ankle surgery
• A single-injection popliteal fossa nerve block is judged appropriate
• Surgery confined to foot and ankle (no iliac crest bone graft planned - iliac aspirate is not an exclusion criterion)

Exclusion criteria

• < 18 and > 75
• Surgery that will cause pain at sites outside the distal lower extremity (e.g. iliac crest bone graft)
• Bilateral surgery
• Chronic pain (defined as regular use of opioid analgesics for > 3 months)
• Chronic use of steroids (defined as regular use of steroids for > 3 months)
• Contraindication to performance of the popliteal fossa nerve block with 30 cc 0.25% bupivacaine (e.g. alleged bupivacaine sensitivity, low body weight, etc.)
• Contraindications to dexamethasone or buprenorphine (e.g. allergy, insulin dependent diabetes mellitus, etc.)
• Patients who have been diagnosed with altered pain perception or have lack of sensation
• Inability of the patient to describe postoperative pain (e.g. psychiatric disorder, dementia)
• Non-English speaking patients (the questionnaire is in English, and translations would have to be separately validated)