Both perineural and systemic dexamethasone administration allows an increase in analgesic duration of regional anesthesia.

There is a lack of data to determine wich route allows a longer analgesic effect.

This study aims to determine wether perineural dexamethasone allows a longer analgesic duration than systemic route in combination with regional anesthesia (Ropivacaine 0.375%) for front foot surgery.

This is a prospective, randomized, double-blind controlled trial.

All Patients undergoing front foot surgery with metacarpal osteotomy will be screened for inclusion in the protocol. All patients without exclusion criteria will be included in the study.

All patients will receive 30cc mixure of Ropivacaine 0,375% in perineural injection and surgery will be performed under regional anesthesia only. If needed, a sedation with midazolam (1mg) will be performed.

The patients will be randomized over 2 groups:

• "Perineural group":

  • 1cc (4mg) of dexamethasone will be administrated in perineural injection
  • 2.5cc of isotonic saline solution will be administrated in systemic injection

• "Systemic group":

  • 1cc of isotonic saline will be administrated in perineural injection
  • 2.5cc (10mg) of dexamethasone will be administrated in systemic injection

For both groups perineural injection will be performed at the ankle and the following nerves will be targeted: the tibial nerve, saphenous nerve, the deep fibular nerve, the superficial fibular nerve and the sural nerve.

Post-operative analgesia will be reached with paracetamol (1gr each 6 hours) and Ketoprofen (100mg each 12 hours).

After surgery, patients will be asked to write down the time to the first opioids request during the first 48 hours, maximal pain during the first 48H using a visual analog scale, occurrence of nausea or vomiting, overall satisfaction regarding pain relief management and any significant side effects during the first 7 days.

The primary objective of the study is to determine if perineural dexamethasone is associated with a longer analgesic duration than systemic route in combination with regional anesthesia (Ropivacaine 0.375%) for front foot surgery.

The primary end-point will be time to the first opioids request during the first 48 hours.

Inclusion Criteria:

• front foot surgery with metacarpal osteotomy under regional anesthesia
• >18 years old
• consent to participate in the study

Exclusion Criteria:

• refusal to participate
• pregnancy
• feeding
• pre existing neuropathy
• ropivacaine allergy
• paracetamol allergy
• liver failure
• cardiac failure
• ketoprofen allergy
• gastric ulcer within the previous year
• tramadol allergy
• history of epilepsy