Early rehabilitation after anterior cruciate ligament reconstruction is of paramount importance and requires optimal pain control based on a multimodal concept, including injection of local anaesthetics. Regarding this latter, different options have emerged recently such as the adductor canal block, performed before the surgery by the anaesthesiologist or the infiltration of the articulation performed by the surgeon at the of the intervention. No trial has compared these two approaches. As practice of medicine should be based on evidence, we decided to undertake this randomised controlled trial where we compared the adductor canal block with the local infiltration analgesia technique in terms of pain and functional outcomes

Patients scheduled to undergo anterior cruciate ligament reconstruction under general anaesthesia will be randomly allocated to two groups: local infiltration analgesia or adductor canal block.

The local infiltration analgesia will be performed by the surgeon at the end of surgery with 20 mLs of ropivacaine 0.5%. The adductor canal block will be performed by the anaesthesiologist under ultrasound guidance after the surgery, before awaking the patient, using the same solution (20 mLs ropivacaine 0.5%)

Postoperative analgesia will include intravenous patient-controlled analgesia of morphine (settings 1 mg/ml, 2 ml/10 minutes, 40 mg/4 hours), ibuprofen (3x400 mg) and acetaminophen (4x1000 mg).

A research assistant and a physiotherapist, both blinded to the group allocation, will collect pain and rehabilitation data, respectively.

Inclusion Criteria:

• patients from 18 to 50 years old scheduled to undergo anterior cruciate ligament reconstruction

Exclusion Criteria:

• peripheral neuropathy
• pre-existing femoral neuropathy
• diabetes mellitus
• alcoholism
• drug addiction
• cancer with chemotherapy
• chronic pain state