Patient suffer from moderate posterior knee pain after TKA despite injection of local anesthetic around the femoral or saphenous nerves. Indeed, the posterior part of the knee is innervated by the sciatic nerve. This nerve is not routinely blocked as clinicians fear to produce a motor block of the leg that might impair the postoperative assessment. An analgesic alternative is the infiltration of the knee with local anesthetics performed by the surgeon. Recently a trial(1) demonstrated that a selective tibial nerve block provides an effective analgesia without a motor blockage when compared with a sciatic nerve block. The objective of this randomized controlled double-blinded trial is to assess whether a tibial nerve block is more effective for the postoperative pain than local infiltration analgesia when there are combined with an adductor canal block, without decreasing the functional parameters.

Inclusion Criteria:

• Patient scheduled for a total knee arthroplasty under spinal block.
• Patient with a weight above 40kg.

Exclusion Criteria:

• Patient with ASA IV status.
• Contraindication to spinal block, or peripheral nerve blocks.
• Neurological deficit of the lower limb.
• Patient with renal dysfunction.
• Patient with chronic pain, opioid consumption or alcohol consumption.
• Pregnancy.