levobupivacaine

The peri-articular infiltration of multimodal agents will consist of 150 mg of levobupivacaine, 10 mg morphine and 30mg ketorolac diluted in 0.9% saline to make a volume 100 ml. (0.5ml 1:1000 adrenaline will be added to the mixture to reduce blood loss after the operation) Fifty ml of the mixture will be injected into the posterior, medial and lateral soft-tissues just prior to implantation of the TKA components. Care will be taken to avoid excessive infiltration in the area of the common peroneal nerve. Then, while the cement is curing, the anterior soft-tissues including the quadriceps mechanism, the retinacular tissues and the subcuticular tissues will be infiltrated with the remaining 50 ml of peri-articular injection.

Under aseptic conditions, the femoral artery will be palpated immediately below the inguinal ligament and nerve stimulation will be used to identify the femoral nerve just lateral to the artery. Once the femoral nerve has been identified the block may be performed in the routine manner, using 30 ml of levobupivacaine 0.25%. The precise technique used will be noted on trial documentation.

A validated, patient-reported 100 mm visual analogue pain score. It is a line 100mm long on which patient places a line through to mark the severity of the pain the patient is experiencing from 0mm= No pain to 100mm wost pain possible.

An ordinal 4-point pain score recorded every six hours by an independent nurse during the first 48 hrs after the surgery.

The total use of "as required" analgesia in the first 48hrs after the operation