Modified TIPS Block for Total Knee Arthroplasty

All blocks will be performed after induction of general anaesthesia (GA). Upon arrival to the operating room (OR), a multichannel monitor will be attached to patients, followed by the administration of 2 mg midazolam IV after securing an IV cannula. Controlled GA via a laryngeal mask airway (LMA) will be done to all patients

Patients will receive distal FTB through conventional lateral to medial approach, in addition to a supra-sartorial plane injection. Distal adductor canal block via another needle puncture.Ten mL of a mixture of 0.25 % bupivacaine and 8 mg dexamethasone will be injected in the suprasartorial plane and 20 mL will be injected at the distal adductor canal.Ten mL of the LA mixture will be injected 2 cm above the FT apex via ultrasound guided in-plane lateral to medial approach just lateral to the superficial femoral artery

Patients will receive ultrasound guided single puncture triple injections through medial to lateral approach. LA will be injected at the distal FT lateral to the superficial femoral artery (FA), deep to adductor longus muscle (ALM), and at the supra-sartorial plane.Both groups will receive a mixture of 0.25 % bupivacaine and 8 mg dexamethasone. Ten mL will be injected in the suprasartorial plane and 20 mL will be injected at the distal adductor canal.Ten mL of the LA anaesthetic mixture will be injected 2 cm above the FT apex via ultrasound guided in-plane medial to lateral approach just lateral to the superficial femoral artery. Then, the needle will be redirected just underneath the ALM and 10 mL of the LA mixture will be injected in the plane between the ALM and the adductor magnus muscle (AMM).Total volume of LA will be 50 mL.

Postoperatively, multimodal analgesia regimen will be continued in the form of paracetamol 1 g /8 hours and ketorolac 30 mg /8 hours intravenously for 24 hours. Intravenous morphine patient controlled analgesia will be started at the end of surgery at a concentration of 0.5 mg/ml without a background infusion on a demand dose of 1 mg with a lockout interval of 10 minutes