Comparison between efficacy of local infiltration analgesia versus adductor canal block using 0.25 percent levobupivacaine and morphine for post-operative analgesia in total knee arthroplasty.

INTERVENTION: Intervention1: Adductor Canal Block: Under strict aseptic precautions and standard ASA monitoring, ultrasound guided adductor canal block will be performed in patients posted for unilateral total knee replacement surgery. With the patient in supine position and the operative limb slightly externally rotated, a high frequency linear ultrasound probe will be placed transversely at the mid thigh level to identify the adductor canal beneath the sartorius muscle. The femoral artery will be identified as the primary landmark within the canal. Using an in plane lateral to medial approach a 22G echogenic block needle will be advanced under real time ultrasound guidance until the needle tip is positioned adjacent to the femoral artery beneath the sartorius muscle. After careful negative aspiration, 1 to 2 mL normal saline will be injected for confirmation of proper needle placement by hydro dissection, followed by administration of 20 mL of 0.25 percent levobupivacaine and 10 mg morphine incrementally with repeated aspiration. Adequate spread of local anesthetic within the adductor canal around the femoral artery will be visualized sonographically. Patients will subsequently be monitored for analgesic efficacy, quadriceps muscle strength, hemodynamic stability, and any block related complications. Intervention2: local infiltration analgesia: Under strict aseptic precautions, local infiltration analgesia will be administered by the operating surgeon at the end of total knee replacement surgery prior to wound closure. The study solution consisting of morphine 10 mg combined with 20 mL of 0.25 percent levobupivacaine diluted with normal saline to a total volume of 40 mL will be prepared under sterile conditions. The solution will be infiltrated systematically into the periarticular and intra articular tissues including the posterior capsule, medial and lateral retinaculum, collateral ligaments, quadriceps tendon, patellar tendon, synovium, and surrounding soft tissues while avoiding intravascular injection. Aspiration will be performed intermittently during infiltration to prevent accidental vascular administration. The infiltration technique and total drug volume will be standardized for all patients. Following completion of infiltration and wound closure, patients will be monitored postoperatively for analgesic efficacy using VAS scores, time to first rescue analgesic requirement, total opioid consumption, quadriceps strength, hemodynamic stability, and any adverse effects such as nausea, vomiting, pruritus, local anesthetic toxicity, or wound related complications. Control Intervention1: local infiltration analgesia: Under strict aseptic precautions, local infiltration analgesia will be administered by the operating surgeon at the end of total knee replacement surgery prior to wound closure. The study solution consisting of morphine 10 mg combined with 20 mL of 0.25 percent levobupivacaine diluted with normal saline to a total volume of 40 mL will be prepared under sterile conditions. The solution will be infiltrated systematically into the periarticula CONDITION: Health Condition 1: O‐ Medical and Surgical Health Condition 2: M171‐ Unilateral primary osteoarthritisof knee PRIMARY OUTCOME: To compare postoperative pain scores during rest and during movement at six hours after total knee replacement surgery.Timepoint: 6 hours INCLUSION CRITERIA: ASA Physical Status 1 to 3 SECONDARY OUTCOME: 1.To compare post‐operative static & dynamic VAS scores at 12 & 24 hours. ; 2.To compare time to first rescue analgesic requirement. ; 3. To compare total tramadol consumption in first 24 hours. ; 4. To compare quadriceps muscle strength. ; 5. To compare incidence of postoperative adverse effects such as nausea, vomiting, pruritus, sedation, urinary retention. ; 6. To compare patient satisfaction using Likert scale. ; Timepoint: 12 hour & 24 hour