This is a prospective randomized double blind controlled study to evaluate the post-operative analgesic effect of adductor canal block (ACB) or peri-articular injection (PAIs) compared to combined adductor canal block and infiltration of the interspace between popliteal artery and the capsule of posterior knee block ( IPACK) in patient undergoing total knee arthroplasty

This prospective randomized study will be carried out in Tanta University Hospitals in Anesthesia Department for one year after approval from ethical committee of faculty of medicine of Tanta university. After approval from institutional ethics committee, an informed consent will be taken from each patient. All data of the patients will be confidential with secret codes and private file for each patient, all given data will be used for the current medical research only. Any unexpected risks encountered during the course of the research will be cleared to the participants as well as to the Ethical Committee on time. Every patient will receive an explanation to the purpose of the study and every patient will have a secret code number to ensure privacy to participants and confidentiality of data.

Inclusion criteria:

Adult patients with severe osteoarthritis , ASA class I, II and III and scheduled for elective Total knee arthroplasty will be enrolled in the study.

Exclusion criteria:

• Patient who refuse the regional anesthesia technique.
• History of allergy to local anesthetics.
• Local infection at the site of the block.
• Patients with bleeding and coagulation disorders.
• Patient with Advanced renal, hepatic and cardiac diseases.
• Preexisting lower extremity neurological abnormality, or neuropathy and difficulties in comprehending (NRS).

Grouping and Allocation:

60 patients will be enrolled in this study in each group, Patients will be randomly classified into three equal groups (20 patients each).

Randomization will be done by computer generated numbers into:

Group (I): 20 patients will receive adductor canal block alone. Group (II): 20 Patients will receive peri-articular injection alone. Group (III): 20 patients will receive adductor canal block (ACB) and infiltration of the interspace between popliteal artery and the capsule of posterior knee block (IPACK).

Anesthetic technique:

Preoperative assessment will be done by:

History talking, clinical examination, routine laboratory investigations including CBC, coagulation profile, random blood sugar, liver and renal function tests. During the pre-anesthetic assessment, all patients will be familiarized with Numeric Rating Scale (NRS) score. On entering the operating room, intravenous line (IV) will be inserted, routine monitoring of heart rate by ECG, noninvasive blood pressure (NIBP), pulse oximetry will be done. All patients will receive spinal anesthesia with 3 ml 0.5% (15 mg) hyperbaric bupivacaine plus 25 μgm fentanyl at the L3/4 interspaces and the study of regional anesthetic technique will be performed postoperatively according to each group. All patients will receive postoperative analgesic regimen which is paracetamol 1gm intravenously every 8 hours and ketorolac 30mg every12 hours. Rescue analgesia in the form of 0.05 mg/kg of morphine IV will be administrated when the Numeric Rating Score (NRS) exceeding 3. The morphine dose will be repeated whenever indicated considering the total dose in the first 24 hours never exceeding 20 mg.

Measurements:

1. Demographic data (age, gender, weight, ASA classification).
2. Post-operative pain will be assessed by Numeric Rating Scale (NRS) from 0 to 10 at 0,2,4,6 then every 6h for 24 hours and in the second and third postoperative days at rest and during Physiotherapy.
3. Postoperative analgesia, which will be assessed by total analgesic consumption, and time till administration of first rescue analgesia will be recorded.
4. Effect on Motor function: by recording the mean time taken to achieve 90o active knee flexion each day till the third postoperative day.
5. Adverse effects: hypotension, Bradycardia, infection, hematoma and local anesthetic toxicity will be observed and treated accordingly.

Inclusion Criteria:

• Adult patients with severe osteoarthritis , ASA class I, II and III and scheduled for elective Total knee arthroplasty

Exclusion Criteria:

• Patient who refuse the regional anesthesia technique.
• History of allergy to local anesthetics.
• Local infection at the site of the block.
• Patients with bleeding and coagulation disorders.
• Patient with Advanced renal, hepatic and cardiac diseases.
• Preexisting lower extremity neurological abnormality, or neuropathy and difficulties in comprehending (NRS)

Once the study had been successfully completed, the data will be shared for other researchers

• The patients will be blind through the use of closed sealed envelops.
• The measurement will be collected by anesthesia nurse not participating in the study and blinded to its group.