Adductor canal block (ACB) has emerged as an option for postoperative regional analgesia in patients undergoing total knee arthroplasty (TKA).

Various approaches to the performance of peripheral nerve blocks for postoperative pain control in patients undergoing TKA have been described in the literature. These approaches include lumbar plexus block, femoral nerve block (FNB), with or without a sciatic nerve block, and most recently the ACB. FNB is a commonly used modality for postoperative analgesia after TKA. It is considered by some as the gold standard or the cornerstone of postoperative analgesia after TKA. However, FNB reduces quadriceps muscle strength essential for mobilization and active contribution in any physical rehabilitation program. Quadriceps weakness places the patients at risk of falling. which may be detrimental to postoperative recovery. The ACB has recently emerged as an appealing alternative to FNB as it is predominately a sensory nerve block of a more distal branch of the femoral nerve ( the saphenous nerve).

Inclusion Criteria:

• Patients scheduled for primary total knee arthroplasty with
• American Society of Anesthesiologists (ASA) physical status I -III,
• mentally competent and able to give consent for enrollment in the study.

Exclusion Criteria:

1. Patient younger than 18 years old or older than 70 years old
2. Allergy to local anesthetics, systemic opioids (fentanyl, morphine, hydromorphone, and any of the drugs included in the multimodal perioperative pain protocol.
3. Revision surgeries were excluded.
4. Impaired kidney functions and patients with coagulopathy were also excluded.
5. Chronic pain syndromes and patients with chronic opioid use defined as the use of regular daily doses of systemic narcotics for the past 6 months prior to the surgery.
6. BMI of 40 or more
7. Pregnancy (positive urine pregnancy test result in Preop area on the morning of surgery)

A computer-generated randomization table will be used for patient allocation to one of the two study groups, The SACB group, and the CACB group. Randomization was done in blocks of 10 patients each. Patients' assignments were written in a sealed envelope that was only open after the patient consents to the study.