Adductor Canal Block With or Without Biceps Femoris Short Head Block in Total Knee Arthroplasty

Effect of Adding a Biceps Femoris Short Head Block to an Adductor Canal Block on Postoperative Pain and Functional Outcomes After Total Knee Arthroplasty: A Randomized Controlled Trial

Total knee arthroplasty is associated with moderate to severe postoperative pain, which may delay mobilization and recovery. Multimodal analgesia including regional anesthesia techniques is widely used to improve outcomes. The adductor canal block (ACB) provides anteromedial knee analgesia but may not adequately cover the posterolateral region.

The biceps femoris short head (BiFeS) block is a novel motor-sparing regional anesthesia technique targeting the posterolateral capsule of the knee. This randomized controlled trial aims to compare the analgesic efficacy and functional outcomes of ACB combined with BiFeS block versus ACB alone in patients undergoing total knee arthroplasty.

The primary outcome is posterior knee pain at postoperative 6 hours. Secondary outcomes include pain scores within 48 hours, opioid consumption, early and late functional recovery, and opioid-related adverse effects.

Inclusion Criteria:

• ASA I-III
• Adult patients undergoing unilateral primary TKA
• Planned spinal anesthesia
• Written informed consent

Exclusion Criteria:

• Coagulopathy
• Drug allergy
• BMI > 35
• Renal/hepatic failure
• Chronic pain or opioid use
• Depression or psychiatric disorder
• Revision or bilateral TKA
• Neurological deficits
• Preoperative ROM < 90°