An adductor canal block (ACB) is preferred over femoral nerve block (FNB) for total knee arthroplasty (TKA) because it achieves similar analgesia with which important functional advantage?

• A ACB provides better coverage of posterior knee pain than FNB
• B ACB has lower risk of vascular puncture than FNB due to its superficial location
• C ACB provides longer duration of analgesia than FNB with the same LA volume
• D ACB is purely sensory (blocks saphenous and nerve to vastus medialis) with minimal quadriceps weakness, enabling early mobilisation and physiotherapy ✓

Explanation

The adductor canal block targets the saphenous nerve and nerve to vastus medialis in the subsartorial (adductor) canal, providing sensory analgesia to the anteromedial knee without blocking the motor branches of the femoral nerve to the quadriceps. FNB causes significant quadriceps weakness, increasing fall risk and delaying physiotherapy and mobilisation in TKA enhanced recovery protocols. For posterior knee pain, the iPACK block (interspace between the popliteal artery and the posterior capsule of the knee) is added to the ACB.

Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.