Fig. 1

Percutaneous periarticular analgesic injection at 1 day after surgery. (For right knee.) a Inject 6.1 ml of drug solution into muscle belly of the vastus medialis just medial to the quadriceps tendon. b Direct the tip of the needle inward and inject 5 ml of drug solution into the muscle belly of the vastus medialis at a more medial site than the first infiltration.