Hadzic's Regional Anesthesia > Part III. Clinical Practice of Regional Anesthesia > Section Six. Blocks for the Lower Extremity > Chapter 36. Three-in-One Block Peter Marhofer, MD, Stephan Kapral, MD, Xavier Sala-Blanch, MD

Three-in-One Block: Introduction

"The initial description of the 3-in-1 block was published by Winnie et al.¹ in 1973 involving a small number of patients. The authors postulated that a block of the entire lumbar plexus can be accomplished by a single perivascular injection slightly distal to the inguinal ligament. Consequently, a single injection should result in anesthesia of the femoral, the lateral femoral cutaneous, and obturator nerves. Winnie et al.^2,3 suggested that the underlying mechanism of this regional anesthetic technique should be a cephalad distribution of the local anesthetic along a fascial layer. This hypothesis, however, was never confirmed clinically. Moreover, an MRI study clarified the spread of local anesthetic after an inguinal injection of local anesthetic lateral to the femoral artery^4,5 and concluded that the distribution of local anesthetic follows a lateral and slightly medial direction, but never a cephalad direction. Figures 36–1 and 36–2 illustrate that the spread of local anesthetic does not follow a proximal direction.The following are indications for using 3-in-1 block:The position of the patient is supine with both legs extended and the leg to be blocked with 15–30 degrees lateral rotation. After standard preparation (monitoring, intravenous access, sterile preparation of the needle insertion area, and skin anesthesia), the nerve stimulation needle is connected to a nerve stimulator. The needle insertion site is 1–2 cm distal to the inguinal ligament with an angle..."