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 artery4,5 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.
Relevant anatomy for the 3-in-1 block on sagittal
T2-weighted MRI. (A, Anterior; P, posterior; lFV, left femoral vein; UB,
MRI image after administration of local anesthetic on
sagittal T2-weighted MRI. (A, Anterior; P, posterior; lFV, left femoral
vein; LA, local anesthetic; UB, urinary bladder.)
One of the main proposed advantages of the 3-in-1 block was the ability
to achieve block of the obturator nerve using this approach. However, most
investigators have used clinical or electrophysiologic methods to analyze
analgesia levels and involved nerves. In clinical practice, however, the
obturator nerve has never been shown to be anesthetized effectively using this
approach.6,7 Cauhepe et al.8
investigated the anesthetic route of the 3-in-1 blocks using standard pelvic
radiography and computed tomography and reported two unexpected
distributions of local anesthetic. The first type consisted of an internal
distribution of local anesthetic toward the psoas major muscle. The second
type was an external diffusion of local anesthetic in front of the iliac
muscle. The main result of this study in human cadavers was that the local
anesthetic never reached the obturator nerve. Capdevila et
al.9 reported that the local anesthetic used in 3-in-1
blocks spreads under the iliac fascia, but rarely to the lumbar plexus. Both
techniques resulted in poor blocks of the obturator nerve.
Indications & Contraindications
The following are indications for using 3-in-1 block:
Surgical procedures in the sensory areas of the femoral, lateral femoral
cutaneous, and anterior branches of the obturator nerves (eg, skin surgery,
Perioperative pain therapy of hip fractures (additional block of the sciatic
nerve is necessary)
Perioperative pain therapy of femoral shaft fractures (additional block of ...
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