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Midfemoral Block: A New Lateral Approach to the Sciatic Nerve

Dang, C. Pham MD

doi: 10.1213/00000539-199906000-00052
Letters to the Editor

Service d'Anesthesie-Reanimation Chirurgicale; Hotel-Dieu; 44093 Nantes cedex 1, France.

To the Editor:

A new lateral approach to the sciatic nerve is described as the midfemoral block. The surface landmarks are the palpable greater trochanter (GT), the great axis of the femur palpated. A line is drawn from the posterior margin of greater trochanter toward the knee, parallel to the femur. The puncture site is situated on this line at the middle of the thigh. At this point, in contrast to the popliteal fossa, the sciatic nerve is not yet divided, and is reached at 3-8 cm of depth. The procedure is conveniently performed while the patient is in the supine position with the limb raised on a pillow. The operator places one hand on the limb to move to zero rotation and exposes the line. With the other hand, the operator inserts a stimulating needle perpendicularly to the skin (Figure 1). The needle is advanced toward the sciatic nerve until evoking foot movements. The mean duration of complete sciatic blockade was 14 h after the administration of 20-30 mL of 0.5% adrenalinated bupivacaine. The midfemoral sciatic was combined with femoral block in 50 patients after total knee replacements and in 10 for foot surgeries. The combined blocks were performed with one pack of Plexus Mini-set[registered sign] (Pajunk, Geisingen, Germany).

Figure 1

Figure 1

C. Pham Dang, MD

Service d'Anesthesie-Reanimation Chirurgicale; Hotel-Dieu; 44093 Nantes cedex 1, France

© 1999 International Anesthesia Research Society