Sciatic nerve block via posterior Labat approach is more efficient than lateral popliteal approach using a double-injection technique: a prospective, randomized comparison

Anesthesiology. 2004 Jul;101(1):138-42. doi: 10.1097/00000542-200407000-00022.


Background: For peripheral nerve blockade, the double-injection technique proved to be superior to a single injection in previous investigations. The current study was designed to compare onset time and efficacy of two different double-injection approaches for sciatic nerve block with 0.75% ropivacaine.

Methods: A total of 50 patients undergoing foot surgery were randomly assigned to receive sciatic nerve blockade by means of the classic (Labat) posterior approach (n = 25) or a lateral popliteal approach (n = 25). All blocks were performed with the use of a nerve stimulator, and both major components of the sciatic nerve (tibial and common peroneal nerves) received separately 10 ml ropivacaine, 0.75%. Success rate was defined as a complete sensory and motor block associated with pain-free surgery.

Results: A greater success rate was observed in the classic group (96%) as compared with the popliteal group (68%; P < 0.05). A general anesthetic became necessary in six patients (24%) with the lateral popliteal approach and none with the classic approach (P < 0.05). The onset of complete sensory and motor blockade was significantly faster in the classic group (12 +/- 6 min) as compared with the popliteal group (26 +/- 10 min; P < 0.05).

Conclusion: A double injection with a relatively low volume of 0.75% ropivacaine generated a higher success rate and a shorter onset time of sensory and motor blockade after the classic Labat approach than after a lateral popliteal approach.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Amides
  • Anesthetics, Local
  • Female
  • Humans
  • Male
  • Middle Aged
  • Motor Neurons / drug effects
  • Nerve Block / methods*
  • Peroneal Nerve / physiology
  • Prospective Studies
  • Ropivacaine
  • Sciatic Nerve* / anatomy & histology
  • Survival Analysis
  • Tibial Nerve / physiology


  • Amides
  • Anesthetics, Local
  • Ropivacaine