Sciatic nerve block: a new midfemoral lateral approach. Benefit of the combination with a (3 in 1) block for invasive knee surgery

Objective: To describe a new midfemoral lateral approach for the sciatic ne rve block. Its combination with the "3 in 1" block was tested for postopera tive analgesia following major surgery of the knee. Study design: Descriptive, anatomical and clinical study prospective. Patients: After testing in four unembalmed corpses the new approach was app lied to 42 ASA 1-2 patients, in combination with a continuous "3 in 1" bloc k. Methods: The new approach was analysed for reliability of the surface landm arks (a line drawn from the posterior margin of the greater trochanter towa rds the knee and parallel to the femur) and block extent assessed on the fo ot. Its combination with the "3 in 1" block was evaluated with a visual ana logue scale (VAS) scoring, for postoperative analgesia after total knee art hroplasty. Results: The sciatic nerve was located in less than 10 min. A block of the sciatic nerve was fully achieved in all patients. Its median duration was 1 6 h. The median VAS score at rest was 0 mm (sciatic bloc + continuous block "3 in 1"), but increased to 40 mm (block "3 in 1" alone). Conclusion: The new lateral midfemoral sciatic block is easy to master. Com bined with a continuous "3 in 1" block, it provides excellent analgesia dur ing the early postoperative period after major surgery of the knee. (C) 200 0 Editions scientifiques et medicates Elsevier SAS.