Abstract:

Objective To reveal the fascial configuration in front of the femoral nerve and to identify accurate anatomical landmarks for the ultrasound-guided femoral nerve block. Methods Three adult pelvices tissues were transversely sectioned for epoxy sheet plastination. Ultrasound-guided femoral nerve block images were collected from 36 patients to compare the result of the plastination study. Results Plastinated slices displayed that the fascia lata was extended from sartorius muscle laterally to the front wall of femoral sheath medially. The fascia lata covered iliac fascia, femoral nerve, iliopsoas and femoral sheath. In four out of six sides, the double layers of fascia lata did not unite in the medial border of the sartorius muscle, but in the remaining two sides, they merged into a single layer in the front of the sartorius muscle. The iliac fascia tightly covered femoral nerve and iliopsoas. Medially, it passed the posterior-lateral femoral sheath and then became the pectineal ligament. The iliac fascia did not form the fascia sheath-like structure to wrap the femoral nerve. The fascia in front of femoral nerve was clearly displayed under ultrasound. In 30 out of 36 cases, the fascia lata had two layers and other six cases showed that the fascia lata had one layer. Conclusion The iliac fascia is closely related to the femoral nerve. It can be used as an ideal anatomical landmark for ultrasound-guided femoral nerve block. The fascia lata may likely be misidentified as the iliac fascia.

Key words: Femoral nerve, Iliac fascia, Ultrasound, Nerve block, Sheet plastination, Human