On the Organization of the Plexus lumbalis. I. On the Recognition of the Three-Layered Divisions and the Systematic Description of the Branches of the Human Femoral Nerve.

Abstract

The arrangement of the nerve bundles at the branching point of the femoral nerve (F), the interrelations of the branches each other and toward other nerves in the anterior region of the thigh, and the patterns and the anatomical features of both the running courses and the distributions of the branches were macroscopically studied, whereby some special findings were observed and the following results were obtained: 1) The periphery of the femoral nerve was fundamentally divided into superficial-deeply arranged three-layered divisions. Including the femoral branch of the genitofemoral nerve (Rf) and the femoral lateral cutaneous nerve (Cfl), the nerve branches at the anterior region of the thigh were totally divided into five-layered divisions. 2) The cutaneous branches of each division including Rf or Cfl could be classified in three groups: the medial cutaneous branches (m), the anterior cutaneous branches (a), and the lateral cutaneous branches (l). Based on the above results, the branches could be described systematically. Parallelly, several accessory bundles of F penetrating the psoas major muscle were observed, and two types of accessory femoral nerves (F') could be distinguished: One was higher on the segmentation and mainly flew into the 1st division of F. While the other distributed only to the medial region of the thigh. To clarify the segmental or stratifical natures of the branches of each division, F', and the interrelations among them, analyses of the nerve fibers were undertaken under the operational microscope. Consequently, the segmental differences between the divisions were distinct, and the medial branches or F'm obviously contained ventral components. Thus, when a component originated from the higher segments, it distributed to the proximal region generally taking a superficial course; when it originated from the lower ones, it distributed to the distal region of the thigh forming the deeper division; when it belonged to the ventral stratum, it distributed to the medial region; and when it belonged to the dorsal stratum, it distributed to the lateral region. On the occasion of the fiber analysis, it was found that each root of the lumbar nerve was generally divided into two or three subsegmentally-arranged subroots that divided themselves into some fasciculi arranged micro-segmentally. A minute analysis of the segmentations of the nerves became possible because of the above characteristics.

Classification and Fascicular Analysis of Variant Branching Pattern of Femoral Nerve for Microsurgical Intervention: A Series of Thirteen Cadavers

“…Such branching pattern of the femoral nerve is similar to the present study. Aizawa (1992) reported that the medial cutaneous nerve branches and the vastus medialis, vastus intermedius, vastus lateralis, and rectus femoris nerves were arranged medially to laterally. This pattern is consistent with the present study with the exception that the intermediate cutaneous nerve of the thigh and the saphenous nerve lay between the medial cutaneous nerve of the thigh and the nerve to the vastus medialis, whereas Gustafson et al did not mention the intermediate cutaneous nerve of the thigh.…”

Human fetal topographical anatomy of the femoral triangle in relation with change in the hip joint position.

“…Therefore, the hypothesized rotation of nerves (see the Introduction) was likely to occur postnatally as well as in the late-stage fetuses. Aizawa (1992) classified human femoral nerve branches into three types, and provided an excellent schema regarding the rotation of the femoral nerve. However, the origin of the deep femoral artery in the lateral side of the mother artery in fetuses might not support the hypothetical medial rotation: the lateral rotation may be required to move the origin to the posterior aspect of the femoral artery.…”

“…In spite of the fetal hip joint position, some Japanese anatomists have hypothesized that a long axis of the dermatomes and myotomes (segmental nerve supplying areas) in the human lower extremity is twisted or rotated "medially" at the hip joint (Aizawa, 1992;Ogoshi et al, 2001;Kodama, 2000;Kawashima and Sasaki, 2010). According to their understanding, not only the femoral nerve branches but also the iliofemoral ligament in adults suggests the twisting or rotation in the "fetal period".…”

Reasonable classical concepts in human lower limb anatomy from the viewpoint of the primitive persistent sciatic artery and twisting human lower limb

“…In an excellent description of the peripheral nerves of the lower limb, Aizawa (1992) classified human femoral nerve branches into three layers, and provided an excellent schema regarding the rotation of the femoral nerve. Although the twisting lower limb has thus been disclosed fragmentary, the anatomical representation between the muscles and nerves on the twist in entire lower limb has never attempted until our report .…”

“…Therefore, most anatomists, especially Japanese gross anatomists, have observed and discussed anatomical structures and their morphogenesis on the basis of the vertebrate body plan, as described in studies on the limb girdle and forelimb (Aizawa, 1992;Aizawa et al, 1995Aizawa et al, , 1996Aizawa et al, , 1999Akita, 1992aAkita, , 1992bAkita et al, 1992Akita et al, , 1994Akita et al, , 1995Akita et al, , 1999Akita et al, , 2002Arakawa et al, 2005;Aung et al, 2001;Chiba, 1983Chiba, , 1984Chiba, , 1986Chiba, , 1992Chiba et al, 1994;Homma and Sakai, 1991Honma et al, 1998;2003Horiguchi, 1980Horiguchi, , 1981Horiguchi, , 1986Kasai and Yamamoto, 1996;Kasai and Chiba, 1980;Kasai et al, 1989aKasai et al, , 1989bKato andSato, 1978, 1984;Kato, 1989;Kida and Ishida, 1989;Kodama et al, 1992aKodama et al, , 1992bKoizumi, 1989;Koizumi andSakai, 1995, 1997;Koizumi et al, 1999;Kudoh et al, 1999;Kudoh and Saki, 2007;Okamoto et al, 2004;Sato K, 1980;…”