Femoral Triangle

FEMORAL TRIANGLE (trigonum femoris, s. Scarpae), occupies the upper-inner part of the anterior thigh and is bounded by the inguinal ligament and the medial border of the m. sartorii and m. adductor longi. Its apex is formed by the intersection of these muscles and is located 12-18 cm from the inguinal ligament, depending on the body type and muscular development. The muscular framework of the area consists of the m. ilio-psoas and adductor muscles (pectineus, adductor longus, etc.). The latter, together with the adjacent ilio-psoas, vastus medialis and sartorius, form a groove in which the inguinal-femoral lymph nodes, art. and v. femoralis and n. cruralis, with their branches and areolar tissue, are located. The movable skin within the femoral triangle is fused superiorly with the inguinal ligament, creating the inguinal skin fold (plica inguinalis). Incisions parallel to it do not gape; those directed at an angle, conversely, do not collapse and are more suitable for opening local purulent collections. The fascia subcutanea is easily divided into two layers, between which are located subcutaneous vessels, glands, nerves and fatty tissue, which sometimes reaches a thickness of 2-4 cm (see table I, fig. 1). The arteries (pudenda ext., epigastrica inf. and circumflexa ilium superficiales and the supplying glands arteriolae inguinales, branches of a. femoralis) penetrate into the subcutaneous layer, piercing the lamina cribrosa or, away from the oval window, the fascia lata. In addition to their accompanying veins of the same name, the v. saphena magna passes through the medial part of the femoral triangle, emptying into the femoral vein within the oval fossa (fossa ovalis). In 18% of cases, it is found here duplicated. The union of all these veins, sometimes with the v. saphena magna, and sometimes with the v. femoralis, creates in the area of the fossa ovalis a collector of venous blood from the subcutaneous vascular systems of the lower extremity, genital organs, perineum, anal part of the rectum and lower part of the abdominal wall, and through the subcutaneous vein (thoracicae longae epigastricae tegumentosae) creates an anastomosis of this collector with the subcutaneous veins of the axillary fossa. The lymph nodes, embedded here in two layers in the vascular and nerve-penetrated fatty tissue, are functionally connected with the same areas and in the same directions. Numbering from 6 to 12, sometimes more (according to Sappey - up to 20), they cover the fascia of the oval window with their bundle (see table II, fig. 3). The glands lying closer to the inguinal ligament in an oblique direction are called inguinal (lymphoglandulae inguinales) and, mainly, serve the abdominal wall, genital organs and anus. The lower groups, arranged vertically, are connected with the lower extremity, starting from the toes of the foot, and are called femoral (lgl. crurales) or 4 lower inguinal (lgl. inguin. infer.). The efferent vessels from these glands pierce the fascia cribrosa and empty into the deep system of the femoral canal, passing through Rosenmüller's gland to the glands of the iliac vessels. The subcutaneous nerves of the femoral triangle: n. inguinalis from n. genito-femoralis, emerging from lacuna vasorum lateral to a. femoralis, and two n. cutanei mediales from n. cruralis; they pierce the m. sartorius at different levels. All of them belong to the lumbar plexus (LI and LII). The deeper layers of the femoral triangle, i.e., the muscles, are covered by a broad fascia which superiorly divides into two sheets, front and back, funnel-like surrounding the vessels (see Femoral Canal). Part of the posterior sheet (fascia ilio-pectinea), attaching to the inguinal ligament and emin. ilio-pectinea, divides the space under the inguinal ligament into lacuna musculorum - for m. ilio-psoas and n. cruralis, and lacuna vasorum - for n. lumbo-inguinalis, a. and v. femoralis and the deep lymphatic system (see table II, fig. 4). Emerging from lac. vasorum, a. femoralis touches v. femoralis from within; the trunk of n. cruralis located lateral to it is separated from it by the fascia ilio-pectinea (see table I, fig. 2). Below fossae ilio-pectin., the artery goes in its fascial sheath in the direction of canalis adductorius (Hunteri) accompanied by n. sapheni, one of the branches of n. cruralis, having it on its lateral-anterior side. V. femoralis at this time shifts, passing behind the artery, and at the entrance to Hunter's canal lies lateral to the artery. Within the femoral triangle, in addition to the aforementioned cutaneous branches, a. femoralis gives off a. profunda femoris, from which mainly arise the supplying the adductor part of the thigh musculature and most of the hip joint a. circumflexa lateralis and medialis and 4 aa. perforantes for the posterior musculature and femur. Each of these arteries has two accompanying veins. Anastomoses of these branches with a. glutea sup. and inf., a. obturatoria and a. ischiadica form a collateral network playing a major role in ligation of a. femoralis. The level of origin of a. profundae femoris from the latter is measured 3-5 cm below the inguinal ligament. In the diffuse type of artery - it is closer to it, reaching 1-2 cm.