Thigh and Leg

Atlas References

• Netter: 480–485, 490–491

• McMinn: 320–327

• Gray's Atlas: 299, 300, 306–317

Before You Begin

Palpate the following bony landmarks on the cadaver or on yourself:

• Anterior superior iliac spine

• Pubic tubercle

• Pubic symphysis

• Greater trochanter of femur

• Medial and lateral femoral condyles

• Patella

• Tibial tuberosity

• Head and neck of fibula

• Medial and lateral malleoli of tibia and fibula, respectively

Dissection Steps

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  Make a horizontal skin incision on the thigh 2 to 3 cm (~1 inch) inferior and parallel to the inguinal ligament.

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  Leave the skin intact over the external genitalia.

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  At the midpoint of this horizontal incision, make a vertical incision to the anterior portion of the patella.

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  Make an encircling incision around the knee ( Fig. 17.1 ).

  

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  Reflect the skin medially over the thigh, and identify the superficial veins ( Fig. 17.2 ).

  

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  Continue the dissection by making a vertical incision from the knee toward the ankle ( Fig. 17.3 ).

  

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  Make a transverse incision between the malleoli.

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  Reflect the skin of the leg laterally ( Fig. 17.4 ).

  

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  Start exposing the superficial veins of the leg and thigh ( Fig. 17.5 ).

  

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  Identify the great saphenous vein and saphenous nerve ( Fig. 17.6 ).

  

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  Clean the superficial fascia over the great saphenous vein, starting from the ankle toward the knee ( Fig. 17.7 ).

  

Anatomy Note

Around the knee, the saphenous nerve is located deep to the great saphenous vein. In the leg medial to the tibia, however, the great saphenous vein runs parallel with the saphenous nerve ( Fig. 17.8 ). The great saphenous vein arises from the medial side of the dorsal venous arch of the foot and ascends anterior to the medial malleolus, along the medial side of the leg and thigh, finally draining into the femoral vein.

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  Identify the great saphenous nerve and note its relationship to the saphenous vein medial to the tibia.

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  Remove the skin from the posterior aspect of the leg to the ankle ( Fig. 17.9 ).

  

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  Leave the superficial and deep fasciae (crural fascia) intact.

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  Identify the small (lesser) saphenous vein, which begins from the lateral aspect of the dorsal venous arch of the foot.

Anatomy Note

The small saphenous vein ascends just inferior to the lateral malleolus, accompanying the sural nerve, and finally drains into the popliteal vein ( Fig. 17.10 ).

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  Identify the sural nerve.

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  Observe the sural nerve and the small saphenous vein as they penetrate the deep crural fascia to travel to the popliteal fossa ( Fig. 17.11 ).

  

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  On the anterior part of the leg, on its medial side over the patellar ligament, expose the infrapatellar branch of the saphenous nerve ( Fig. 17.12 ).

  

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  Follow the great saphenous vein toward the thigh, and clean the fat off the superficial fascia around the vein ( Fig. 17.13 ).

  

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  Expose the great saphenous vein toward the fossa ovalis (saphenous hiatus), the opening in the deep fascia, where the vein travels through to drain into the femoral vein.

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  Expose the superficial and deep perforating tributaries of the great saphenous vein ( Fig. 17.14 ).

  

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  Start cleaning fat from around the great saphenous vein, extending the dissection medially and laterally ( Fig. 17.15 ).

  

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  Do not cut through the deep fascia of the thigh, but identify the anterior cutaneous branches of the femoral nerve intermingled with the tributaries of the great saphenous vein.

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  Lateral to the vein, identify the rectus femoris muscle.

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  On top of and lateral to the muscle, identify the lateral femoral cutaneous nerves ( Fig. 17.16 ).

  

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  Cut the distal ends of the cutaneous nerves you previously dissected.

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  Reflect the nerves medially and preserve them.

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  Cut the deep fascia of the thigh, fascia lata, and expose the sartorius muscle ( Fig. 17.17 ).

  

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  Continue reflecting the fascia lata over the vastus medialis muscle ( Fig. 17.18 ).

  

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  Expose the quadriceps femoris muscles of the extensor compartment of the thigh; the vastus medialis, lateralis, and intermedius muscles; and the rectus femoris muscle and their tendons attaching to the patella.

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  Continue the exposure by noting the fascia lata laterally and its thickened distal part, the iliotibial tract, attaching to the lateral condyle of the tibia ( Fig. 17.19 ).

  

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  Reflect the rectus femoris muscle medially, and expose the vastus intermedius muscle underneath ( Fig. 17.20 ).

  

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  Place the cutaneous nerves back in their original position over the dissected muscles, and appreciate their location ( Fig. 17.21 ).

  

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  Expose the femoral vein, and dissect out the cribriform fascia, which fills the saphenous hiatus ( Fig. 17.22 ).

  

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  Cut the femoral sheath around the femoral artery and vein.

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  Note the relationship between the femoral artery and vein; the femoral artery is located lateral to the femoral vein. The femoral nerve lies lateral to the femoral artery ( Fig. 17.23 ).

  

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  Clean the fascia covering the femoral artery and vein, and trace these vessels underneath the inguinal ligament to the femoral triangle.

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  Continue removing fat, and expose the adductor longus and gracilis muscles medially ( Fig. 17.24 ).

  

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  Retract the femoral artery laterally from the femoral vein, and deep between these vessels note the iliopsoas muscle lying over the anterior aspect of the hip joint ( Fig. 17.25 ).

  

Anatomy Note

The area you just dissected is called the femoral triangle, formed by the inguinal ligament superiorly, the sartorius muscle laterally, and the adductor longus muscle medially. The pectineus and iliopsoas muscles form the floor of the triangle ( Plate 17.1 ).

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  Cut the smaller venous tributaries draining to the femoral vein for better exposure of the femoral triangle.

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  Medial to the iliopsoas muscle, note the pectineus muscle, and more medially, the adductor longus muscle.

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  Clean the femoral artery and vein proximal to the femoral canal, and trace the lateral femoral cutaneous nerve underneath the inguinal ligament, just medial to the anterior superior iliac spine ( Fig. 17.26 ).

  

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  Cut the sartorius muscle at its distal quarter, and expose the adductor canal ( Figs. 17.27 and 17.28 ).

  
  

Anatomy Note

The adductor canal is formed by the adductor magnus, adductor longus, and vastus medialis muscles. The canal begins at the apex of the femoral triangle and ends at the adductor hiatus, which is the canal formed by the adductor magnus tendon at the posterior knee. After passing through the adductor hiatus and reaching the posterior part of the knee, the femoral artery and femoral vein are termed the popliteal artery and popliteal vein ( Fig. 17.29 ).

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  Within the adductor canal, expose and identify the femoral artery, femoral vein, saphenous nerve, nerve to the vastus medialis muscle, and descending genicular artery (see Fig. 17.29 ).

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  Expose the aperture in the tendon of insertion of the adductor magnus, the adductor hiatus ( Fig. 17.30 ).

  

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  Identify the nerve to the vastus medialis muscle, and trace the nerve to its termination on the muscle.

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  Distal to the level of the adductor hiatus, trace the saphenous nerve and expose it to the posteromedial aspect of the knee where it meets the great saphenous vein.

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  With scissors, cut the femoral vein a few centimeters inferior to the femoral canal and reflect it inferiorly ( Figs. 17.31 and 17.32 ).

  
  

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  Fully expose the pectineus, adductor longus, and gracilis muscles.

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  Pull the femoral artery medially, and dissect out its branches ( Figs. 17.33 and 17.34 ).

  
  

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  Identify the lateral circumflex femoral artery, and expose its descending branch supplying the vastus lateralis, which travels in the muscle between the vastus lateralis and vastus intermedius (this is a fairly constant dissection landmark).

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  Continue the dissection by exposing the deep femoral artery (profunda femoris) deep to the adductor longus muscle (see Figs. 17.33 and 17.34 , Plate 17.2 ).

  

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  Expose several of the perforating branches mainly supplying the posterior compartment of the thigh.

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  Identify the medial circumflex femoral artery, and expose it between the iliopsoas and pectineus muscles.

If time permits, from the exposed femoral artery, look for the following arteries:

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  Superficial circumflex iliac artery, which travels toward the anterior superior iliac spine.

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  S uperficial epigastric artery, which travels upward toward the anterior abdominal wall, crossing over the inguinal canal.

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  Superficial and deep external pudendal vessels typically are small arteries that anastomose with branches of the internal pudendal artery. Do not attempt to identify these two vessels.

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  In the space between the adductor longus and vastus intermedius muscles, identify the adductor brevis muscle ( Fig. 17.35 ).

  

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  With scissors, cut the pectineus muscle just inferior to the inguinal ligament, and reflect it laterally ( Fig. 17.36 ).

  

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  Note the adductor brevis fascia over the proximal part of the adductor brevis muscle. Remove the fascia carefully, and expose the obturator artery and nerve ( Figs. 17.37 and 17.38 ).

  
  

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  Reflect the adductor brevis muscle laterally, and identify the posterior division of the obturator nerve innervating the adductor magnus.

Laboratory Identification Checklist