Physical Address

304 North Cardinal St.
Dorchester Center, MA 02124

Gluteal Region


Atlas References

  • Netter: 492–494

  • McMinn: 316–319

  • Gray's Atlas: 301–303, 307, 314, 315

Before You Begin

Typically, you will not need to make additional skin incisions if you continue the dissection on the same cadaver on which you performed the dissection of the back in Chapter 2 ( Fig. 16.1 ).

Fig. 16.1, Surface anatomy of the gluteal region.

If not, place the cadaver in the prone position, and incise the skin and subcutaneous tissues along the iliac crest to the posterior superior iliac spine ( Figs. 16.2 and 16.3 ).

Fig. 16.2, Gluteal region with reflected skin, demonstrating dissection from the midline.

Fig. 16.3, Gluteal and posterior thigh regions with dermis reflected, revealing membranous layer of subcutaneous tissue (tela subcutanea).

Extend this incision medially to the intergluteal cleft, anterior to the area covering the perineum.

Skin and Superficial Fascia

  • o

    Reflect the skin and superficial fascia from the gluteal region and posterior thigh by making a longitudinal midline skin incision distally to the knee. Make a circumferential incision through the skin of the leg, just distal to the knee (see Figs. 16.2 and 16.3 ).

  • o

    There is typically a large amount of adipose tissue over the gluteus maximus muscle. Remove the adipose tissue and deep fascia in the gluteal region, exposing the gluteus maximus muscle ( Figs. 16.4 to 16.6 ).

    Fig. 16.4, Gluteal region with thoracolumbar fascia superiorly and reflected subcutaneous tissue, revealing gluteus maximus muscle inferiorly.

    Fig. 16.5, Further gluteal region dissection, revealing the gluteus medius (covered with fascia) muscle superiorly, the gluteus maximus muscle inferiorly, and the ischioanal fossa and tela subcutanea medially.

    Fig. 16.6, Closer view highlighting the gluteus medius (covered with fascia) muscle superiorly, the gluteus maximus muscle inferiorly, and the ischioanal fossa medially.

Dissection Tip

In many atlases, you will find the gluteus maximus muscle shown with no fat. To create a clean specimen, remove the fat between the fibers of the gluteus maximus muscle (see Fig. 16.6 ).

  • o

    Reflect the skin over the posterior portion of the thigh. The adipose tissue and deep fascia will be removed later during the dissection ( Fig. 16.7 ).

    Fig. 16.7, Posterior thigh region with skin and subcutaneous tissue reflected, revealing the posterior cutaneous nerve, fascia lata, and iliotibial tract.

Dissection Tip

As you delineate the superior and inferior borders of the gluteus maximus muscle, protect the posterior femoral cutaneous nerve from damage by being cautious along the inferior border of the gluteus maximus muscle.

Superficial Muscles

  • o

    Palpate the sacrotuberous ligament at the medial border of the gluteus maximus muscle by placing your fingertips into the ischioanal fossa ( Fig. 16.8 ).

    Fig. 16.8, Fingertips in gluteal region highlight gluteus medius superiorly, gluteus maximus inferiorly, and ischioanal fossa medially (palpation of lateral wall of fossa–obturator internus).

  • o

    Palpate the superior border of the gluteus maximus and insert your fingertips into the space between the gluteus maximus muscle and fascia over the gluteus medius muscle ( Fig. 16.9 ).

    Fig. 16.9, Gluteal region after dissecting superior border of gluteus maximus muscle superficially, revealing deeper gluteus medius fascia and muscle.

  • o

    Using your fingertips, lift the upper portion of the gluteus maximus muscle from the underlying gluteus medius muscle.

Dissection Tip

In most cadavers, the deep fascia and aponeurotic tissues along the superior border of the gluteus maximus muscle blend with those of the gluteus medius muscle. However, the muscular fibers of the gluteus medius muscle run almost perpendicular to the orientation of the gluteus maximus muscle, and the two muscles can be separated readily once you have clearly exposed their fibers.

Deep Dissection

  • o

    Make an incision at the lateral border of the gluteus maximus muscle, separating it from its connection to the iliotibial tract ( Fig. 16.10 ).

    Fig. 16.10, Reflecting the gluteus maximus muscle demonstrates the deeper lying muscle fibers of the gluteus medius muscle.

  • o

    Lift the gluteus maximus medially toward the sacrum, and identify the greater trochanter and overlying trochanteric bursa ( Figs. 16.11 and 16.12 ).

    Fig. 16.11, Reflection of superolateral border of gluteus maximus muscle, revealing superior gluteal artery and vein and trochanteric bursa.

    Fig. 16.12, Gluteal region with reflected gluteus maximus muscle, revealing gluteus medius and piriformis muscles and sciatic nerve.

Dissection Tip

The trochanteric bursa appears as loose connective tissue over the greater trochanter, intermingled with adipose tissue. It often is cleaned away during routine dissection.

  • o

    Reflect the gluteus maximus muscle medially from the gluteal tuberosity of the femur; remove the deep fascia and adipose tissue along its inferior border ( Fig. 16.13 ).

    Fig. 16.13, Connective tissue cleaned around posterior femoral cutaneous and sciatic nerves.

  • o

    Clean the sciatic and the posterior femoral cutaneous nerves from the adipose tissue, and trace them proximally from under the piriformis muscle ( Fig. 16.14 ). Once you identify the posterior femoral cutaneous nerve, identify its perineal branch traveling medially.

    Fig. 16.14, Reflected gluteus maximus muscle, revealing gluteus medius, rotator muscles (piriformis, superior/inferior gemelli, obturator internus, quadratus femoris), sciatic nerve, and posterior femoral cutaneous nerve.

Dissection Tip

To identify the posterior femoral cutaneous nerve, make a small opening through the fascia lata on the posterior aspect of the thigh, and identify the sciatic nerve. Medial to the sciatic nerve, you will be able to identify the posterior femoral cutaneous nerve. In some specimens, the sciatic nerve may split in the gluteal region, with one part traveling above or through and the other part below the piriformis muscle.

  • o

    The gluteus maximus muscle is partially attached to the sacrotuberous ligament. Palpate the sacrotuberous ligament as you did earlier (see Fig. 16.8 ); reflect the gluteus maximus muscle medially toward the sacrum, and expose the sacrotuberous ligament.

  • o

    Use a scalpel to cut the attachment of the gluteus maximus muscle from the sacrotuberous ligament. With scissors, cut the lateral portion of the sacrotuberous ligament, and free the gluteus maximus muscle ( Fig. 16.15 ).

    Fig. 16.15, Reflected gluteus maximus muscle revealing quadratus femoris muscle and tibial and common fibular nerves.

  • o

    Clean and expose the inferior gluteal vessels and nerve from the deep surface of the gluteus maximus muscle ( Figs. 16.16 and 16.17 ).

    Fig. 16.16, Gluteus maximus muscle reflected superiorly, revealing inferior gluteal vessels, quadratus femoris muscle, and tibial and common fibular nerves.

    Fig. 16.17, Closer view of Fig. 16.16 showing gluteal region with gluteus maximus reflected, revealing inferior gluteal artery and vein and sacrotuberous ligament.

  • o

    Lift the posterior femoral cutaneous and sciatic nerves, and clean the adipose and connective tissues from the structures that lie deep to the gluteus maximus muscle, such as the piriformis, obturator internus, and superior and inferior gemellus muscles ( Figs. 16.18 and 16.19 ).

    Fig. 16.18, Gluteal region with gluteus maximus reflected, revealing superior and inferior gluteal artery and vein oriented around piriformis muscle.

    Fig. 16.19, Gluteal region close-up view highlighting lateral rotator muscles (piriformis, superior/inferior gemelli, obturator internus, quadratus femoris) with sciatic nerve reflected medially.

  • o

    Inferior to the obturator internus and gemelli muscles, identify the quadratus femoris muscle.

Dissection Tip

The obturator internus, superior gemellus, and inferior gemellus muscles often are seen as a combined tripartite tendon with indistinguishable borders. With scissors or a probe, separate these three muscles at the margin of the lesser sciatic foramen.

  • o

    Identify the borders of the gluteus medius and tensor fasciae latae muscles. The tensor fasciae latae muscle arises from the anterior portion of the iliac crest. Its tendon is covered by fascia lata and continues distally as the iliotibial tract. Place your fingertips at the inferior border of the gluteus medius muscle and lift it upward ( Fig. 16.20 ).

    Fig. 16.20, Reflected gluteus maximus muscle reveals gluteus medius muscle, “lateral rotators” (piriformis, obturator internus, quadratus femoris muscles), and the sciatic nerve.

  • o

    At the superior space between the gluteus maximus and gluteus medius muscles, identify the superficial branch of the superior gluteal artery ( Figs. 16.21 and 16.22 ).

    Fig. 16.21, Gluteus maximus reflected, revealing piriformis muscle and superior and inferior gluteal neurovascular bundles.

    Fig. 16.22, Gluteus maximus muscle reflected, highlighting piriformis muscle and superior and inferior gluteal neurovascular bundles.

  • o

    Cut the attachment of the gluteus medius from the greater trochanter and reflect it superiorly. On its deep surface, identify the deep branch of the superior gluteal artery (see Fig. 16.22 ).

  • o

    The muscle exposed underneath the reflected gluteus medius is the gluteus minimus muscle. Deep and inferior to the sacrotuberous ligament, identify the nerve to the obturator internus, internal pudendal artery, its venae comitantes, and the pudendal nerve ( Fig. 16.23 ). The venae comitantes are the pair of veins that accompany the internal pudendal artery.

    Fig. 16.23, Gluteal region with reflection of the gluteus maximus muscle medially and the gluteus medius muscle superiorly, revealing the gluteus minimus muscle and the superior gluteal neurovascular bundle lying superficial to the gluteus minimus muscle.

Dissection Tip

The nerve to the quadratus femoris and inferior gemellus muscles is a small branch that may be found by retracting the sciatic nerve posteromedially; observe this small nerve traveling deep to the gemelli and obturator internus muscles.

You're Reading a Preview

Become a Clinical Tree membership for Full access and enjoy Unlimited articles

Become membership

If you are a member. Log in here

Related Posts