Gluteal Region & Important anastomosis in the thighDr. Vohra

Gluteal Region The bulky region of hip (the buttocks)

Vessels:Superior & inferior gluteal arteries Nerve:Sciatic, posterior cutaneous nerve of thigh, superior gluteal, inferior gluteal, nerve to quadratus femoris, nerve to obturator internus & pudendal nerve Contents of the Gluteal RegionForaminaGreater sciatic & lesser sciatic Ligaments Sacrotuberous & sacrospinous Ligaments MusclesGluteal maximus, gluteal medius, gluteal minimus, tensor fasciae latae, piriformis, obturator internus, superior/inferior gemelli & quadratus femoris

Ligaments of the Gluteal Region The function of these ligaments is to stabilize the sacrum and prevent its rotation at the sacroiliac joint by the weight of the vertebral column

Foramina of the Gluteal RegionIs formed by the greater sciatic notch of the hip bone and the sacrotuberous and sacrospinous ligaments. Structures exit the foramen PiriformisSciatic nervePosterior cutaneous nerve of the thighSuperior and inferior gluteal nervesNerves to the obturator internus and quadratus femorisPudendal nerve Superior and inferior gluteal arteries and veinsInternal pudendal artery and veinGreater Sciatic Foramen

Is formed by the lesser sciatic notch of the hip bone and the sacrotuberous and sacrospinous ligaments. Structures exit the foramen Tendon of obturator internus muscleNerve to obturator internusPudendal nerveInternal pudendal artery and veinLesser Sciatic Foramen

Muscles of the Gluteal Region

MuscleOriginInsertionNerve SupplyNerve RootsActionGluteus maximusOuter surface of ilium, sacrum, coccyx, sacrotuberous ligamentIliotibial tract and gluteal tuberosity of femurInferior gluteal nerveL5; S1, 2Extends and laterally rotates hip joint; through iliotibial tract, it extends knee jointGluteus mediusOuter surface of iliumLateral surface of greater trochanter of femurSuperior gluteal nerveL5; S1Abducts thigh at hip joint; tilts pelvis when walking to permit opposite leg to clear groundGluteus minimusOuter surface of iliumAnterior surface of greater trochanter of femurSuperior gluteal nerveL5; S1Abducts thigh at hip joint; tilts pelvis when walking to permit opposite leg to clear groundTensor fasciae lataeIliac crestIliotibial tractSuperior gluteal nerveL4; 5Assists gluteus maximus in extending the knee jointPiriformisAnterior surface of sacrumUpper border of greater trochanter of femurFirst and second sacral nervesL5; S1, 2Lateral rotator of thigh at hip jointObturator internusInner surface of obturator membraneUpper border of greater trochanter of femurSacral plexusL5; S1Lateral rotator of thigh at hip jointGemellus superiorSpine of ischiumUpper border of greater trochanter of femurSacral plexusL5; S1Lateral rotator of thigh at hip jointGemellus inferiorIschial tuberosityUpper border of greater trochanter of femurSacral plexusL5; S1Lateral rotator of thigh at hip jointQuadratus femorisLateral border of ischial tuberosityQuadrate tubercle of femurSacral plexusL5; S1Lateral rotator of thigh at hip joint

Gluteus Maximus and Intramuscular InjectionsGreat thickness of gluteus maximus muscle makes it ideal for intramuscular injections. To avoid injury to the underlying sciatic nerve, the injection should be given well forward on the upper outer quadrant of the buttock.

Nerves of the Gluteal RegionSciatic NerveIs a branch of the sacral plexus (L4 and 5; S1, 2, and 3), emerges from the pelvis through the lower part of the greater sciatic foramen. It is the largest nerve in the body and consists of the tibial and common peroneal nerves bound together with fascia. The sciatic nerve usually gives no branches in the gluteal region.Posterior Cutaneous Nerve of the ThighIs a branch of the sacral plexus, enters the gluteal region through the lower part of the greater sciatic foramen below the piriformis muscle.Superior Gluteal NerveIs a branch of the sacral plexus, leaves the pelvis through the upper part of the greater sciatic foramen above the piriformis.

Inferior Gluteal NerveIs a branch of the sacral plexus, leaves the pelvis through the lower part of the greater sciatic foramen below the piriformis.Nerve to the Quadratus FemorisA branch of the sacral plexus, leaves the pelvis through the lower part of the greater sciatic foramen. Ends by supplying the quadratus femoris and the inferior gemellus.Pudendal Nerve & the Nerve to the Obturator InternusBranches of the sacral plexus, they leave the pelvis through the lower part of the greater sciatic foramen, below the piriformis

Arteries of the Gluteal RegionSuperior & Inferior Gluteal Artery are branches from the internal iliac artery.

Important anastomosis in the thigh

The Trochanteric AnastomosisThe trochanteric anastomosis provides the main blood supply to the head of the femur. The nutrient arteries pass along the femoral neck beneath the capsule. The following arteries take part in the anastomosis: the superior gluteal artery, the inferior gluteal artery, the medial femoral circumflex artery, and the lateral femoral circumflex artery.

The Cruciate AnastomosisThe cruciate anastomosis is situated at the level of the lesser trochanter of the femur and, together with the trochanteric anastomosis, provides a connection between the internal iliac and the femoral arteries. The following arteries take part in the anastomosis: the inferior gluteal artery, the medial femoral circumflex artery, the lateral femoral circumflex artery, and the first perforating artery, a branch of the profunda artery.