Gluteal Region Anatomy Overview - Nerves, Muscles, and Vessels

1. GLUTEAL REGION Prof. Saeed Abuel Makarem

2. CUTANEOUS SUPPLY • UPPER MEDIAL QUADRANT: posterior rami of • L1,2,3 and S1,2,3 • UPPER LATERAL QUADRANT: lateral branches of • Subcostal & Iliohypogastric nerves • LOWER MEDIAL QUADRANT: Gluteal branches of posterior cutaneous nerve of the thigh • LOWER LATERAL QUADRANT: posterior branch of lateral cutaneous nerve of the thigh Prof. Saeed Abuel Makarem

3. CONTENTS • MUSCLES: • GLUTEI • Gluteus maximus • Gluteus medius • Gluteus minimus • GROUP OF SMALL MUSCLES (Lateral rotators of thigh) • Piriformis • Obturator internus • Gemilli (superior & inferior) • Quadratus femoris Prof. Saeed Abuel Makarem

4. CONTENTS • NERVES : • (FROM SACRAL PLEXUS): • Superior & inferior gluteal, • Posterior cutaneous nerve of thigh, • Nerve to obturator internus, • Nerve to quadratus femoris, Pudendal nerve, • Sciatic nerve. • VESSELS : • (INTERNAL ILIAC ARTERY): • Superior & inferior gluteal, Internal pudendal vessels. Prof. Saeed Abuel Makarem

5. GLUTEI • Gluteus maximus: • Main origin: • back of sacrum & coccyx • back of sacrotuberous ligament • Other origin: • gluteal surface of ilium, behind posterior gluteal line • Gluteus minimus: • gluteal surface of ilium, between inferior & middle gluteal lines • Gluteus medius: • gluteal surface of ilium, between middle & posterior gluteal lines Prof. Saeed Abuel Makarem

6. GLUTEI INSERTIONS • Gluteus minimus: • anterior surface of greater trochanter • Gluteus medius: • lateral surface of greater trochanter • Gluteus maximus: • Main insertion: • iliotibial tract • Other insertion: • gluteal tuberosity of femur Prof. Saeed Abuel Makarem

7. GLUTEI NERVE SUPPLY & ACTION • Gluteus medius & minimus: • Nerve supply: • Superior gluteal nerve • Action: • Abduction & medial rotation of hip joint • Gluteus maximus: • Nerve supply: • Inferior gluteal nerve • Main action: • Extension & lateral rotation of hip joint • Other action: • Through its attachment to iliotibial tract, it stabilizes the femur on tibia during standing Prof. Saeed Abuel Makarem

8. Group of small muscles • ALL MUSCLES HAVE SIMILAR ACTION: • Control movements of the hip join • Help in lateral rotation of the hip Prof. Saeed Abuel Makarem

9. Group of small muscles • QUADRATUS FEMORIS • Origin: • lateral border of ischial tuberosity • Insertion: • quadrate tubercle & intertrochanteric crest • Nerve supply: • nerve to quadratus femoris Prof. Saeed Abuel Makarem

10. Group of small muscles • OBTURATOR INTERNUS • Origin: inner surface of obturator membrane, inner margin of obturator foramen & wide area above & behind it • Insertion: the tendon passes through LSF to be inserted into theinner surface of greater trochanter. • Nerve supply: • nerve to obturator internus • SUPERIOR & INFERIOR GEMILLUS • Origin: upper part & lower part of lesser sciatic notch respectively • Insertion: upper part & lower part of tendon of obturator internus • Nerve supply: • nerve to obturator internus supply superior gemellus • nerve to quadratus femoris supply inferior gemellus Prof. Saeed Abuel Makarem

11. Group of small muscles • PIRIFORMIS • Origin: • pelvic surface of middle 3 sacral vertebrae. • Insertion: • the msucle passes through GSF to be inserted into the upper border of greater trochanter • Nerve supply: • anterior rami of S1,2 Prof. Saeed Abuel Makarem

12. NERVES SUPERIOR GLUTEAL • Course: • passes through GSF, above piriformis, then between gluteus medius & minimus • Branches: • Muscular to gluteus medius, minimus & tensor fasciae latae • Articular to hip joint INFERIOR GLUTERAL • Course: • passes through GSF, below piriformis, then deep to gluteus maximus • Branches: • muscular to gluteus maximus NERVE TO QUADRATUS FEMORIS • Course: • passes through GSF, below piriformis • Branches: • Muscular to quadratus femoris & inferior gemillus • Articular to hip joint Prof. Saeed Abuel Makarem

13. NERVES Posterior cutaneous nerve of the thigh • Course: • passes through GSF, below piriformis, then descends deep to deep fascia • Branches: • cutaneous branches to: gluteal region, back of scrotum (labium majus) back of thigh & upper part of back of leg. Prof. Saeed Abuel Makarem

14. SCIATIC • Course: • passes through GSF, below piriformis, • then superficial to: ischial spine, • superior gemillus, tendon of obturator internus, • inferior gemillus, quadratus femoris & • adductor magnus • Branches: • no branches in gluteal region, • It divides into tibial & common peroneal nerves, in the middle of back of thigh Prof. Saeed Abuel Makarem

15. NERVES NERVE TO OBTURATOR INTERNUS • Course: • passes through GSF, below piriformis, then crosses the base of ischial spine & passes through LSF • Branches: • muscular to obturator internus & superior gemillus PUDENDAL • Course: • passes through GSF, below piriformis, then crosses the sacrospinous ligament & passes through LSF • Branches: • no branches in gluteal region Prof. Saeed Abuel Makarem

16. ARTERIES SUPERIOR GLUTEAL • Course: • passes through GSF, above piriformis, • then divides into superficial branch between gluteus maximus & medius and deep branch between gluteus medius & minimus INFERIOR GLUTEAL • Course: • passes through GSF, below piriformis, then deep to gluteus maximus with the inferior gluteal nerve • Branches of superior & inferior gluteal: muscular branches & articular branches to hip hoint INTERNAL PUDENDAL • Course: • passes through GSF, below piriformis, then crosses the tip of ischial spine & passes through LSF • Branches: no branches in gluteal region Prof. Saeed Abuel Makarem

17. IMPORTANT ANASTOMOSES IN THE THIGH • These are collateral anastomosis between the internal & external iliac arteries. • They are of great importance, when the femoral artery is obstructed above the origin of the profunda femoris artery. Prof. Saeed Abuel Makarem

18. IMPORTANT ANASTOMOSES TROCHANTERIC ANASTOMOSIS • Site: • in the region of trochanteric fossa • Importance: • main supply for neck & head of femur • Constituents: • Superior gluteal • Inferior gluteal • Medial circumflex femoral Prof. Saeed Abuel Makarem

19. CRUCIATE ANASTOMOSIS Site: at the upper border of adductor magnus (at level of lesser trochanter, UPPER ART OF THE BACK OF THE THIGH) Constituents: Inferior gluteal MCF LCF 1st perforating Prof. Saeed Abuel Makarem

20. Greater Sciatic Foramen BOUNDARIES • Greater sciatic notch, • sacrotuberous & • sacrospinousligament & ischial spine STRUCTURES PASSING THROUGH IT • Piriformis • 2 structuresabove piriformis: superior gluteal nerve & vessels • 8 structuresbelow piriformis: inferior gluteal nerve & vessels, sciatic nerve, posterior cutaneous nerve of thigh, nerve to quadratus femoris, nerve to obturator internus, internal pudendal vessels, pudendal nerve Prof. Saeed Abuel Makarem

21. Lesser Sciatic Foramen BOUNDARIES • Body of ischium, sacrotuberous ligament & • sacrospinous ligament & ischial spine STRUCTURES PASSING THROUGH IT: Tendon of obturator internus, nerve to obturator internus, internal pudendal vessels, pudendal nerve Prof. Saeed Abuel Makarem

22. Prof. Saeed Abuel Makarem