Lecture 5: The Gluteal Region 2024 PDF

Lecture 5: The Gluteal region  Outline A bit of revision. Bones, joints, attachments and foramina of the gluteal region. The motions of the hip joint. Muscles, – Gluteals, – External rotators. The nerves & vascular structures. The clinical significance of the region...

Lecture 5: The Gluteal region  Outline A bit of revision. Bones, joints, attachments and foramina of the gluteal region. The motions of the hip joint. Muscles, – Gluteals, – External rotators. The nerves & vascular structures. The clinical significance of the region. Summary. Some questions for you Name the muscles of the medial fascial compartment of the thigh. What is the main motion associated with these muscles? What is the main artery supplying the region? What is the main nerve supplying the region?  Aims To study: – The bones, joints, attachments and foramina of the region. – The motions available at the hip joint. – The arrangement and functions of the gluteal and external rotator muscles. – The nerve and blood supply to the gluteal muscles, external rotators and hip joint. – Introduce the clinical importance of the region.  Bones Lumbar 5th lumbar vertebra spine Sacrum ‘Pelvis’ Hip joint – Ilium – Ischium – Pubis Femur  The sacroiliac joint Articulation of the sacrum to the pelvis. Limited motion Synovial Cartilaginous  Sacroiliac joint 2 Held together by powerful ligaments Directly by: – Anterior sacroiliac (relatively weak and thin, thickening of the joint capsule) – Posterior sacroiliac (stronger, divided in to long and short) – Interosseous (strongest)  Sacroiliac joint 3 SI joint further stabilised by: – Sacrospinous ligament Sacrum to Ischial spine – Sacrotuberous ligament Sacrum ischial tuberosity  Sacroiliac joint 4 Anterior sacroiliac ligament Short posterior sacroiliac ligament Long posterior sacroiliac ligament Sacrospinous ligament Sacrospinous ligament Sacrotuberous ligament Sacroiliac joint 5  Pubic symphisis Articulation between R & L pubic bones. Fibrocartilage joint (synchondrosis) assisted by ligaments  Foramina of the gluteal region Obturator Greater sciatic Lesser sciatic Greater sciatic foramen Gap formed by greater sciatic notch and sacrotuberous / spinous ligaments. Exit from pelvis to gluteal region.  Lesser sciatic foramen Gap formed by lesser sciatic notch and sacrotuberous / spinous ligaments. Exit from gluteal region to perineum Things passing through the sciatic foramina  Obturator foramen Covered by obturator membrane – Point of origin for obturator internus and externus. Obturator canal allows passage of obturator nerve and vessels  A bit more hip Motions – Sagittal plane Extension / flexion – Frontal plane ABduction / ADduction  A bit more hip 2 Transverse plane – Internal / external rotation. – (medial / lateral) Also: – Circumduction Movement in all 3 planes.  Hip problems Fracture / Dislocation – Consequnces OA DDH etc. Bursitis  Muscles Basically 2 groups – Gluteals – External rotators  Gluteus maximus Origin:Posterior surface of the ilium and sacrum. Sacrotuberous ligament Insertion: Gluteal tuberosity of the femur. Iliotibial tract. Action: Hip extension & external rotation. Stabilises pelvis and knee. Antagonists: Hip flexors Innervation: Inferior gluteal; L5, S1, S2  Gluteus medius Origin: Ilium between ant and post gluteal lines. Insertion: Lat surface of great trochanter. Action: ABduction and internal rotation of thigh at hip. Antagonists: ADductors and external rotators. Innervation: Superior gluteal; L4,L5, S1.  Gluteus minimus Origin: Ilium between ant & inf gluteal lines. Insertion: Ant surface of great trochanter. Action: ABduction & int rotation of thigh at hip. Antagonists: Adductors, external rotators. Innervation: Superior gluteal; L4,L5, S1.  Trendelenburg sign Gluteus medius and minimus should be strong enough to hold pelvis stable in single leg stance. If weak, pelvis will sag to unsupported side Often caused by nerve damage (superior gluteal)  The external rotators Piriformis The gemelli Quadratus femoris Obturator internus Obturator externus  Piriformis Origin: Middle 3 parts of sacrum. Insertion: Upper border of Gr trochanter. Action:ABduction & external rotation of thigh at hip. Antagonists: ADuctors, internal rotators. Innervation: Branches from L5, S1, S2.  Quadratus Femoris Origin: Upper, outer ischial tuberosity. Insertion: quadrate tubercle of intertrochanteric crest. Action: External rotation of hip and stabilisation. Antagonists: Internal rotators. Quadratus Innervation: Nerve femoris from L4, L5, S1.  Obturator internus Origin: Obturator membrane and surrounding bones. Insertion: Gr trochanter, above in front of trochanteric fossa. Action: external rotation and stabilisation of hip. Antagonists: internal rotators. Obturator Innervation: Nerve internus from L5, S1, S2.  The gemelli Origins: – Superior: Ischial spine. – Inferior: Ischial tuberosity. Insertion: with obturator internus. Action: Assists obturator internus. Antagonists: Internal rotators. Innervation: – S: Obturator internus The Gemelli: sit – I: Quadratus femoris either side of Ob. Internus tendon.  Obturator externus Origin: External surface of obturator membrane and ischiopubic ramus. Insertion: trochanteric fossa Action: External rotation of thigh. Antagonists: Internal rotators. Innervation: Obturator; L3, L4.  Nerves Nerves of the gluteal region arise from both the sacral and lumbar plexi. Due to proximity of muscles of the region to the lumbar and sacral plexi many of the muscles have their own nerves rather than being innervated by a branch of a larger nerve. Sensory (cutaneous) nerves also arise from lumbar and sacral plexi.  Nerves 2 (motor) Superior gluteal Quadratus femoris nerve. (L4, L5, S1) nerve. (L4, L5, S1) – Gluteus medius – Quadratus femoris – Gluteus minimus – Gemellus inferior – Tensor fascia lata Inferior gluteal Piriformis nerve nerve. (L5, S1, S2) – S1, S2 – Gluteus maximus Obturator Obturator internus externus nerve. (L5, S1, S2) – Obturator (posterior – Obturator internus branch) (L3, L4) – Gemellus superior Nerves 3 (motor)  Nerves 4 (motor) Pudendal – Supplies the ‘naughty bits.’ Sciatic – V. important but just arises and passes through gluteal region doesn’t innervate any muscles here. – Innervates posterior thigh, lower leg and foot (more later)  Nerves 5 (sensory) Subcostal Iliohypogastric Lumbar 1 - 3 Sacral posterior rami Perforating cutaneous Posterior femoral cutaneous A bit of lateral femoral cutaneous  Nerves 6 (hip joint) Hip joint may be supplied by branches from: – Femoral nerve – Obturator nerve (and / or accessory obturator) – Nerve to quadratus femoris – Superior gluteal – Sciatic  Nerves 7 The sciatic nerve  Nerves 8 More sciatic nerve  Nerves 9 Sciatic variations  Nerves 10 Safe injection site  Vascular structures Superior gluteal artery Inferior gluteal artery – Both of the above are branches of the internal iliac artery and pass through the greater sciatic foramen. Also: – Trochanteric anastomosis – Cruciate anastomosis Vascular structures 2  Vascular structures 3 (Hip joint) Head of femur supplied by posterior branch of obturator artery (intracapsular). Might also be supplied by medial circumflex femoral artery. Remainder of hip joint supplied by medial and lateral circumflex femoral arteries. (extracapsular) Vascular structures 4 Hip joint Motion at the hip joint Approx. 40° Approx. 25° abduction adduction Motion at the hip joint Approx. 120° Approx. 30° Flexion Extension (gait: 30° required) (gait: 10° required) Motion at the hip joint Approx. 45° internal And external rotation (15-20° rotation Required in gait)  Hip joint: ilium, ischium, pubis ligamentous support – pubo-femoral ligament Relatively weak – ilio-femoral ligament Anterior aspect of hip joint – ischiofemoral ligament Strong Posterior aspect of hip joint fibrous capsule HJ capsule Pubofemoral ligt. Iliofemoral ligt. Ischiofemoral ligt.  Arterial supply to the HJ extracapsular arterial ring at the base of the femoral neck (medial & lateral circumflex aa.) Ascending cervical aas.: give rise to subsynovial intra articular ring - artery of ligamentum teres (derived from obturator or medial circumflex aa.) – inadequate to supply femoral head with displaced fractures  Pelvic motion during gait hip takes part in major determinants of gait to allow smooth progression of the centre of mass Pelvic rotation – occurs in transverse plane – approximately 4 degrees (anterior and posterior) Pelvic list – occurs in the frontal plane – approximately 5 degrees (medial and lateral)  Summary You should now be able to: – Identify the gluteal muscles and external rotators and know their functions. – Identify the major nerves within the gluteal, what they innervate or cutaneous areas they serve. – Identify the major vascular structures and how the hip joint is supplied with blood. – Have a rudimentary understanding of the clinical significance of the area and the impact of some injuries / conditions.  Look forward For next week: – Read around general issues raised today – Muscle structure, location and function – Vascular structures and nerves Next week: – Lecture posterior thigh and knee.