hip and pelvis

• Innominate Bone


  Also known as: Coxal Bone, OS Coxae
• Innominate Bone

  Composed of: Ilium + pubis + ischium (bounded by triradiate ligament)
• Ilium

  • Largest part of the innominate bone (Anterosuperior)
• Pubis

  • Smallest part of the innominate bone (Anteroinferior)
• Functions of the Pelvis

  • Transmits weight of the body from the vertebral column to the lower extremity
  • Contains and supports organs
  • Attaches lower extremity to the axial skeleton
  • Attachment of trunk and lower extremity muscles
• Formation of the Acetabulum

  1. 40% Ilium

  2. 40% Ischium

  3. 20% Pubis
• Acetabulum

  Ossifies by 20-25 years old by the Triradiate Cartilage / Ypsiloformis Ligament
• Iliac Crest


  • Highest point, L4 level, Attachment of the Tensor Fascia Latae
• ASIS

  Attachment of the longest muscle of the body "Tailor's Muscle"
• Inguinal Ligament


  Also known as Poupart's Ligament (ASIS to Pubic Tubercle)
• AIIS


  • Attachment site of the Straight Head of the Rectus Femoris
  • Ligament: Iliofemoral Ligament
• PSIS


  • Dimple of Venus, S2 level, Middle of SI joint
• Iliac Tubercle


  • 2 inches above ASIS and 2 inches below iliac crest, Level: L5, Origin of: ITB
• Iliac Fossa


  • Attachment of Illacus Muscle
• Greater Sciatic Notch


  • Part of the Ilium
• Lesser Sciatic Notch


  • Part of the Ischium
• Greater Sciatic Foramen


  Contents: Superior: Sup. Gluteal N., Sup. Gluteal Arteries and Veins<|>Inferior: Sciatic N., Post. Cut. N. of the thigh, Pudendal N., Inf. Gluteal N., artery and veins, Internal Pudendal artery and veins, N. to obturator Infernus, N. to Quadratus Femoris
• Fat Wallet Syndrome


  Piriformis Syndrome
• Lesser Sciatic Foramen


  • Exit of gluteal region to the perineum
  • Contents: Internal Pudendal Artery and Vein, Pudendal Nerve, N. to Obturator Internus, N. to quadratus Femoris, Tendon in Obturator Internus
• Ischial Tuberosity


  • Also known as Sit Bone, MC site of pressure ulcer, Mm Attachments: Hamstrings (except short head of biceps fem.), Gemmelus Inferior and Quadratus Femoris
• Ischial Spine


  • Mm Attachment: Gemmelus Superior
  • Ligament: Sacrospinous Ligament
• Ischial Ramus


  • Mm Attachment: Adductor Magnus
  • Originating Muscles: Garcilis, Obturator Internus and Externus
• Pubis

  • Contains the 5 major adductors: Pectineus (Sup.), Adductor Longus (Body), Adductor Magnus (Inf.), Gracilis (Inf.), Adductor Brevis (Inf.)
• Sacrum


  • 5 fused vertebra, Sacral canal, Sacral Promontory, Lateral Mass / ala, Ant. And post. Sacral foramina, Lat. And med. Sacral crest, Mm anterior: Piriformis, Mm posterior: G-max
• Coccyx


  • 4 fused vertebrae, Tail Bone
• Pelvic Inlet

  Formed by the symphysis pubis, iliopectineal line and sacral promontory, Divides pelvis into true and false pelvis
• Pelvic Outlet


  Formed by coccyx posteriorly, ischial tuberosity laterally and pubic arch anteriorly, Contains mm of the pelvic floor, Separates pelvic cavity from perenium
• True Pelvis


  Lower portion (contains organs for reproduction)
• False Pelvis


  Superior portion (contains abdominal cavity)
• Boundaries of the Pelvis

  • Anterior: Lower Abdominal Wall
  • Lateral: Iliac Fossa + Iliacus
  • Posterior: Lumbar Vertebra
• Differences between Female and Male Pelvis

  • False Pelvis: Female - Shallow, Male - Deeper
  • Pelvic Inlet: Female - Oval, Male - Heart Shape
  • Pelvic Outlet: Female - Larger, Male - Smaller
  • Pubic Arch: Female - Round > 90 deg, Male - Narrow < 90 deg
  • Sacrum: Female - Wider & Shorter, Male - Longer, Narrower and more prominent
• Types of Female Pelvis

  • Gynecoid – Typical
  • Android – Funnel shaped
  • Anthropoid – Long, narrow oval shape
  • Platypeloid – Wide pelvis, flattened at the brim
• Acetabulum


  • Forms ½ sphere "vinegar cup), Deeper (more stable), Content: Ligamentum Teres, Fat Pad, Synovial Membrane and Synovial Fluid
• Ligamentum Teres


  Conduit of blood vessel supplying the femoral head
• Acetabulum: Parts

  • A. Lunate – articulating surface of the acetabulum
  • B. Acetabular Fossa – non-articulating portion. Reservoir of synovial fluid and for proprioception
  • C. Acetabular Labrum aka Cotyloid Ligament – Deepens the joint
• Femur

  • Largest, longest and heaviest
  • Femoral Head Orientation: SAP
  • Fovea Capitis: Ligamentum Teres
  • Femoral Neck: MC site of fracture in Femur
• Red Carpet Muscles

  • Piriformis
  • Obturator Internus
  • Obturator Externus
  • Gemellus Superior
  • Gemellus Inferior
  • Quadratus Femoris
• Normal Angle of Inclination

  125 degrees
• Sacroiliac Joint

  Di-arthrodial joint, Moving but no muscles is involved
• Sacroiliac Joint Movements

  1. Nutation: Iliac crest approximates, Ischial tuberosities move apart, Inlet: Smaller, Outlet: Larger, Sacral promontory moves anteroinferior, Coccyx moves superiorly

  2. Counternutation: Iliac crest moves apart, Ischial tuberosities approximates, Inlet: Larger, Outlet: Smaller, Sacral Promontory moves posterosuperior, Coccyx moves inferiorly