A14 - Pelvis, sacroiliac joint

Question 1

Pelvis

1. ​Which bones are the pelvis composed of?
2. Draw the main divisions of the pelvis

Answer 1

• Consists of two hip bones,:
  
  • Ossa coxae, fusion of three different bones:
    
    • Os ilium (craniodorsal)
    • Os pubis (cranioventral)
    • Os ischium (caudoventral)
  • Symphysis pelvis, junction line where the two coxal bones are united ventrally, divided into:
    
    • Symphysis pubica (cranial)
    • Symphysis ischiadica (caudal)

Question 2

Pelvis

Define the borders of the pelvis

Answer 2

• The bony pelvis is a broad ring around the pelvic cavity
• Roof of pelvis:
  
  • Sacrum
  • First few caudal vertebrae
• Floor of pelvis (soleum pelvis osseum):
  
  • ​Os pubis
  • Os ischiadicum
• Lateral walls:
  
  • Os ilium
  • Os ischium
• Apertura pelvis cranialis:
  
  • Bounded by linea terminalis
• Apertura pelvis caudalis:
  
  • Dorsally: 3-4 first caudal vertebrae
  • Ventrally: arcus ischiadicus and tuberositas ischiadicus
  • Lateral: Lig. sacrotumerale (latum)

Question 3

Pelvis

Give the structures of os coxae

Answer 3

• Hip bone
• Composed of:
  
  • Ilium
  • Ischium
  • Pubis

Structures:

• Acetabulum
  
  • Margo acetabuli
  • Fossa acetabuli
  • Incisura acetabuli
  • Facies lunata
    
    • Pars major (bo)
    • Pars minor (bo)
• Spina ischiadica
• Foramen obturatum
• Symphysis pelvis

Se egene notater for definisjoner

Question 4

Pelvis

Os ilium

Answer 4

• Ala ossis ili
  
  • ​The position of the wing differs:
    
    • Eq, ox: horizontal → fascies glutea is directed dorsally
    • Sus, ca: vertical → fascies glutea is directed lateral
  • The cranial border of the wing
    
    • Eq, ru: crista iliaca (sharp, concave)
    • Ca, sus: covex, thick
• Tuber sacrale
  
  • ​Ca: tuber is divided by a shallow nothch
    
    • Spina iliaca dorsalis cranialis (ca)
    • Spina iliaca dorsalis caudalis (ca)
• Fascies glutea
  
  • ​For attachment of gluteal muscles
• Fascies sacropelvina
  
  • ​Inner surface of the wing

Structures:

• Corpus ossis ilii
  
  • Area lateralis m. recti femoris
  • Area medialis m. recti femoris
  • Spina iliaca ventralis caudalis (ca)
• Ala ossis ilii Crista iliaca
  
  • Tuber coxae
    
    • Spina iliaca ventralis cranialis (ca)
    • Spina alaris (ca)
  • Tuber sacrale
    
    • Spina iliaca dorsalis cranialis (ca)
    • Spina iliaca dorsalis caudalis (ca)
  • Facies glutea
    
    • Linea glutea
  • Facies sacropelvina
    
    • Facies iliaca
    • Facies auricularis
    • Tuberositas iliaca
• Linea arcuata
  
  • Tuberculum m. psoas minoris (Ø ca)
• Incisura ischiadica major

Question 5

Pelvis

Os ischii

Answer 5

• Corpus ossis ischii: participating in forming acetabulum
• Symphysis ischiadica: the two sides unite
• Tuber ischiadicum
  
  • ​Eq, ca: thickened ridge
  • Ru: triangular
  • Sus: caudally directed process with a lateral tubercle
• Arcus ischiadicus: between tuber ischiadicum, caudal
  
  • The arch is deeper in female than male

Structures:

• Corpus ossis ischii
• Tabula ossis ischii
• Ramus ossis ischii
• Tuber ischiadicum
• Incisura ischiadica minor

Question 6

Pelvis

Os pubis

Answer 6

• Consists of three parts:
  
  • Corpus ossis pubis
  • Ramus cranialis ossis pubis: Cranial to for. obturatorium)
  • Ramus caudalis ossis pubis: Medial to for. obturatorium, fuses caudally with ramus ossis ischii)
• Symphysis pubis: Unite with the ramus of the opposite side
• Pecten ossis pubis: Cranial border of ramus cranialis
• Eminentia iliopubica: laterally on pecten ossis pubis
• Tuberculum pubicum ventrale: In the middle, formed by the two os pubis
• Tuberculum pubicum dorsale/ventrale
  
  • ​Male: crest
  • Female: more or less flat

Structures:

• Corpus ossis pubis
• Ramus cranialis ossis pubis
• Ramus caudalis ossis pubis
• Pecten ossis pubis
• Eminentia iliopubica
• Tuberculum pubicum dorsale
• Tuberculum pubicum ventrale
• Sulcus obturatorius
• Sulcus ligamenti accessorii ossis femoris (eq)

Question 7

Pelvis

Acetabulum

Answer 7

• The three pelvic bone unite to form the acetabulum
• Where the pelvis and the femur meets
  
  • ​**Art. coxae, hip joint
• Facies lunata: ​Articular part
  
  • Bo:
    
    • Pars major
    • Pars minor
• Fossa acetabuli: Non-articular fossa (for ligamentous attachment)​
• Incisura acetabuli: Passage of ligaments
• Margo acetabuli: Acetabular rim

Question 8

Pelvis

Give the interspecies differences

Answer 8

Os coxae

• Acetabulum
  
  • Facies lunata​
    
    • Pars major (bo)
    • Pars minor (bo)

Os ilium

• Ala ossis ilii
  
  • Spina alaris (ca)
  • Tuber coxae
    
    • Spina iliaca ventralis caudalis (ca)
    • Spina iliaca ventralis cranialis (ca)
  • Tuber sacrale
    
    • Spina iliaca dorsalis cranialis (ca)
    • Spina iliaca dorsalis caudalis (ca)
• Linea arcurata
  
  • Tuberculum m. psoas minoris (ø ca)

Os pubis

• Sulcus ligamenti accessorii ossis femoris (eq)
• Tuberculum pubicul dorsale (male)

Pelvis:

• Crista symphysialis (bo)
• Flat solum (eq)
• Deep arcus ischiadicus (ru)

Shape of the pelvic floor:

• Ru: deeply concave
• Ca: concave (but shallower than in ru)
• Eq: flat and vertical

Question 9

Pelvis

Draw the pelvis from dorsal and ventral view (eq)

Answer 9

Question 10

Sacroiliac joint

1. Type of joint
2. Ligaments
3. Draw

Answer 10

• Amphiarthrosis
• Plane joint (monoaxial)
  
  • ​Movement: slightly movable joint
• They form the pelvic ring
• Between facies auricularis of sacrum → facies auricularis of ilium (on facies sacropelvina)

Ligaments of art. membri pelvini

1. Membrana obturatoria (eq)
   
   • Close to for. obturatorium
2. Lig. sacrotuberale (ca)
   
   • Os sacrum and 1^st caudal vertebrae → tuber ischiadicum
3. Lig. sacrotuberale latum (un)
   
   • Os sacrum and 1^st caudal vertebrae → spina ischiadica and tuber ischiadicum
4. For. ischiadicum majus (un)
   
   • Between i**nc. ischiadica major, os scarum and lig. sacrotuberale latum
5. For. ischiadicum minus (eq)
   
   • Incisura ischiadica minor → lig. sacrotuberale (un: lig. sacrotuberale latum)

Ligaments of art. sacroiliaca:

1. Ligg. sacroiliaca v​entralia
   
   • ​Surrounding joint capsule
   • Ala sacralis → ilium
2. Ligg. sacroiliaca interossea
   
   • ​Surrounding joint capsule
   • Tuberositas sacralis → tuberositas iliaca
3. ​Ligg. sacroiliaca dorsalia
   
   • Sacrum → ilium
4. Lig. sacrotuberale (ø fe)

Symphysis pelvina:

• Symphysis pubica
• Symphysis ischiadica