The pelvic girdle (cingulum membri inferioris) consists of:

• sacrum (os sacrum)

• hip bone (os coxae)

The hip bone is formed by three fused bones:

• ilium (os ilium)

  

  • ischium (os ischii)

    

  • pubis (os pubis)

    

  These bones are connected by cartilage during childhood and only fuse together completely at the age of 13-17 years.

  The fusion point is the acetabulum (acetabulum), containing the lunate surface (facies lunata) for the femoral head (these bones are involved in the formation of the hip joint).

  The acetabulum has an acetabular notch (incisura acetabuli).

  

  

  The bottom of the acetabulum is called the acetabular fossa (fossa acetabuli).

  

  

  Moreover, the fossa is bounded by the acetabular margin (limbus acetabuli).

  

  Let us examine the structure of the ilium. It has two large parts:

  • body (corpus ossis ilii)

    

  • ala / wing (ala ossis ilii)

    

    The ala has two surfaces:

  • gluteal surface (facies glutea), which is located at the back

  • iliac fossa (fossa iliaca), which lies in front, slightly recessed

  • sacropelvic surface (facies sacropelvica)

    

    

    The superior border of the wing is thickened and is called the iliac crest (crista iliaca).

    

    There are three lines on the crest, to which the abdominal muscles are attached:

  • inner lip (labium internum)

    

  • intermediate zone (linea intermedia)

    

  • outer lip (labium externum)

    

    On the border of the front and middle third of the iliac crest lies the tuberbulum of the iliac crest (tuberculum iliacum).

    

    In the front, the iliac crest passes into the anterior superior iliac spine (spina iliaca anterior superior), and in the back, into the posterior superior iliac spine (spina iliaca posterior superior).

    

    

    Under those spines are the same inferior spines — anterior inferior iliac spine (spina iliaca anterior inferior) and the posterior inferior iliac spine (spina iliaca posterior inferior).

    

    

    There are three roughened lines on the external surface of the wing of the ilium, to which the following gluteal muscles are attached:

  • anterior gluteal line (linea glutea anterior)

    

  • posterior gluteal line (linea glutea posterior)

    

  • inferior gluteal line (linea glutea inferior)

  

  There is an arcuate line (linea arcuata) in the lower part of the iliac fossa, which adjoins the auricular surface (facies auricularis) in front. This surface together with the sacral surface forms the sacro-iliac joint.

  

  

  In addition, the arcuate line passes into the iliopubic eminence (eminentia iliopubica), where the ilium fuses with the pubis.

  Above the auricular surface is the iliac tuberosity (tuberositas iliaca).

  

  

  Dictionary

  Ilium

  pelvic girdle

  cingulum membri inferioris

  sacrum

  os sacrum

  hip bone

  os coxae

  ilium

  os ilium

  ischium

  os ischii

  pubis

  os pubis

  acetabulum

  acetabulum

  lunate surface

  facies lunata

  acetabular notch

  incisura acetabuli

  acetabular fossa

  fossa acetabuli

  acetabular margin

  limbus acetabuli

  body of ilium

  corpus ossis ilii

  ala of ilium

  ala ossis ilii

  gluteal surface

  facies glutea

  iliac fossa

  fossa iliaca

  sacropelvic surface

  facies sacropelvica

  iliac crest

  crista iliaca

  inner lip

  labium internum

  intermediate zone

  linea intermedia

  outer lip

  labium externum

  tuberculum of iliac crest

  tuberculum iliacum

  anterior superior iliac spine

  spina iliaca anterior superior

  posterior superioriliac spine

  spina iliaca posterior superior

  anterior inferior iliac spine

  spina iliaca anterior inferior

  posterior inferior iliac spine

  spina iliaca posterior inferior

  anterior gluteal line

  linea glutea anterior

  posterior gluteal line

  linea glutea posterior

  inferior gluteal line

  linea glutea inferior

  arcuate line

  linea arcuata

  auricular surface

  facies auricularis

  iliopubic eminence

  eminentia iliopubica

  iliac tuberosity

  tuberositas iliaca