Anatomy of the hip joint

Question 1

What represents the pelvic girdle?

Answer 1

The hip bone

• Flat-irregular bone, that links the trunk skeleton and the lower limb skeleton

Question 2

What are the bones of the pelvic girdle?

Answer 2

1) Ilium

2) Ischium

3) Pubis

Question 3

What are the different structures of the ileum?

Answer 3

1) Iliac crest (landmark to identify L4)

2) Tubercle of the iliac crest (thickened part of the iliac crest)

3) Anterior superior iliac spine

4) Anterior inferior iliac spine

5) Posterior superior iliac spine

6) Posterior inferior iliac spine

• The four spines are palpable

7) Gluteal surface (where gluteal muscles arise from), there are three gluteal surfaces separated by gluteal lines

• Acetabulum (lunate surface “shared between the three bones of the hip bone”), where the femur will articulate, similar to the glenoid fossa but much deeper and more rounded, it is not a complete circle as the lower edge is open forming the acetabular notch, it also has an acetabular fossa which is non-articular in the middle

Question 4

What are the different structures found in the pubis?

Answer 4

• The pubis has a central large body and 2 rami
• 1 of the rami will articulate with the ileum and ischium called superior pubis ramus
• The other ramus will articulate with the ischium and is called the inferior pubic ramus

Question 5

Describe the different characteristics of the ischium

Answer 5

• Has a thick body
• The body has a posterior thickening called the Ischial tuberosity (the bone we sit on)
• At the superior part of the ischium there is a bony protrusion called the ischial spine
• Has one ramus called the ischial ramus which articulates with the inferior pubic ramus closing the obturator foramen, forming the pelvic/pubic ramus
• The joint between the ischial ramus and the pubic ramus articulates around the age of 7, so we should not mistaken it for a fracture on a X-ray

Question 6

What is the obturator foramen?

Answer 6

• Formed by the union of the pubis and ischium
• Vessels enter through the obturator canal
• Completely enclosed by the obturator membrane except in a small area above called the obturator canal

Question 7

What is the tri-radiate cartilage?

Answer 7

It is a cartilage found between the ischial and pubic ramus allowing its mobilization, is ossified at the age of 18

Question 8

What forms the obturator foramen?

Answer 8

Formed by the union of the pubis & ischium

• It is enclosed by an outer membrane named obturator membrane (except in a small area above the obturator canal

Question 9

Describe the structures found on the medial view of the ileum of the hip bone

Answer 9

1) Flat, Concave irregular, that does not give any attachments to muscles pelvic surface

2) Arcuate surface

3) Iliopubic eminence (a bony elevation between the pectinate and arcuate lines)

4) Sacral surface (articular, articulates with the sacrum forming the sacroiliac joint, forming one of the strongest joints in the boy)

5) Greater sciatic notch (above the ischial spine)

Question 9

Describe the structures found on the medial view of the pubic of the hip bone

Answer 9

1) Pectinate line (sharp edge attachment site of the pectineus muscle), continuous in the ileum as the arcuate line

2) Obturator canal

3) Superior pubic ramus

4) Sympheseal surface (articular, articulates with the pubis bone, forming a secondary cartilaginous joint “symphysis pubis”)

5) Inferior pubic ramus

Question 10

Describe the structures found on the medial view of the Ischium of the hip bone

Answer 10

1) Lesser sciatic notch (below the ischial spine)

Question 10

Describe the structure and characteristics of the femur

Answer 10

• The femur is the longest bone in the body followed by the tibia (they articulate in the knee joint)

1) The head of the humerus is completely rounded

2) Its neck is very long

3) It has two trochanters the greater trochanter and the lesser trochanter

4) Between the two trochanters is a bony ridge called the intertrochanteric line

5) In the midline of the head of the femur there is a depression called the fovea of the head, which gives the attachment to the ligament of the head of the femur

6) Posteriorly between the two trochanters there is a more prominent body structure called the intertrochanteric crest

7) Trochanteric fossa: a depression on the greater trochanter

8) Quadrate tubercle: lies in the middle of the intertrochanteric crest (origin of quadratus femoris muscle)

9) Calcar: an area in the intertrochanteric crest that has a lot of foramina and openings for the vascular supply

10) Linea aspera: A thick line in the back of the shaft that lies along the whole posterior surface of the femur, site for muscle and ligament attachment

11) Linea aspera will bifurcate into two lines pectinal line medially and goes to the lesser trochanter, & gluteal tuberosity which goes laterally to the greater trochanter giving an attachment to the gluteus Maximus muscle