Pathology of the hip bone

1. OSTEOLOGY OF
THE HIP BONE
RDG 301 PRESENTATION
GROUP 1

2. GROUP 1- MEMBERS
1. ADEWUYI ADEDPOSI OMOTOYE- LCU/UG/20/16411
2. AWA QUEEN OBOKO – LCU/UG/19/14817
3. FALEYE YETUNDE HELEN – LCU/UG/20/16214
4. GANIU RASHEEDAT EBUNOLUWA – LCU/UG/19/15859
5. LEWIS ABIMBOLA – LCU/UG/20/16755
6. MECCA ABDULLAHI ADEMOLA – LCU/UG/19/15361
7. OJUMU AKINDELE OLUSEYI- LCU/UG/20/17845
8. OLUWANIYI VINCENT KEHINDE – LCU/UG/20/16626
9. OMOIGBERALE THANKGOD. E – LCU/UG/20/17861
10. OMOTOSHO ANJOLAOLUWA .R- LCU/UG/20/16986
11. OSUNRO OLUDARE JOHNSON – LCU/UG/20/16610

3. OUTLINE
 INTRODUCTION
 COMPOSITION OF THE HIP BONE
 BONY LANDMARK
 BLOOD SUPPLY
 INNERVATION OF THE HIP JOINT
 MOVEMENT AT THE HIP JOINT
 Radiologic importance
 Applied radiology

4. INTRODUCTION
 The hip joint is a ball and socket type of synovial joint that connects the pelvic
girdle to the lower limb. In this joint, the head of the femur articulates with
the acetabulum of the pelvic (hip) bone.
 The hip joint is a multiaxial joint and permits a wide range of motions.
 Compared to the glenohumeral (shoulder) joint, however, this joint sacrifices
mobility for stability as it is designed for weight bearing.
 The entire weight of the upper body is transmitted through this joint to the lower
limbs during standing.
 The hip joint is the most stable joint in the human body.

5. COMPOSITION OF THE HIP BONE
The hip bone is comprised of the three parts;
 the ilium,
 pubis and
 ischium.
Prior to puberty, the triradiate cartilage separates these parts – and fusion only begins at
the age of 15-17.
Together, the ilium, pubis and ischium form a cup-shaped socket known as the
acetabulum (literal meaning in Latin is ‘vinegar cup‘). The head of the femur articulates
with the acetabulum to form the hip joint.

6. The Hip Bone
The left and right hip bones (innominate bones, pelvic bones) are two irregularly shaped bones
that form part of the pelvic girdle – the bony structure that attaches the axial skeleton to the
lower limbs.
The hip bones have three main articulations:
 Sacroiliac joint – articulation with the sacrum.
 Pubic symphysis – articulation between the left and right hip bones.
 Hip joint – articulation with the head of femur.

7. Overview of the anatomical position of
the hip bones

8. BONY LANDMARKS OF THE HIP JOINT

9. Parts of the Hip Bone
This diagram shows the hip bone of a 5 year old, with
triradiate cartilage still present.

10. The Ilium
The ilium is the widest and largest of the three parts of the hip bone, and is located
superiorly. The body of the ilium forms the superior part of the acetabulum (acetabular roof).
Immediately above the acetabulum, the ilium expands to form the wing (or ala).
The wing of the ilium has two surfaces:
 Inner surface – has a concave shape, which produces the iliac fossa (site of origin of the
iliacus muscle).
 External surface (gluteal surface) – has a convex shape and provides attachments to the
gluteal muscles.
 The superior margin of the wing is thickened, forming the iliac crest. It extends from the
anterior superior iliac spine (ASIS) to the posterior superior iliac spine (PSIS).
 On the posterior aspect of the ilium there is an indentation known as the greater sciatic
notch.

11. The Bony Landmarks of the Ilium
td (2021)

12. Clinical Relevance: Anterior Superior
Iliac Spine (ASIS)
o The anterior superior iliac spine (ASIS) is an important anatomical landmark:
• Mid-inguinal point – halfway between the ASIS and the centre of the pubic
symphysis. The femoral artery can be palpated here.
• Mid-point of the inguinal ligament – halfway between the ASIS and the pubic
tubercle.
o In clinical practice, a patient’s “true” leg length is measured from the ASIS to the
medial malleolus at the ankle joint. This is distinct from “apparent” leg length, which
is measured from the umbilicus to the medial malleolus.
o True leg length discrepancy is a feature of various hip disorders, as well as being a
potential complication of hip joint replacement (arthroplasty).

13. The Pubis
 The pubis is the most anterior portion of the hip bone. It consists of a body, superior
ramus and inferior ramus (ramus = branch).
 Pubic body – located medially, it articulates with the opposite pubic body at the pubic
symphysis. Its superior aspect is marked by a rounded thickening (the pubic crest),
which extends laterally as the pubic tubercle.
 Superior pubic ramus – extends laterally from the body to form part of the
acetabulum.
 Inferior pubic ramus – projects towards the ischium.
 Together, the superior and inferior rami enclose part of the obturator foramen –
through which the obturator nerve, artery and vein pass through to reach the lower
limb.

14. Bony Structure of the Pubis

15. Orientation of the hip bones within the
pelvis

16. Clinical Relevance: Pubic Rami fractures
 Pubic rami fractures can sometimes be observed on x-rays in elderly patients who are
investigated after simple low energy falls from standing height. In this context and
provided they are the only injury a patient has sustained, these fractures are usually
treated without surgery.
 Healing can be expected within 6-8 weeks and patients are encouraged to fully weight
bear straightaway

17. The Ischium
The ischium forms the posteroinferior part of the hip bone. Much like the
pubis, it is composed of a body, an inferior ramus and superior ramus.
 The inferior ischial ramus combines with the inferior pubic ramus forming
the ischiopubic ramus, which encloses part of the obturator foramen.
 The posteroinferior aspect of the ischium forms the ischial tuberosities and
when sitting, it is these tuberosities on which our body weight falls.
Near the junction of the superior ramus and body is a posteromedial
projection of bone; the ischial spine.
Two important ligaments attach to the ischium:
Sacrospinous ligament – runs from the ischial spine to the sacrum, thus
creating the greater sciatic foramen through which lower limb neurovasculature
(including the sciatic nerve) transcends.
Sacrotuberous ligament – runs from the sacrum to the ischial tuberosity,
forming the lesser sciatic foramen.

18. Bony landmarks of the ischium

19. INNERVATION
 The hip joint is innervated by the articular branches of multiple nerves that emerge
from the lumbosacral plexus (L2-S1). The nerve supply to a specific region of the joint
typically corresponds to the innervation of the muscle that crosses it:
• The femoral nerve innervates the anterior aspect
• The obturator nerve supplies the inferior aspect
• The superior gluteal nerve supplies the superior aspect
• The nerve to the quadratus femoris innervates the posterior aspect.
 It is important to note that pain sensations from the vertebral column can be referred
to the hip joint, while primary hip pain may be referred to the knee as they share
similar innervation.

20. Motion At the Hip Joint
MOVEMENT MUSCLES INVOLVED
Flexion Psoas major, iliacus and rectus femoris; assisted by pectineus, tensor
fasciae latae and sartorius
Extension Gluteus maximus, biceps femoris, semitendinosus,
semimembranosus and adductor magnus
Abduction Glutei medius and minimus; assisted by tensor fasciae latae, piriformis
and sartorius
Adduction Adductors longus, brevis and magnus, gracilis; assisted by pectineus,
quadratus femoris and the inferior fibres of gluteus maximus
Internal rotation Glutei minimus and medius; assisted by tensor fasciae latae and most
adductor muscles
External rotation Gluteus maximus, obturator internus, superior and inferior gemelli,
quadratus femoris, piriformis; assisted by obturator externus and
sartorius
Mnemonic: Patched Goods Often Go On Quilts (PGOGOQ)
(Piriformis, Gemellus superior, Obturator internus, Gemellus inferior,
Obturator externus, Quadratus femoris)

21. BLOOD SUPPLY
 The blood supply of the hip joint is from the medial and lateral circumflex femoral
arteries (branches of the deep artery of the thigh), the obturator artery and
the superior and inferior gluteal arteries. Together, these arteries form a periarticular
anastomosis around the hip joint. This anastomotic network gives rise to
the retinacular arteries which supply the greatest volume of blood to the head and
neck of the femur. Additionally, the obturator artery gives rise to the artery of the head
of the femur within the ligament of the head of the femur.

22. Clinical Relevance: Pelvic fractures
 There are two broad groups of pelvic fractures:
 Low energy injuries:
For example, a simple fall from standing height in an osteoporotic patient resulting in pubic rami
fracture.
These are usually ‘stable’ injuries, not requiring surgery.
 High energy injuries with direct or transmitted trauma:
For example, after a high speed road tra ic accident. These result in more extensive fractures
which may include the acetabulum and sacroiliac joint.
These can be ‘unstable’ injuries and may require urgent surgery.
Higher energy injuries can be associated with soft tissue and vascular injury. In particular, the
bladder and urethra are at high risk of damage. Vascular injury can result in life threatening
haemorrhage.
 In the context of a high energy major trauma patient, the pelvis can be a major source of
bleeding due to fracture. As a result, major trauma patients are assumed to have a pelvic
fracture until proven otherwise and a ‘pelvic binder’ is used to stabilise the pelvis and
minimise further bleeding. Circumferential pressure is applied by the binder at the level of
the greater trochanters – an important anatomical landmark.

23. APPLIED ANATOMY
 Anatomical variants
• synovial herniation pits (Pitt pits)
• os acetabuli
• communication between the iliopsoas bursa and the hip joint 5
• accessory iliacus tendon
• congenital absence of the ligamentum teres 5
• hip plicae
• pectinofoveal fold
• supra-acetabular fossa
• accessory superior acetabular notch

24. APPLIED ANATOMY (Cont’d)
 Related pathology
• gamuts
• acetabular protrusion
• coxa profunda
• coxa magna
• coxa plana
• coxa vara
• coxa valga
• fovea alta

25. APPLIED ANATOMY (Cont’d)
• traumatic
• femoro-acetabular impingement
• hip dislocation
• anterior dislocation
• posterior dislocation
• femoral head fracture
• acetabular fracture
• neck of femur fracture
• labral tear

26. APPLIED ANATOMY (Cont’d)
• degenerative
• osteoarthritis
• inflammatory
• transient synovitis of the hip
• others
• developmental dysplasia of the hip
• slipped upper femoral epiphysis
• Perthes disease
• trochanteric syndrome

27. HIP RADIOGRAPH

28. FRACTURE
X-Ray demonstrating an acetabular fracture

29. References
 https://teachmeanatomy.info/pelvis/bones/
 https://www.kenhub.com/en/library/anatomy/arthrology
 https://radiopaedia.org/articles/hip-joint-1
 Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy
(7th ed.). Philadelphia, PA: Lippincott Williams & Wilkins.
 Netter, F. (2019). Atlas of Human Anatomy (7th ed.). Philadelphia, PA:
Saunders.