Skeletal System

2

Axial Skeleton

• 80 bones

3

Appendicular Skeleton

• 126 bones

4

Bony composition

5

Endochondral Ossification

Diaphysis: refers to the shaft portion of the long bones. Primary site of ossification.

Epiphysis: expanded end portion and it’s the secondary site of ossification.

Metaphysis: growth zone between the epiphysis and diaphysis.

Congenital and Hereditary Diseases

7

Osteogenesis Imperfecta1. Often called brittle bone

disease

2. Hereditary or congenital1. Serious disease

3. Bone cortex is thin and porous, and trabeculae are thin, delicate and widely separated

4. X-ray demonstrates various fractures in various stages of healing and general decrease in bone mass

8

Osteogeneis Imperfecta

9

Achondroplasia1. Most common inherited

disorder of the skeletal system

2. Results in bone deformity & dwarfism1. Normal trunk size &

shortened extremities

2. Usually no more than 4ft tall

3. Clinical manifestation:1. Lumbar lordosis,

2. bowed legs,

3. bulky forehead with hypoplasia

4. narrowing of foramen magnum causing neural compression

10

Achondroplasia

11

Osteopetrosis1. Bones are abnormally heavy and compact but brittle

2. All bones are affected by most changes occur in long bones of extremities, vertebrae, pelvis and base of skull

3. X-rays demonstrate increase in thickness and density of bony cortex.

4. Increase in the # and size of trabeculae, reduction of the marrow space

12

Osteopetrosis

13

Scoliosis

1. Lateral curvature of the spine

2. Does not usually become visible until adolescents

3. Affects girl more

14

Scoliosis

15

Rotoscoliosis

16

Transitional VertebraOften called Lumbar Ribs

1. Takes on characteristics of both vertebrae on each side of a major division of the spine

2. 1st lumbar may have a rib

3. At C7 there may be a cervical rib

17

Cervical Ribs & Lumbar Ribs

18

Anencephaly

1. Congenital abnormality

2. Brain and cranial vault do not form

3. Results in death shortly after birth

4. Can be diagnosed with US before they are born

19

Anencephaly

Inflammatory Diseases

21

Rheumatoid Arthritis

1. Chronic autoimmune that may fluctuate in severity

2. Overgrowth of the synovial tissues

3. X-ray shows soft tissue swelling & osteoporosis of affected bone. Bone erosion & decalcification

22

Rheumatoid Arthritis

23

Osteoarthritis1. Most common form of

arthritis

2. Articular cartilage degenerates & gradually is worn away exposing underlying bone

3. Ostephytes & bone spurs are on x-rays

24

Osteoarthritis

25

Osteomyelitis1. Infection of the bone &

bone marrow

2. Symptoms & signs include fever, heat in the affected area, & dull pain

3. X-rays demonstrate loss of bone calcium and soft tissue swelling

26

Osteomyelitis

27

Ankylosing Spondylitis

1. Progressive form of arthritis affecting the spine

2. X-ray shows bilateral narrowing & fuzziness of the SI joints1. Calcification of the

bones of the spine with ossification of the vertebral ligaments

28

Ankylosing Spondylitis

29

Gout1. Is an inherited

metabolic disorder in which excessive amounts of uric acid is produced & deposited in the joint and adjacent bone

2. Bone changes include erosion & overhanging edges

30

Gout

31

Spondylolisthesis

1. Slipping of the body of the vertebra

2. Symptoms are similar to those of a herniated disk

32

Spondylolisthesis

33

Osteochondroma1. Benign bone tumor

2. Affects women more than men

3. Asymptomatic

4. Excessive bone growth

5. Cortex of osteochondroma blends in with normal bone and growth protrudes up & away from nearest joint

34

Osteochondroma

35

Osteosarcoma1. Most common

primary malignancy of the skeleton

2. Highly aggressive and most often occurs in the bone marrow

3. X-ray appears as a sunray or sunburst

36

Osteosarcoma

37

Bone Cyst

1. Idiopathitic disease and is not a true neoplasm

2. Consists of numerous blood filled arterivenous communications

3. Most common treatment is surgical removal

38

Bone Cyst

39

MRI1. Superior contrast resolution for soft tissue

detail1. Modality of choice for soft tissue tumor2. Extremely useful in eval of joints

2. MRi detects a larger number of musculoskeletal subtleties with higher resolution imaging

3. Bone marrow imaging is better than nuc med scans for subtle abnormalities

40

CT1. Can be performed quickly & noninvasively

2. Defines extent of fractures and dislocations

3. Superior to MRI for cortical bone and visualization of bony detail

4. Gives better bone detail than plain x-ray

5. Has been largely replaced by MRI for soft tissue

41

Nuclear Medicine

1. Has advantage over CT & MRI because it can scan the whole body at one time

2. Can show if an injury is old or new

3. Still the standard for examination of metastatic processes because it demonstrates metabolic reaction of bone to the disease process1. Is more sensitive than comparative radiographic

studies