Pathology - S2B3 - Bone - Bone 2

Front 1

Describe a Fracture after 2 days

Back 1

1. Blood Clot is formed
- good b/c blood has lots of Growth Factors to enhance repair & healing

2. At periphery & Endosteum, there is marked proliferation of Osteoblasts

3. There is no overt Callus formation (Callus = new bone)

Front 2

Describe a Fracture after 1 week

Back 2

1. Primary Callus forms at broken ends of bone

2. Outside is Cartilage & is a sign that repair is due to Endochondral formation = indirect bone formation from a "cartilage model"
3. Endosteum is usually linked by Callus, bone

Front 3

Describe Fractures month-years post fracture

Back 3

1. Osteoclasts dissolve the temporary bone & Osteoblasts lay new bone

2. The action of Osteoblasts maximally resist fracture at the same location; if you bend the bone it will rarely fracture in the same place

Front 4

Autosomal Dominant mutation in Fibroblast Growth Factor Receptor 3 (FGFR3) that causes impaired proliferation of Cartilage at the Growth Plate

Back 4

Achondroplasia

Front 5

Achondroplasia = bone is short but broad at the Epiphysis
-narrow Epiphyseal Plates & Bony sealing off of the area between the Epiphyseal Plate & Metaphysis

Back 5

What is this picture showing?

Front 6

Achondroplasia
-Growth Plate is disordered, cells are not in a regular array
-Activation of FGF#3 inhibits Cartilage synthesis at the Epiphyseal Growth Plate, resulting in decreased Endochondral Bone formation & premature ossification of Growth Plates

Back 6

What is seen here?

Front 7

Achondroplasia = mutation in FGFR3
-short & thick Long bones
-Cranial & vertebral bones are spared = relatively large head & trunk

Back 7

What is the cause?

Front 8

Autosomal dominant disease resulting in defective synthesis of Collagen type I & insufficient Bone Matrix synthesis

Back 8

Osteogenesis Imperfecta

Front 9

Pathogenesis: A reduction in Bone Matrix, which alouth fully calcified, results in fragile bones that are more prone to fracture

Back 9

Osteogenesis Imperfecta

Front 10

Osteogenesis Imperfecta = abnormal synthesis of Collagen I

Back 10

What is the cause of this?

Front 11

What are the clinical features of Osteogenesis Imperfecta?

Back 11

1. Generalized Osteopenia (brittle bones) = recurrent fractures & skeletal deformity
2. Blue Sclera
3. Early tooth loss
4. Joint Hypermobility
5. Deafness = due to involvement of teh bones of Inner & Middle ear

Front 12

Osteogenesis Imperfecta
-bones are calcified but hypodense b/c they are thin
-bent tibia shows fracture

Back 12

What is the cause of this?

Front 13

Osteogenesis Imperfecta
-Cortex is very thin
-Bone Trabeculae are thin, widely spaced, & fragile looking

Back 13

What is seen here?

Front 14

Osteogenesis Imperfecta
-Osteocytes are very close together = indicates insufficient Matrix synthesis
-Osteoblasts can't secrete enough Collagen I
-Blue staining shows that it is fully Calcified = not due to improper calcification

Back 14

What is seen here?

Front 15

Osteogenesis Imperfecta
-there is no impairment of Endochondral bone formation
-if you see a fracture site, you see excessive Cartilage formation since Collagen II is not impaired

Back 15

What is seen here?

Front 16

Osteogenesis Imperfecta post-fracture
-Cortex is thin
-can be mistaken for Osteosarcoma

Back 16

What is seen here?

Front 17

Hereditary disease with decreased Osteoclast function leading to decreased resorption & thick sclerotic bones

Back 17

Osteopetrosis

Front 18

What is the pathogenesis of Osteopetrosis?

Back 18

Impaired Osteoclastic resorption of bone leads to excessive bone formation

Front 19

Osteopetrosis
-Anemia, Thrombocytopenia = due to Trabeculae crowding out Bone Marrow

Back 19

Diagnosis?

Front 20

Osteopetrosis = dysfuction of Osteoclast activity
-"Erlenmyer Flask"-shaped deformity

Back 20

What is the cause of this?

Front 21

Osteopetrosis
-projections of dense bone down into the Metaphysis

Back 21

What is the cause of this pathology?

Front 22

Osteopetrosis
-persistence of lots of Cartilage in the matrix of Medullary Bone
-lack of Trabeculae or Hematopoietic marrow

Back 22

What is seen here?

Front 23

Osteopetrosis
-marked thickening of Trabeculae -> crowds out Bone Marrow
-Manifested by Anemia, Thrombocytopenia

Back 23

What is this?

Front 24

What is the Etiology of Fibrodysplasia Ossificans Progressiva (FOP)? Pathogenesis?

Back 24

Etiology: mutated genes for Bone Morphogenetic Proteins (BMP's)

Pathogenesis: in childhood, Osteoprogenitor cells of muscle begin progressive Endochondral Bone formation, in one muscle group after another

Front 25

Fibrodysplasia Ossificans Progressiva (FOP)

Overexpression of Bone Morphogenetic Proteins in muscle
-Osteoprogenitor cells of muscle, which normally wait for a fracture to occur so they can make a callus, go haywire & make bone in muscles

Back 25

This girl has a piece of bone in her Sternocleidomastoid muscle...what is the name of the disease? What is the cause?

Front 26

Fibrodysplasia Ossificans Progressiva

Back 26

What disease is this?

Front 27

Fibrodysplasia Ossificans Progressiva
-cannot surgically resect b/c it would cause more reactive bone formation

Back 27

This is seen in muscle. What disease?

Front 28

Fibrodysplasia Ossificans Progressiva

Back 28

What end-stage disease is this?

Front 29

What are the most common causes of Hypertrophic Osteoarthropathy?

Back 29

1. Bronchogenic Carcinoma = paraneoplastic syndrome
2. Chronic lung diseases
3. Cyanotic congenital heart disease
4. Inflammatory Bowel Disease

Front 30

Avascular Necrosis = ischemic necrosis of bone & bone marrow

Back 30

What pathology is seen here?

Front 31

What are the most common causes of Avascular Necrosis?

Back 31

1. Steroid use
2. Sickle Cell anemia
3. Caisson disease = decompression syndrome

Front 32

Advanced Avascular Necrosis
-pitted surface & cartilage disappears in places
-painful lesion

Back 32

What is seen here?

Front 33

Joint Mouse in Avascular Necrosis
-cartilage that was covering it regenerates & grows all around the outside -> causes difficulty in Articulation -> joints make a squeaky sound when bended

Back 33

What is seen here?

Front 34

Osteomyelitis
-Staphylococcus Aureus = MCC
-E. coli, Klebsiella, Salmonella

Back 34

What is seen here? What are the most common causes?

Front 35

Osteomyelitis
-Marrow space fills up with PMN's
-PMN's enzymatically destroy the bone

Back 35

What is seen here?

Front 36

Sequestrum in Osteomyelitis = necrotic bone due to compression of vasculature by Pyogenic Exudate

Back 36

What is seen here?

Front 37

Involucrum surrounding the Sequestrum
-Involucrum = Reactive Bone Formation in the periosteum = has Lamellar appearance

Back 37

What is seen here?

Front 38

Osteomyelitis
-Gelatinous inflammatory infiltrate in the medullary space = Sequestrum
-along the outside is new bone formation = Involucrum

Back 38

What is seen here?

Front 39

Osteomyelitis of the Phalanx
-infection has broken thru the bone, into the joint & has moved onto the next joint
-if infection hits the Growth Plate, it'll stop the growth of long bones = important in children

Back 39

What is happening here?

Front 40

Osteomyelitis that has drained to the outside
-predisposes to Squamous Cell CA of the skin

Back 40

What is this picture showing?

Front 41

Brodie's Abscess = surrounding wall of granulation tissue of inactive inflammation
-post-osteomyelitis

Back 41

What is seen here?