Week 1 - Bone, Cartilage and Arthritis

Arthritis almost universal in people > 75 yo

osteoarthritis

osteoarthritis age

men less than 50

women greater than 50

What type of arthritis involves soft tissue swelling, uniform loss of joint space, bony erosion

inflammatory

What type of arthritis involves juxta-articular osteopenia (bone mass loss)

inflammatory

What type of arthritis has non-uniform loss of joint space, osteophytes, and subchondral sclerosis (hardening of the bone just below the cartilage surface)

degenerative

What arthritis is caused by overuse of joints?

degenerative

What arthritis involves ST masses, early preservation of joint space, and well-marginated bone lesions

metabolic

most common arthritis

osteoarthritis

osteoarthritis is MC in which part of the spine

C5/6

what type of osteoarthritis has an unknown cause

primary

xray findings of osteoarthritis

joint space narrowing

osteophytes

subchondral sclerosis

which pain is distributed along dermatomes

radiculopathy

which pain is distributed along embryologic connections

sclerogenic

What artery supplies the primary growth center/diaphyseal region

nutrient a.

Which artery is subject to pooling/stasis at the growth plate

metaphyseal a.

Which artery is unable to cross cartilage growth plate prior to skeletal maturity

epiphyseal a.

Which artery is isolated before maturity

epiphyseal a.

T or F: cartilage contains VAN

false

chondro means

cartilage

What collagen makes up cartilage

type 2

What collagen makes up bone

type 1

What cartilage growth grows from within with new chondrocytes

interstitial

What cartilage growth increases length

interstitial

What cartilage growth grows on old chondrocytes

appositional

What cartilage growth increases width

appositional

Bone is radio______

dense

Air is radio_______

lucent

Solid periosteal reaction

- single layer, attached to cortex

- benign or slow growing lesion/ infection

Laminated periosteal reaction

- layers of growth not fully connected to cortex

- can be benign/aggressive

Spiculated periosteal reaction

- spicules of bone radiating away from cortex (hair-on-end)

- aggressive

Codman's triangle periosteal reaction

- pushes bone up creating a triangle

- aggressive condition like cancer

endosteal scalloping

thinning of cortex

the organic matrix is ____% of bone

35

the inorganic matrix is ____% of bone

65

What is the organic matrix made of

type 1 collagen

What is the inorganic matrix made mostly of

hydroxyapatite

Cortical bone aka

compact bone

What is the outer covering of a bone made of?

compact bone

What are the two layers of the periosteum

outer fibrous layer and inner cambium layer

Lamellar and woven bone

trabecular, cancellous, spongy bone

Where is the primary growth center located

diaphysis

What is the medullary cavity (yellow bone marrow) made up of

trabecular, cancellous, spongy bone

Where does osteoblastic/clastic activity occur?

inner cambium layer of periosteum

endosteum

what lines the margin of the cortex and all trabeculae

endosteum

End of the bone that supports articular cartilage

epiphysis

When the epiphysis matures, what is it made of

cancellous bone with a thin cortex

Where is the secondary growth center

epiphysis

Secondary ossification centers occur when

after birth

Physis aka

epiphyseal/growth plate

What is the epiphyseal plate made of before maturity?

cartilage

between physis and shaft

metaphysis

shaft of bone

diaphysis

What part of the bone contains bone marrow

diaphysis

most metabolically active part of the bone

metaphysis

stem cell of bone

osteoprogenitor cells

Where are osteoprogenitor cells found

periosteum and endosteum

What cells secrete and synthesize osteoids

osteoblasts

cytoplasm of osteoblasts contains what enzyme

alkaline phosphatase

What initiates bony mineralization

osteoblasts

What type of collagen do osteoblasts synthesize

1

what are the mediators of wolffs law

osteocytes

What are osteocytes?

mature osteoblasts in the lacunae of bone

what cells are responsible for bone resorption

osteoclasts

where are osteoclasts found

Howship's lacunae on bone surface

hyperemia is _______ blood flow

increased

During hyperemia osteolytic activity is _______

increased

What does hyperemia lead to

osteoporosis

What does ichemia lead to

bone sclerosis

Ischemia is ________ blood flow

reduced

Ischemia leads to _________ osteoblastic activity

increased

ossification occurs during weeks ________ during fetal development

6-8

Types of bone growth

endochondral and intramembranous

Bones form directly from osteoblasts

intramembranous ossification

Preexisting cartilage model calcifies and is replaced by bone

endochondral ossification