L17. Bone and Soft Tissue Pathology II

Paget's disease

Excessive bone resorption followed by abnormal bone formation

Paget's disease is also known as

osteitis deformans

True / False: Paget's disease has unknown etiology

true - genetics, virus, disease of osteoclasts

Paget's disease is --- or ---

mono or polyotic

majority are polystotic

What bone is commonly affected in Paget's disease?

Skull

Patient's with Paget's disease have a significantly higher risk of developing ----

osteosarcoma

In Paget's disease bone looks like af5 ---

jigsaw puzzle

Compound fracture

bone breaks through the skin

Comminuted bone fracture

bone fragments into many pieces

Greenstick fractures

usually seen in kids

bone breaks on one side and bends on the other

Displaced fracture

bone ends are out of normal alignment

Fracture Healing

Hematoma formation and inflammation = first week

Soft callus (2-3 weeks)

Hard callus (2-4 months)

Remodeling (several months to years)

Osteonecrosis presents as increased --- on radiographs

radio-opacity

What is the outcome of osteonecrosis?

removal of dead bone and formation of new bone

OR

bone collapse

What is present on an H and E in osteonecrosis?

No nuclei

No osteoblasts or osteoclasts

Why is cartilage difficult to heal?

It is avascular so difficult to regenerate

Osteomyelitis

infection of the bone and bone marrow

What is the most common cause of osteomyelitis?

staph aureus

Children can be diagnosed with osteomyelitis secondary to ---

hematogenous spread (spread though blood)

Adults can be diagnosed with osteomyelitis secondary to ---

open bone fracture

What is the most common cause of osteomyelitis in patients with sickle cell anemia?

salmonella

What is needed for diagnosis of osteomyelitis?

bone biopsy / culture and blood culture

True / False: patients with osteomyelitis are typically extremely sick (fever, malaise, elevated ESR)

true

True / False: in reference to osteomyelitis, radiographic changes can be minimal or radiolucency with rim of sceloris

true

Chronic osteomyelitis symptoms include low grade fevers, inflammation persists for months to years with presence of --- and ---

necrotic bone and fistulous tract

What are the most common causes of chronic osteomyelitis?

Diabetes

Peripheral vascular disease

Types of joints

synovial

non-synovial

Non-synovial joints

Fibrous

- tooth socket = gomphosis

Cartilaginous

- intervertebral discs and pubic symphysis

What is the function of synovial fluid?

allows articulating surfaces of bones to glide upon each other

Articular cartilage is a specific type of --- that covers the ends of bones in joints and provides a smooth surface for movement

hyaline cartilage

Synovial lining is filled with --- (phagocytes) and --- (fibroblasts)

synoviocytes A = phagocytes

synoviocytes B = fibroblasts

Synoviocytes secrete ---

hyaluronic acid

Synovial membrane is surrounded by a ---

fibrous capsule

True / False: hyaline cartilage is vascularized

false = avascular

True / False: hyaline cartilage lacks blood vessels, lymphatics, and nerves. It is made of water, hyaluronic acid, proteoglycans, and collagen type II

true

Degenerative joint disease is also referred to as ---

osteoarthritis

Osteoarthritis

inflammation and and degeneration of joints

results in overuse and wear of the bones

Osteoarthritis is an --- disease

over-use

inflation and degeneration of joints resulting in the interaction of articulating surfaces with one another

Rheumatoid arthritis

systemic auto-immune disorder

inflammation of synovial joints

Who is more prone to rheumatoid arthritis?

Females > males

30 - 50 years old

Rheumatoid arthritis has ---- meaning it effects blood vessels, lungs, heart, and skin

extra-articular effects

What is the genetic factor increase for rheumatoid arthritis?

HLA II + environment

Inflammatory cytokines

IL-1, IL-6, TNF-alpha

What is the term for inflammatory cells in rheumatoid arthritis?

pannus

What is the difference in systems affected in osteoarthritis versus rheumatoid arthritis?

OA: affects weight bearing joints

RA: affects small joints

Rheumatoid arthritis is a --- arthritis affecting small joints of the hands and feet = metacarpal phalanges (MCP) and proximal inter carpal phalanges (PIP)

symmetric

What is the key feature of rheumatoid arthritis progression?

Pannus = thickened abnormal soft tissue mass in joint space

- inflammatory cells, lymphocytes, plasma cells, macrophages, dendritic cells

True / False: angiogenesis contributes to all bone diseases

true

What is the end result of rheumatoid arthritis?

fibrous and bony ankylosis

What is the clinical course of rheumatoid arthritis?

chronic with acute exacerbations

Treatment for rheumatoid arthritis?

NSAIDS

COX-2 inhibitors

TNF antagonists

methotrexate

Lesion created by rheumatoid arthritis

rheumatic nodulus

Septic arthritis

hematogenous spread of infection to synovial joints

Gout

uric acid crystal deposition in joints and soft tissues

type of arthritis

Pseudogout

calcium pyrophosphate crystal deposition in joints and soft tissues

Main lesions created by gout

tophus at tendons and ligaments

Gout have --- shaped crystals that are --- for birefringence

needle shaped crystals

negative for birefringence

Pseudogout have --- shaped crystals that are --- for birefringence

rhomboid shaped crystals

postive for birefrigence

Which has chalky deposits: gout or pseudo gout

pseudogout

TRue / False: pseudo gout may be confused with differential diagnoses of osteoarthritis, gout, and mycobacterial infections due to granulomatous histological presentation

true