MSKS Pathology Lecture 1_Bone Pathology Flashcards
Osteopenia vs Osteoporosis
Osteopenia is bone loss up to 2.5 SD from the mean. osteoporosis is bone loss greater than 2.5 SD. Pathology like increased bone fractures generally do not occure until the condition has progressed to osteoporosis. These lead to reduced bone mass but the remaining bone is structurally normal.
What are the 7 types of bone fracture?
see attached
What disorder does reduced HOXD13 cause?
brachydactyly, which is charicterized by shortened digits, particularly the thumb
What causes osteopetrosis? what are two clinical manifestations?
It is caused by Reduced bone resorption because of impaired formation or function of osteclasts, often resulting from problems with the enzymes. It can cause bones to be mishapen at the distal ends and for them to have no medulary canal
What can help prevent Osteoporosis?
Exercise, Ca++ and Vit D, bisphophonates (reduce osteoclast activity)
What does reduced/ nonfunctional RUNX2 cause?
cleidocranial dysplasia. This is because RUNX2 is essential for the differantiation of osteoprogenitor cells into osteoblasts in Intramembranous ossification
Discuess Renal Osteodystrophy. What does it cause, what is its pathogenesis?
See attached
What is Osteonecrosis
It is an infarction of bone and bone marrow which creates an Empty lacunae
What two factors increase risk of osteoporosis? Why?
being Postmenopausal because this increases osteoclast activity. Also aging can decrease osteoblast activity.
What causes Mucopolysaccharidoses?
It is caused by some types of lysosomal defects. These defects cause Mucopolysaccharids to accumulate in chondrocytes leading to apoptosis which prevents normal cartilage formation.
What condition is caused by reduced FGFR3 activity?
achondroplasia and thanatophoric dysplasia (both are forms of dwarphisim)
What causes osteogenesis imperfecta?
osteogenesis imperfecta is caused by problems with too little or nonfunctional collegen in the bones
What does Hyperparathyroidism cause
See attached
Osteoporosis, brown tumors, osteitis
fibrous cystic
What is Osteomyelitis? What causes it?
Inflammation of the bone and marrow. It is nearly always secondary to infection. The most common causes of infection are mycobacteria and pyogenic bacteria
Who is most at risk for osteomyelitis?
In the US, found especially in immunosuppressed individuals and
immigrants from developing countries. Also common in people with open fractures, surgical procedures and diabetic infections of the feet
