Musculoskeletal - Pathoma Flashcards
The driving etiology for achondroplasia is an ________expression of ________.
The driving etiology for achondroplasia is an overexpression of FGFR3.
True/False.
Most cases of achrondoplasia are sporadic and related to advanced paternal age.
True.
Identify which (if any) of the following are affected by achrondroplasia:
Mental function
Lifespan
Fertility
No effects on mental function, lifespan, or fertility
What are the three common features of osteogenesis imperfecta?
Multiple fractures (absent bruising can distinguish from child abuse)
Blue sclera (increased exposure of choroidal veins)
Hearing loss (easy fracture of middle ear bones)
Osteo_________ is a disorder of bone mineralization.
Osteo_________ is a disorder of bone mass.
Osteo_________ is a disorder of bone resorption.
Osteomalacia is a disorder of bone mineralization.
Osteoporosis is a disorder of bone mass.
Osteopetrosis is a disorder of bone resorption.
Osteopetrosis is a(n) _____________ (sporadic/inherited) defect of bone _____________ (formation/mineralization/resorption).
Osteopetrosis is an inherited defect of bone resorption.
What is the main result of the lack of bone resorption seen in osteopetrosis?
Abnormally thick, heavy bone which fractures easily
Osteopetrosis occurs due to poor ____________ function.
Osteopetrosis occurs due to poor osteoclast function.
Osteopetrosis often occurs due to a mutation in ________________, leading to a loss of the ________ microenvironment needed for bone resorption.
Osteopetrosis often occurs due to a mutation in carbonic anhydrase II, leading to a loss of the acidic microenvironment needed for bone resorption.
Name some of the major presenting S/Sy of osteopetrosis:
F______________
A______________, T______________, L______________
V______________ and H______________ impairment
H______________
R________________________
Name some of the major presenting S/Sy of osteopetrosis:
Fractures**
Anemia, **Thrombocytopenia, Leukocytopenia**
Visual** and Hearing** impairment
Hydrocephalus
Renal tubular acidosis(type 2)
Why is osteopetrosis associated with hydrocephalus?
Narrowing of the foramen magnum
Why is osteopetrosis associated with type 2 RTA?
Lack of carbonic anhydrase
(leading to decreased tubular HCO3- reabsorption)
What is the treatment for osteopetrosis?
Bone marrow transplant
(osteoclasts derive from monocytes)
A defect in mineralization of osteoid in children is called ___________.
A defect in mineralization of osteoid in adults is called ___________.
A defect in mineralization of osteoid in children is called Rickets.
A defect in mineralization of osteoid in adults is called osteomalacia.
Osteoblasts normally produce ________, which is then mineralized with calcium and phosphate to form bone.
Osteoblasts normally produce osteoid, which is then mineralized with calcium and phosphate to form bone.
Osteomalacia/Rickets results due to a lack of ________.
Osteomalacia/Rickets results due to a lack of vitamin D.
Vitamin D deficiency can lead to osteo_________.
Vitamin D deficiency can lead to osteomalacia.
Rickets most commonly arises in children of what age?
< 1 year
What are some of the S/Sy of Rickets?
Pigeon-breast deformity (inward bend of the ribs + sternal protrusion)
Frontal bossing (osteoid deposition in skull)
Rachitic rosary (osteoid deposition at costochondral junction)
Genu varum (in ambulating children)
What are some of the clinical S/Sy of osteomalacia in relation to the bones?
Weak bones;
pathologic fractures
What are some of the laboratory S/Sy of osteomalacia?
Decreased: calcium, phosphate
increased PTH, alkaline phosphate
Peak bone mass is achieved at ____ years of age and is based on genetics (___________ receptor variants), diet, and exercise.
Peak bone mass is achieved at 30 years of age and is based on genetics (vitamin D receptor variants), diet, and exercise.
After peaking at 30 years of age, ____% is typically lost each year.
After peaking at 30 years of age, 1 % is typically lost each year.
How can bone density be measured?
DEXA scanning
What are some of the laboratory S/Sy of osteoporosis?
Normal: Ca2+, PO43-, PTH, ALP
How can osteoporosis and osteomalacia be easily distinguished, despite similar presentation of weak bones and pathologic fractures?
Lab values
(normal in osteoporosis; elevated PTH and ALP + decreased Ca2+ and PO43- in osteomalacia)
True/False.
Osteoporosis treatment includes exercise, vitamin D, calcium, bisphosphonates, estrogen replacement, and glucocorticoids.
False.
Osteoporosis treatment includes exercise, vitamin D, calcium, and bisphosphonates.
Estrogen replacement is not currently recommend** and glucocorticoids **are contraindicated (as they worsen osteoporosis).
How do bisphosphonates treat osteoporosis?
By inducing osteoclast apoptosis
(by binding hydroxyapatite at the pyrophosphate-binding site)
Among the following, identify which produce an elevation in ALP:
Achondroplasia
Osteoporosis
Osteomalacia
Osteopetrosis
Osteomyelitis
Paget disease of the bone
Osteogenesis imperfecta
Osteomalacia (+ elevated PTH)
Paget disease of the bone
What is the underlying cause of Paget disease of the bone?
Imbalance between osteoblast and osteoclast function
(though we don’t know why - may be a viral cause)
What is the most common cause of an isolated elevation of ALP in patients over 40?
Paget disease of the bone
True/False.
Paget disease of the bone is a systemic process involving multiple bones (sometimes widespread skeletal involvement).
False.
Paget disease of the bone is a localized process involving one or more bones.
How is Paget disease of the bone treated?
Calcitonin
+
Bisphosphonates
What are the three distinct phases of Paget disease of the bone?
(1) O____________
(2) M________________________
(3) O____________
What are the three distinct phases of Paget disease of the bone?
(1) Osteoclastic**
(2) M_ixed osteoclastic-osteoblastic_
(3) Osteoblastic**
The end result of Paget disease of the bone is _______, _______ bone that ________ easily.
The end result of Paget disease of the bone is thick, sclerotic bone that fractures easily.
Name some of the clinical features of Paget disease of the bone:
Bone ____________
Increasing H____________
H____________ loss
L____________
Name some of the clinical features of Paget disease of the bone:
Bone pain
Increasing Hat size
Hearing loss
L_ion-like facies_
What is the lab finding of Paget disease of the bone?
Isolated ALP elevation
What does bone biopsy reveal in Paget disease of bone?
Mosaic pattern of lamellar bone
Name two major complications of Paget disease of the bone.
High-output cardiac failure (due to formation of AV shunts in bone)
Osteosarcoma
Osteomyelitis most commonly occurs in _________ (age group), is _________ (general etiology), and results due to _________ spread.
Osteomyelitis most commonly occurs in children, is bacterial, and results due to hematogenous spread.
Transient bacteremia (often in _________) often seeds the ______physis.
Open-wound bacteremia (often in _________) often seeds the ______physis.
Transient bacteremia (often in children) often seeds the metaphysis.
Open-wound bacteremia (often in adults) often seeds the epiphysis.
Name the etiology associated with osteomyelitis in each of the following scenarios:
Most common cause (90% of cases)
Sexually active young adults
Sickle cell disease
Diabetes
IVDUs
Cat or dog bites
Involving the vertebral column
- E. coli*
- N. gonorrhoeae*
- Salmonella spp.*
- Pseudomonas spp.*
- Pseudomonas spp.*
- Pasturella multocida*
- Mycobacterium tuberculosis*
How is the diagnosis of osteomyelitis made?
Blood culture
What are the clinical features of osteomyelitis?
Bone pain + systemic signs of infection (fever/leukocytosis)
lytic focus surrounded by sclerotic bone (abcess/sequestrum surrounded by involucrum)
Avascular bone necrosis is typically ischemic necrosis of what?
Bone and bone marrow
What are the most common causes of avascular necrosis of bone?
Trauma and/or fracture
Besides trauma/fracture, name two other causes of avascular necrosis.
Sickle cell disease
Caisson disease
Where do osteomas most commonly arise?
The facial bones
(most commonly associated with Gardner syndrome)
What are osteoid osteomas?
Benign osteoblast tumors surrounded by a rim of reactive bone
What demographic is more commonly affected by osteoid osteomas?
Males < 25 years of age
Where do osteoid osteomas typically arise?
Cortex of long bones
Osteoid osteomas present as bone _______ that resolves with _______.
Osteoid osteomas present as bone pain that resolves with aspirin.
How do osteoid osteomas present on imaging?
Bony mass (< 2 cm) with a lucent core (osteoid)
What tumor is similar to an osteoid osteoma but is larger (>2 cm), arises in the vertebrae (as opposed to the long bones), and does not respond to aspirin?
Osteoblastomas
What is the most common benign tumor of bone?
Osteochondroma