Bones, Joints, and Soft Tissue Part 1 (Dr. Martin) Flashcards
What is the most common skeletal dysplasia and is a major cause of dwarfism?
Achondroplasia
What gene is mutated with achondroplasia?
What is the inheritance pattern?
1) FGFR3
2) AD
What is the most common lethal form of dwarfism?
Thanatophoric Dysplasia
What physical feature is noteworthy with achondroplasia?
With thanatophoric Dysplasia?
1) Normal trunk length
2) Small chest cavity
Osteoporosis or osteopetrosis involves what receptor?
LPR5 receptor
Decreases or absent osteoclasts is due to mutations in?
RANKL
What is the most common inherited disorder of connective tissue?
Type 1 Collagen Disease Osteogenesis Imperfecta
What are mutated with Type 1 Collagen Disease Osteogenesis Imperfecta?
What is the inheritance pattern?
1) α1 and α2 chains of type I collagen
2) AD
Which type of Osteogenesis Imperfecta has the worst prognosis in that it is uniformly fatal in utero?
Which has the best prognosis in which they live a normal life span?
1) Type II
2) Type I
What is the clinical presentation of Type I collagen disease?
1) Fractures during childhood that decrease at puberty
2) Blue sclera
3) Hearing loss
4) Brittle teeth
Type II collagen disease is frequently lethal at or shorty after birth often due to?
Respiratory problems
Osteopetrosis aka Marble Bone Disease is due to mutation in what gene that encodes proton pumps on surface of osteoclasts?
This causes what deficiency?
1) CLCN7
2) CA2 (carbonic anhydrase
Due to deficient osteoclast activity with osteopetrosis, what do bones lack?
The ends of long bones are bulbous which is known as?
1) Medullary canal
2) Erlenmeyer flask deformity
The severe infantile type of osteopetrosis has what inheritance pattern?
What cranial nerve deficits are noted?
1) AR
2) Optic atrophy, deafness, facial paralysis
Mucopolysaccharidoses are a group of lysosomal storage diseases which result in mucopolysaccharides from the extracellular matrix accumulating inside?
Chondrocytes
What differentiates osteopenia and osteoporosis?
1) Osteopenia is characterized by bone mass 1-2.5 SD below the mean
2) Osteoporosis is bone mass at least 2.5 SD below mean
Atraumatic or vertebral compression fractures signifies?
Osteoporosis
What are the most common forms of osteoporosis?
1) Senile
2) Postmenopausal
Osteoporosis in adolescents girls can occur due to insufficient intake of what?
Calcium
Postmenopausal osteoporosis is mostly due to what deficiency?
Estrogen deficiency
What is morphologically seen with osteoporosis?
Decreased quantity of trabecular bone
Postmenopausal osteoporosis affects bones with increased surface area such as?
Cancellous bones of vertebral bodies
What race has an increased risk for osteoporosis?
Eating too much of what can increase the risk?
What environmental factor is common in increasing risk?
1) Caucasian
2) Phosphorus (in soda)
3) Smoking
What test is used for diagnosis of osteoporosis?
DEXA-scan
What is clinically common to see with osteoporois?
Thoracic and lumbar fractures
What causes loss of height in osteoprosis?
Lumbar lordosis and kyphoscoliosis
What is characterized by increased but disordered and structurally unsound bone mass?
Paget Disease (osteitis deformans)
What bones are most commonly affected with Paget disease?
1) Axial skeleton
2) Femur
What distinct appearance of the skull does Paget disease have on XR?
Cotton Wool
What is the hallmark of Paget disease?
What appearance does this cause?
1) Mosaic pattern of woven and lamellar bone, seen in the sclerotic phase
2) Jigsaw-puzzlelike with prominent cement lines
What complication may occur in long bones in Paget patients?
What tumor like condition may develop with Paget disease?
1) Chalk stick type fracture
2) Sarcoma
What levels of serum ALK phosphatase, calcium, and phosphorus with Paget disease?
1) Increased serum ALK phosphatase
2) Normal calcium and phosphorus
Rickets and osteomalacia are due to?
Rickets is the disease of what population?
Osteomalacia?
1) Vitamin D deficiency
2) Children
3) Adults
What hormone plays a central role in calcium homeostasis?
PTH
Hyperparathyroidism leads to significant skeletal changes related to unabated activation of?
Osteoclasts
What disease is characterized by increased bone cell activity, peri-trabecular fibrosis, and cystic brown tumors?
It is a hallmark of?
1) Osteitis fibrosa cystica (von Recklinghausen disease of bone)
2) Severe hyperparathyroidism
The decreased production of what secreted factors can lead to renal osteodystrophy?
1) BMP7
2) FGF-23
3) Klotho
What type of fracture is characterized by extending only partially through the bone and is common in infants when bones are soft?
Greenstick fracture
What type of fracture is characterized by bone breaking skin surface?
Which is when bone is fragmented?
1) Compound
2) Comminuted
In the healing of fractures, degranulated platelets and migrating inflammatory cells release what factors to trigger osteoprogenitor cells and stimulate osteoclast and osteoblast activity?
1) PDGF
2) TGF-beta
3) FGF
In the healing of fractures, after how long does the soft tissue callus transform into bony callus?
After 2 weeks
In the healing of fractures, when the callus is reduced in size, the outline of fractured bone are reestablished as?
The healing process is complete with restoration of?
1) Lamellar bone
2) Medullary cavity
What is characterized by infarction of the bone and the marrow?
Osteonecrosis (avascular necrosis)
Most cases of osteonecrosis are due to what causes?
1) Fractures
2) Corticosteroid tx
In regards to osteonecrosis what type of infarct causes pain and may lead to secondary osteoarthritis?
Which are clinically silent and involve trabecular bone and marrow?
1) Subchondral infarcts
2) Medullary infarcts
What can lead to osteonecrosis of the jawbone?
Bisphosphonate therapy
What is characterized as inflammation of bone and marrow secondary to infection?
What are the most common causes?
1) Osteomyelitis
2) Pyogenic bacteria and mycobacteria
What is the most common cause of pyogenic osteomyelitis in children?
Bacterial infection reaching the bone via hematogenous spread
What bacteria is the most common cause of pyogenic osteomyelitis?
Staph aureus
What bacteria is the most common cause of pyogenic osteomyelitis in sickle cell patients?
Salmonella typhi
In acute osteomyelitis in kids, what may form and dissect for long distance along the bones surface?
What follows this?
1) Subperiosteal abscesses
2) Sequestrum (dead bone)
In infants what can acute osteomyelitis lead to?
Septic or suppurative arthritis
With chronic osteomyelitis, what is characterized by newly deposited bone forming a shell of living tissue around the segment of devitalized bone?
Involucrum
What histologic findings are associated with mycobacterial osteomyelitis?
1) Caseous necrosis
2) Granulomas
What complication involving the spine occurs in 40% of mycobacterial osteomyelitis cases?
Tuberculosis Spondylitis (Pott Disease)
Tuberculosis Spondylitis (Pott Disease) leads to?
Permanent compression spine fractures
How can congenital syphilis affect bone?
How does acquired syphilis?
1) Saber shin
2) Saddle nose
