Musculoskeletal Disorders Part 1 Flashcards
What is mutated in osteogenesis imperfecta?
Type 1 collagen (alpha 1 or alpha 2 chains)
What is another name for osteogenesis imperfecta?
Brittle bone disease
What is the frequency of osteogenesis imperfecta?
1:20,000 live births
How is type I collagen affected by osteogenesis imperfecta?
Premature breakdown of collagen
Osteogenesis imperfecta follows what type of genetic pattern?
Autosomal dominant
What is the main location affected by osteogenesis imperfecta?
Extracellular matrix (ECM)
What are the specific areas affected by osteogenesis imperfecta?
Eyes, inner ear bones, skin, joints, teeth
Osteogenesis imperfecta affecting the inner ear bones can lead to what issue?
Deafness
What type of osteogenesis imperfecta results in a normal lifespan nonetheless?
Type I
Which type of osteogenesis imperfecta is lethal in utero?
Type II
What are the two extreme issues with type II osteogenesis imperfecta?
Cerebral hemorrhage and respiratory failure
Why is cerebral hemorrhage common with type II osteogenesis imperfecta?
Weak skull
What is the unique effect of osteogenesis imperfecta on the eye?
Abnormal collagen of the sclera (choroid) giving a bluish appearance instead of white
With what type of osteogenesis imperfecta does abnormal collagen of the sclera occur?
Type I
Multiple fractures, extremity bowing, scoliosis, ligamentous laxity (dislocations), and hearing loss are associated with what musculoskeletal congenital disorder?
Osteogenesis imperfecta
What is an important chiropractic note to remember with those with osteogenesis imperfecta?
Their bones are extremely fragile (low force adjustments)
The fragility of the bones of patients with osteogenesis imperfecta is a contraindication to what type of adjustments?
Extremity adjustments
The zebra stripe sign is associated with what musculoskeletal congenital disorder?
Osteogenesis imperfecta
What is the treatment used for children with osteogenesis imperfecta?
Bisphosphonates
What is the most common form of dwarfism?
Achondroplasia
What are the results of achondroplasia?
Decreased cartilage synthesis and decreased growth plate expansion
What location is specifically affected by the decreased cartilage synthesis with achondroplasia?
Growth plate
What is the genetic mutation with achondroplasia?
Fibroblast growth factor receptor (FGFR3) mutation
What is the result of a FGFR3 mutation in achondroplasia?
Inhibition of epiphyseal (growth plate) chondrocytes
Is achondroplasia usually sporadic or inherited?
Sporadic (75%)
What is the genetic pattern of achondroplasia?
Autosomal dominant
What musculoskeletal congenital condition is accompanied by short proximal extremities, lower extremity bowing, frontal bossing, and mid face hypoplasia (low nasal bridge)?
Achondroplasia
What percentage of achondroplasia diagnoses are inherited?
25%
What is frontal bossing (as seen in achondroplasia)?
Rounding of the frontal bone
What type of dwarfism is primarily endocrine oriented and is more rare than achondroplasia?
Hypopituitary dwarfism
What is the frequency of achondroplasia?
1:10,000
Spinal issues including hyperlordosis and hyperkyphosis at birth, bullet vertebrae, scoliosis, and spinal stenosis are common among which musculoskeletal genetic disorder?
Achondroplasia
What two specific types of spinal stenosis are common among achondroplasia patients?
Foramen magnum stenosis and spinal canal stenosis
What is usually the death of those with achondroplasia?
Brain stem compression
What is the result with brain stem compression with achondroplasia?
Cardiovascular abnormalities (may be lethal)
What type of dwarfism is completely fatal?
Thanatophoric dwarfism
What is the frequency of thanatophoric dwarfism?
1:20,000 births
Extremely small thorax with shortened long bones leading to perinatal respiratory failure occurs with which musculoskeletal congenital disorder?
Thanatophoric dwarfism
What is the unique appearance of the vertebrae in patients who have achondroplasia?
Bullet-shaped
What is trident hand that is associated with achondroplasia?
Underdevelopment of the bones in the hands
What rare genetic disorder is a result of decreased osteoclast-mediated bone resorption?
Osteopetrosis
What type of bone cell is inhibited in osteopetrosis & what is the result of that?
Osteoclasts; osteoblasts therefore overwork and build up extreme bone density leading to increased fractures
Why are cranial nerve palsies associated with osteopetrosis?
Foraminal stenosis occurs narrowing the bony canals for the nerves
Why is deranged hematopoiesis common with osteopetrosis?
The medullary cavity fills with extra bone due to the decreased osteoclast activity
What are some issues that occur when the medullary cavity fills with excess bone in osteopetrosis?
Hepatosplenomegaly, recurrent infections, anemia
Why does hepatosplenomegaly occur with osteopetrosis?
The liver and spleen attempt to take over the function of the bone marrow that has been compressed and therefore hypertrophy
What is the treatment for osteopetrosis?
Stem cell replacement
Erlenmeyer flask deformity is present among which musculoskeletal disorder?
Osteopetrosis
What is the most important form of osteopenia?
Osteoporosis
What is the general definition of osteoporosis?
Loss of bone mass and increased porosity
What is osteopenia?
Reduced bone mineralization
At what point does osteopenia become the severe form of osteoporosis?
T score of 2.5 standard deviation (threshold from the norm)
What is usually the cause of localized osteoporosis?
Disuse/isolation (example = arm in a cast)
What is the most common type of osteoporosis?
Primary
When does primary osteoporosis occur?
Postmenopausal, senile (age-related)
Neoplasia, hyperparathyroidism, nutrient deficiency, and drug exposure are causes of what which type of osteoporosis?
Secondary
Enlargement of what organ is a cause of secondary osteoporosis?
Parathyroid
What types of drugs can be a cause of secondary osteoporosis?
Alcohol, smoking, long term corticosteroids
Osteoporosis is more likely to affect what kind of bone?
Trabecular (cancellous/spongy) bone
How is the cortex of the bone affected by osteoporosis?
Thinned (not completely destroyed)
What are specific common locations of fractures as a result of osteoporosis due to these areas possessing increased amounts of trabecular bone?
Vertebral bodies, femoral neck, calcaneus
What type of bone cell is less impacted by aging and therefore retains normal activity?
Osteoclasts
Beginning in mid-20s, bone loss occurs at what rate?
.5% per year
What percentage of postmenopausal women experience an osteoporosis related fracture?
50%
What percentage of males (of the same age as postmenopausal women) experience an osteoporosis related fracture?
3%
Reduction in what hormone accelerates bone loss as seen in postmenopausal women with osteoporosis?
Estrogens
Activity of what substances are decreased in senile osteoporosis?
Growth factors and osteoblasts
What is the age of maximum bone density?
Mid adulthood (25 years of age)
How can osteoporosis be prevented?
Diet and exercise
What types of exercise can help prevent osteoporosis?
Resistance training, athletics, increasing weight load more than overall cycles
What supplements may benefit those with or prevent osteoporosis?
Calcium and vitamin D
Calcium and vitamin D deficiency are most common among what gender?
Females
Who are at risk for osteoporosis?
Older people of both ages, postmenopausal women
Osteoporosis is usually asymptomatic, true or false?
True
When does osteoporosis become symptomatic?
With skeletal fragility
What is the exaggerated forward hunching of those with osteoporosis called that is due to multiple compression fractures?
Dowager’s hump
What are some concerns following surgery for a femoral neck (hip) fracture?
Pneumonia, deep vein thrombosis, pulmonary embolism (result of disablement)
What type of bone cells is affected by the menopausal cause of osteoporosis?
Osteoclasts (increased)
What type of bone cells is affected by the aging cause of osteoporosis?
Osteoblasts (decreased synthesis)
What hormone is decreased with the menopausal cause of osteoporosis?
Estrogen
What is another feature important to consider with the aging cause of osteoporosis besides the reduction in osteoblast synthesis?
General sedentary lifestyle
What is the treatment for osteoporosis in females?
Estrogen therapy
What are some risk factors with estrogen treatment for osteoporosis?
Deep vein thrombosis (increased blood clots), endometrial cancer, and breast cancer
What is the appropriate way of determining osteoporosis?
DEXA scan
What are preventative mechanisms for osteoporosis?
Activity, supplements, bisphosphonates
