Lec. 1: Diseases and disorders of bone Flashcards
Diseases and Disorders of bone can be divided into 4 different areas
- Responses to stress
- Congenital
- Disorders of epiphyses & epiphyseal growth
- Metabolic
(3) Bone disorders with the responses to Stress/Injuries
Altered deposition of bone
Altered resorption of bone
Mechanical failure (fracture)
Altered deposition of bone, can be and give an example
- Localized or generalized, increased or decreased
- Osteoporosis: decreased bone deposition
Altered resorption of bone can be and give and example
- Localized or generalized, increased or decreased
- Osteopetrosis: decreased bone resorption
Some examples of localized congenital abnormalities
- Clubfoot
- Coxa Vara
- Congenital dislocation of hip
- Congenital amputations
- Nursemaid’s elbow
- Spina Bifida
- Hypoplasia of tibia, fibula, femur, radius, clavicle
- Torticollis
- Scoliosis
- Sprengle deformity (micro scapula)
Some examples of Generalized congenital abnormalities
- Osteogenesis Imperfecta
- Achondroplasia
- Marfan Syndrome (Hyperchondroplasia)
- Osteopetrosis
Osteogenesis Imperfecta
Congenital osteoporosis → with resultant pathological fractures
Mutations of Type I collagen genes cortical thinning (Main type in bone and ligaments)
Four types classified
Osteogenesis Imperfecta type 1
- most mild
- most common
- fractures appear after child starts walking
- blue sclerae
- head appears large compared to body
- limbs deformed
- deafness my occur
- teeth may be affected
- bones seem to strengthen after puberty
Osteogenesis Imperfecta type 2
- most severe
- typically fatal in pre-natal period
Osteogenesis Imperfecta type 3
- Severe
- multiple fractures at birth
- premature closing of epiphyseal plates –> skeletal deformity
- -Kyphosis
- -Scoliosis
- -Dwarfism
- Typically non-ambulatory
- Sclerae blue at first and then turn white
Osteogenesis Imperfecta type 4
- Similar to type 1
- but, normal sclera
- dentinogenesis imperfecta present
Which Osteogenesis Imperfecta is the most severe
Type 2
Which Osteogenesis Imperfecta has blue eyes
Type 1 and type 3. But type 3 later turns white
Which Osteogenesis Imperfecta has premature closing of epiphyseal plates
Type 3
What is the treatment for Osteogenesis Imperfecta
- Prevent fractures: splinting and bracing
- Treat fractures/surgical rods
- Gene therapy
What is achondroplasia
- Dwarfism
- Autosomal dominant abnormality/spontaneous chromosomal defect
- Limbs are shorter disappropriate to trunk (1/2 of normal length)
- Failure of longitudinal growth in cartilage of epiphyseal plate
- Normal cognition and normal life expectancy
- Total height typically under 4 feet
- may lead to spinal stenosis
Marfan syndrome is also known as
Hyperchondroplasia
Marfan’s Syndrome is
- Autosomal dominant abnormality / spontaneous chromosomal defect
- Excessive length of limbs due to excessive longitudinal growth in cartilage of epiphyseal plate - arm span greater than height
- Systemic –affects vision and CV system
Musculoskeletal findings for someone with Marfan’s Syndrome
Muscular weakness Joint laxity Flat feet Scoliosis Depressed sternum
Treatment –sx for deformities if it affects function
What is osteopetrosis
Failure of osteoclasts to remove mineralized bone
Bone “piles up” Bone appear dense on X ray
Mechanically weak → fracture easily
Bone marrow displaced → anemia
Why is someone with osteopetrosis mechanically weak
bone is disorganised
What are the 2 forms of osteopetrosis
malignant infantile form
benign form
Explain the malignant infantile form of osteopetrosis
- Recessive gene
- Typically fatal by 10-years-old
- Can be treated with bone marrow transplant
Explain the benign form of osteopetrosis
- Autosomal dominant
* Symptoms can include fractures, frequent infections, blindness, deafness, and strokes
Generalized disorders of epiphyses & epiphyseal growth
- marfan syndrome
- achondroplasia
Localized disorders of epiphyses & epiphyseal growth
- Osteochondroses
- Partial avulsions
- Disorders of growth plate (SCFE most common)
Osteochondroses is and general features
- Idiopathic disorders of the epiphyses with common denominator of avascular necrosis
- Affects Boys > girls
- Ages 3 - 10years
- self limiting
- has Four phases
Phase 1 of Osteochondrosis
- Quiet Phase
- Obliteration of blood vessels to epiphysis –> decreased blood flow
- No real symptoms, no real deformity
Phase 2 of Osteochondrosis
- Revascularization with deposition / resorption
- Pathologic fracture of subchondral bone
- Epiphysis may become deformed with abnormal forces
Phase 3 of Osteochondrosis
- Bone healing
* Bone deposition continues
Phase 4 of Osteochondrosis
Residual deformity persists
Name 3 Specific Conditions of Osteochondroses and which bones they affect
-Legg Perthes disease
(femoral head, 12% of cases bilateral)
-Panner disease
(Capitulum)
-Kienbock disease
(Lunate)
*Legg Calve Perthes disease
- Pain can be at the hip and can refer to the knee
- flattened femoral head
- femur is not in the correct position
- loss of abduction noted
What is a possible reason that a partial avulsion might happen and why?
-rapid growth spurt because wolff’s law hasn’t had time to make the bone strong
Name two types of partial avulsions
- osgood schlatter disease
- sever disease
Osgood schlatter disease, where does it happen and who is at risk
Tibial tubercle
Boys typically 10-15 years old
Sever disease, where does it happen and who is at risk
Calcaneal tubercle
Boys typically 8-15 yrs old
What is the most common disorder of the growth plate
SCFE
What does SCFE stand for
Slipped capital femoral epiphysis
What are the general characteristics of SCFE
- Boys > girls
- ≥ 9 years old
- 30% chance of subsequent involvement of second hip –Higher risk if endocrine imbalance
- –> Adolescent male with underdeveloped genitalia and female fat distribution most at risk
Does SCFE have a systemic component
*yes, someone is at a higher risk if they have an endocrine imbalance
*Which condition affects abduction
Legg Calve Perthes disease
*Which condition affects internal rotaton
SCFE
How would someone present with slipped capital femoral epiphysis
- Loss of IR
- involved leg appears shorter
- Requires surgery
Name metabolic bone conditions (5)
- Rickets/Osteomalacia
- Osteoporosis
- Hypopituitarism
- Hyperpituitarism
- Paget Disease
what is rickets/osteomalacia
- Rickets is a disease of children (growing bone), where as osteomalacia is an adult disease (after physis closed)
- Both result in “soft bones”
- Failure of calcium salts to deposit normally
- Main causes include vitamin D deficiency, chronic renal insufficiency, and renal tubular insufficiency
*What can a deficiency in vitamin D cause
rickets / osteomalacia
What is the female-athlete triad and what is the other name for this
eating disorder, amenorrhea, and osteoporosis now called REDS
REDS
What are common fracture sites for osteoporosis
vertebra
hip
wrist
What is the most common metabolic bone disease
osteoporosis
Someone with hyperpituitarism may develop
May develop arthritis, osteophytes, spine pain, etc.
Acromegaly affects and what is the age of onset
- Increase bone thickness affecting face, jaw, hands, feet
- Typically ages 30-50 years old
what is the second most common metabolic disease
paget disease
What is paget disease
- Progressive disorder
- Excessive bone resorption and formation
- High bone turnover with little structural stability
- Adult disease equally affecting men and women -Systemic disease
Paget disease Musculoskeletal manifestations
Pain Fractures Arthritis Stiffness Deformaities
