Musculoskeletal disorders Flashcards
What kind of disorder is dysostosis, and what are 4 of its overall/general features?
Congenital disorder. Developmental anomaly of bone
Abnormal mesenchymal migration
Defective ossification of fetal cartilage
Sporadic (isolated) or part of a syndrome
Homeobox gene alterations
What are 3 specific features of dysostosis?
Aplasia (absent or incomplete development, abnormal function)
Supernumerary digits
Abnormal fusion of bones
What is dysplasia?
Mutations interfere with growth or homeostasis (dwarfism)
What are the 2 general kinds of dysplasia?
Bone: osteodysplasia
Cartilage: condrodysplasia
What are 3 notable pathologies of dysostosis?
Klippel-fiel syndrome
Polydactyly
Syndactyly
What osteological features are noted with Klippel-fiel syndrome?
Idiopathic congenital fusion of any 2 cervical vertebrae
Sprengel’s deformity
What kind of mutations are found with osteogenesis imperfecta (AKA brittle bone disease), and what does it cause?
Mutations of type I collagen (alpha 1 or alpha 2 chains).
Abnormal collagen -> premature breakdown.
What anatomy is affected by ostegenesis imperfecta?
ECM of eyes, joints, inner ear bones, skin, teeth/
What is the range of severity with osteogenesis imperfecta?
Type I: normal lifespan
Type II: Lethal in utero
What 2 lethal conditions does type II osteogenesis imperfecta cause?
Cerebral hemorrhage, respiratory failure.
Abnormal collagen of sclera is attributed to what condition?
Type I O.I.
What secondary conditions are associated with Type I O.I?
Fractures, extremity bowing, scoliosis, ligamentous laxity (dislocations), hearing loss, fragility.
What kind of adjusting is specifically contraindicated by O.I.?
Extremity adjusting
What radiologic sign is associated with O.I?
Zebra stripe sign
What are children with O.I. normally treated with?
Bisphosphonates (cyclical).
What is the most common form of dwarfism?
Achondroplasia
With achondroplasia there is decreased cartilage synthesis, which leads to what?
Decreased growth plate expansion
What mutation is implicated in achondroplasia?
Fibroblast growth factor receptor (FGFR3) gene mutation
What specific issue does mutation of the FGFR3 gene cause?
Inhibits epiphyseal (growth plate) chondrocytes
What percent of achondroplasia cases are spontaneous?
75%
What percent of achondroplasia cases are autosomal dominant?
25%
What deformations are noticed with achondroplasia?
Short proximal extremities, lower extremity bowing, frontal bossing, midface hypoplasia (low nasal bridge).
What are some spinal features noted in achondroplasia?
Hyper lordosis and kyphosis at birth, bullet vertebrae, scoliosis, spinal stenosis (of foramen magnum and or spinal canal).
How can death occur in achondroplasia patients due to it’s effect on the spine?
Death: brain stem compression, cardiovascular abnormalities.
What is thanatophoric dwarfism?
Extremely small thorax and shortened leg bones. Perinatal respiratory failure.
T/F
Prognosis is generally very good for those with thanatophoric dwarfism
False, its fatal.
What condition is associated with trident hand?
Achondroplasia
T/F
Osteopetrosis is a singular condition that is rather common
False,
A GROUP of RARE genetic disorders.
What is the primary structural issue with osteopetrosis?
Decrease in osteoclast-mediated bone resorption.
What is osteopetrosis AKA?
Skeletal sclerosis (“stone-like” bone).
What kind of injury occurs more frequently with osteopetrosis?
Fractures
Foraminal stenosis can occur with osteopetrosis, which can lead to what kind of nerve issues?
Cranial nerve palsies
With osteopetrosis, often the medullary cavity fills which leads to which 4 problems?
Leads to deranged hematopoiesis, which then can cause hepatospenomegaly, recurrent infections, anemia.
What is the treatment for osteopetrosis?
Stem cell replacement
What are some radiographic findings associated with osteopetrosis?
No medulla, erlenmyer flask deformity (forearm bones).
What is the most important form of osteopenia?
Osteoporosis
What is happening to bones with osteoporosis?
imbalance of osteoblast/clast homeostasis leading to decrease in bone bone mass = increase porosity.
What are the 2 major categories of osteoporosis?
Localized (disuse)
Generalized to entire skeleton
With osteoporosis that is generalized to the entire skeleton, what are the two types?
Primary: MC type, senile, post-menopausal
Secondary: various causes - neoplasia, hyperparathyroidism, nutrient deficiency, drug exposure (corticosteroids decreasing bone mineralization), alcohol, smoking.
What kind of bone done osteporosis MC affect, and where is it mostly discovered?
Spongy (trabecular/cancellous) bone. Thinned cortex.
Vertebral bodies, femoral neck, calcaneus.
T/F
Primary osteoporosis is not age related
False. It’s senile - thus age related.
What decreases noticeably with primary (senile) osteoporosis?
GF activity, osteoblast activity. 0.5% bone loss/year.
What stays about the same in primary (senile osteoporosis)?
Osteoclast activity
In secondary (post-menopausal) osteoporosis, what is the main causal factor of bone loss?
Decrease in estrogens.
What percentage of female osteoporosis patients are postmenopausal?
50%
What kind of supplementation is important for dealing with osteoporosis or preventing it?
Ca++ and vit D supplementation (MC females are deficient).
T/F
Osteoporosis patients are asymptomatic until skeletal fragility is detected?
True
What are the MC fractures associated with osteoporosis?
Vertebral compression fx (thoracolumbar)
Femoral neck fracture
With vertebral compression fractures (in osteoporosis patients) What are some secondary issues associated?
Dowager’s hump, kyphoscoliosis
Pneumonia
What potentially life threatening issue could arise with a femoral neck fracture in osteoporosis patients?
Pulmonary emboli
What is a treatment option for secondary (post-menopausal osteoporosis)? What are the risk factors associated with these treatments?
Estrogen therapy.
Increase risk of endometrial and breast cancers.
Increase risk for DVT
T/F
X-ray is a sufficient diagnostic tool for osteoporosis.
False,
X-rays are not sensitive enough. Requires 30 - 40% decrease in bone mass to detect.
Besides physical activity, Ca and vit D supplementation, what is another beneficial treatment for general osteoporosis?
Antiresorptive pharmacologic agents: bisphosphonates.
Paget’s disease is AKA
Osteitis deformans
What are the 3 phases of Paget’s disease?
Lytic phase
Mixed lytic and blastic phase
Sclerotic phase (exhaustion of cellular activity)
What are 2 primary finding with Paget’s disease?
Regional osteoclastic activity
Excessive bone formation (disorganized lamellar bone which leads to enlarged, fragile bones).
What is the diagnosis for Paget’s disease?
Increased serum alkaline phosphatase (byproduct of osteoblast activity).
T/F
Paget’s disease is MC shrouded with an array of symptomatology?
False,
MC asymptomatic (70-90%). Incidental X-ray finding, relatively benign.
T/F
Paget’s disease is becoming less and less severe?
True
What is the MC features of Paget’s disease?
Bone pain, neck & back.
What are 3 other features of Paget’s disease?
Osseous deformation, Fx, calor (increased vascularity)
Nerve compression: headache, visual/auditory
What percentage of cases of Paget’s disease transition into sarcoma?
1%. Poor prognosis
With Paget’s disease what is MC, solitary or multiple lesions?
Multiple
80% of cases of Paget’s disease lesions involve which areas?
Pelvis, sacrum, skull
What kind of fractures and bony abnormalities are noted with Paget’s disease?
Chalkstick fx. Bowing
What is the treatment for Paget’s disease?
Bisphosphonates (intended to slow lytic phase)
What kind of cytological finding is associated with Paget’s disease?
Mosaic “jigsaw” pattern.
What radiographic sign is associated with Paget’s disease?
Ivory verterbra sign.
What generally happens to bone with vitamin D deficiency, and how?
Defective mineralization. Hypocalcemia -> PTH -> demineralized bone
What is rickets?
Poor growth plate mineralization (children)
What is osteomalacia?
Remodeled bone is undermineralized
What does osteomalacia look like in adults?
Mild, similar to osteoporosis (fx). Associated with hyperparathyroidism.
What does the parathyroid gland do?
Secretes PTH which maintains serum Ca++
What is characteristic of primary hyperparathyroidism?
autonomous PTH production
What is characteristic of secondary hyperparathyroidism?
Renal failure (mild…???)
What is the most common cause of excessive PTH secretion?
80% from adenoma
What is the Dx for hyperparathyroidism?
Hypercalcemia, parathyroid immunoassay
What is the MC non malignant cause of hypercalcemia?
Hyperparathyroidsm
T/F
> 50% of people with hyperparathyroidism are asymptomatic
True
What is happening on a cytological level with hyperparathyroidism?
Excessive osteoclast activity impacts skeletal homeostasis causing resorption of cortical and trabecular bone.
What kind of neoplasm is associated with hyperparathyroidism?
“Brown tumor”
What 3 radiologic signs are associated with hyperparathyroidism?
Rugger jersey spine, salt & pepper skull, sub-periosteal resorption (eating away at the middle phalanges of the fingers).
What are some widespread features of hyperparathyroidism?
Bone pain, fx, deformation, kidney stones, fatigue, nausea, anorexia, decreased cognition.
What is the tx for hyperparathyroidism?
Drinking water, lots of physical activity, avoiding diuretics. Reversible with normalized PTH levels.
What are the 7 types of fractures?
Complete/incomplete (MC children) Closed: overlying skin intact Compound: overlying skin is intact Compound (open): Skin is ruptured Comminuted: fragmented, splintered Displaced: distal segment is malaligned Pathological fx: site of disease (brown tumor, bone cyst, tumor) Stress fx: develops over time (develops over time)
Where are stress fractures MC?
Legs and feet
What events mark the first week of fx repair?
Ruptured vessles -> fibrin mesh -> inflamm cells and fibroblasts -> soft tissue callus, noncalcified.
What events mark the second week of fx repair?
Woven bone -> chondroblasts
What events mark the 6-8 week period and beyond of fx repair?
Endochondral ossification -> bony callus. Lifelong remodeling.
What are 6 reasons for delayed healing?
Nonunion: large callus formation Comminuted fx Inadequate immobilization (disrupts callus formation) Infection (MC occurs with compound fx Nutritional deficiencies Advanced age
What are the MC causes of AVN (5)?
Corticosteroids, embolism (bends, sickle cell), vasculitis, irradiation, idiopathic
T/F
AVN is always painful
False,
Can be asymptomatic or painful
What subchondral areas are especially prone to AVN?
Knee, hip, shoulder, wrist, ankle.
What is the eventual new bone growth after AVN called?
Creeping substitution
What is AVN aka?
Osteonecrosis
What is joint AVN aka?
Osteochondritis dissecans
What are the 2 major types of AVN?
Subchondral or medullary
What is osteomyelitis?
Bone marrow inflammation (infection). Leukocytes destroy bone.
What is the most common form of osteomyelitis?
Acute
What are the 3 modes of infx with osteomyelitis?
Hematogenous (sepsis) MC Adjacent infection (from joint or other tissue) Traumatic implantation (from surgery or compnd fx - iatrogenic).
What are the major symptoms of osteomyelitis?
Acute fever, malaise, throbbing pain
T/F
With osteomyelitis the agent causing the infx is mostly identifiable
False,
50% unidentifiable
What organism is responsible MC for pyogenic infx in osteomyelitis?
Staphylococcus aureus
What is the Dx for pyogenic osteomyelitis?
Radiography, blood culture, biopsy
What is the involucrum?
Reactive/woven lamellar bone surrounding infected bone
What is the sequestrum?
Dead bone at the site of infx.
What is the draining sinus?
Ruptured periosteum leads to an abcess in the surrounding soft tissue.
What is tuberculosis osteomyelitis AKA?
Skeletal TB
Where and among whom is skeletal TB MC?
Developing countries. In USA: immigrants and immunocompromised
What are 3 features of TB osteomyelitis?
Caseous granulomas.
Bony destruction
Severe deformation
How does skeletal TB spread?
Hematogenous (MC), lymphatic
What is associated with a multifocal spread of TB osteomyelitis?
Immunodeficiency
What is associated with solitary spread of TB osteomyelitis?
Long bones, vertebrae
What is a famous condition of solitary spread TB osteomyelitis, and what does it cause?
Pott’s disease. Neurologic deficits
What is MC secondary mets to bone or primary bone tumors?
Secondary mets to bone
What are general features of bone tumors?
Bone pain, generally increases (MC), pyrexia, cachexia, anemia, pathologic fx, unexplained bony mass (superficial)
What are some characteristics of low back pain from cancer?
>50 years old History of cancer Unexplained weight loss Back pain not alleviated with bed rest Failure to improve/pain duration >1 month.
What 3 characteristics of low back pain are indicative of cancer?
> 50 years old, Hx of cancer, cachexia
T/F
Malignant bone tumors are MC than benign?
False,
Benign is MC
What are the 2 MC bone tumors?
Matrix, and fibrous producing tumors.
What are the 2 MC benign bone tumors?
Osteochondroma
Fibrous cortical defects
What are the three primary bone cancers?
Osteosarcoma
Chondrosarcoma
Ewing’s sarcoma
When do bone tumors develop and in what manner?
Early development (<40 yrs), benign, asymptomatic
Where do bone tumors MC develop?
Long bones of extremities.
What age range and body part do osteosarcomas develop?
10-20 years old. Knee
What age range and body part do osteomas develop?
40-50, facial bones/skull
What are the 3 types of bone forming tumors?
Osteoma
Osteoid osteomo and osteoblastoma
Osteosarcoma
What is an osteoma?
Developmental anomaly. Very similar to normal bone
What are some features of osteomas?
Exophytic, hard, superficial, solitary, slow growing.
Where do osteomas MC develop?
Head (skull/facial) & neck.
T/F
Osteomas are MC found in young adults
False
Middle aged (40-50 yrs).
What are 3 noted physical problems associated with osteomas
Cosmetic
Sinus obstruction
Local mechanical problems
T/F
Osteoid osteomas and osteoblastomas are malignant and MC in females?
False,
Benign. MC in males
What kind of leasion is noted with OO and OB?
Round-to-oval lesion. Near cortex, well-circumscribed. Central “nidus”
What is a “rim of sclerosis” MC in?
OO
What kind of pain is associated with OO and OB?
Localized nocturnal pain
What is larger, OO or OB?
OB
Where are OO and OB found?
Cortex of long bones (OO) Vertebral processes (OB)
What is different between the pain elicited by OO and OB?
OO: pain relieved by aspirin. Well localized
OB: pain unrelieved by aspirin. Mild and poorly localized.
What percentage of diagnosed primary bone cancers are osteosarcomas?
20%
Who is at the greatest risk for osteosarcomas?
Adolescent males
What are the features of osteosarcomas of older age (>40)
Co-morbid bone pathology (Paget’s disease, AVN, irradiation)
What locations do osteosarcomas affect?
Metaphysis of bones. Hip, knee, shoulder,
What kind of lesion is associated with osteosarcomas?
Large, mixed lytic and blastic lesions.
With bone tumors, what genes are MC mutated?
RB or TP53 gene
What aspect of the bone is destroyed with osteosarcomas?
Periosteum, medulla
What 3 radiologic features are associated with osteosarcomas?
Spiculations, sunburst, codman triangle
What serves as a 1000x increase in risk for osteosarcomas?
Retinoblastoma syndrome
What is the long-term survival rate for typical (primary) osteosarcoma (affecting 10-20 yr olds)
60 - 70%
What is the survival rate for secondary osteosarcomas?
Usually fatal
What 2 treatments are MC for osteosarcomas?
Amputation (limb salvage therapy)
Chemotherapy
What are the two kinds of cartilage-forming tumors?
Hyaline
Myxoid
Can be malignant or benign. MC benign
What is osteochondroma AKA?
Exostosis
What is an osteochondroma?
Benign, hyaline cartilage capped outgrowth
What are the 2 types of osteochondromas?
Solitary (MC): sporadic, adolescents/young adults
Multiple hereditary osteochondromas: Genetic (mutated TSG’s) childhood onset.
Where do osteochondromas arise?
On metaphysis of long bones (near growth plate). Knee (MC), pelvis, scapula, ribs, hands/feet.
T/F
Osteocondromas are rare after skeletal maturity
True
What are some features of osteochondromas?
Cortex merges with host bone (could be painful)
Slow growing
Sessile or pedunculated
What are the 2 types of chondromas?
Enchondroma: medullary
Juxtacortical chondroma: bone surface
What is affected by solitary chodroma lesions?
Metaphysis, tubular bones of hands and feet.
What is the name of the condition characterized by multiple chondroma lesions?
Ollier disease. AKA multiple endochondromas or endochondromatosis
T/F
Ollier disease is bilateral
False
Unilateral
What color are chondroma lesions?
Gray-blue translucent (hyaline) nodules
T/F
Chrondromas represent 10% of all benign bone tumors?
True
What sign is indicative of a chondroma?
Ring of sclerosis “O ring” sign.
What features are noted of the center of chondroma lesions?
Possible osteonecrosis (irregular opacification).
T/F
Chondromas are MC asymptomatic
True
Where is the most common place for solitary endochondromas of the hand?
Proximal phalanges
Who is most at risk for chondrosarcomas?
40-60 yr old males
What locations are affected by chondrosarcomas?
Intramedullary (MC) or juxtacortical: pelvis, shoulder, ribs, prox. femur.
Rare in distal extremities
What special lesion is associated with chondrosarcomas?
Expansile “glistening mass” - painful. Neoplastic hyaline and myxoid cartilage (may thicken or erode cortex).
What is the MC form of chondrosarcomas?
Low grade: slow growing, small. 80-90% 5 year survival. Reactive THICKENING of cortex
What are the features of high grade chondrosarcomas?
Cortical erosion, large, soft tissue mass of cartilaginous tissue. 70% mets (MC lungs) or other bones. Poor prognosis
What is the tx for high grade chondrosarcomas
Wide excision, chemotherapy
What are fibrous cortical defects and nonossifying fibromas?
Benign lesions of macrophages and fibroblasts. Thought to be reactions to periosteal injury.
T/F
FCD’s and NOF’s are neoplastic
False
What lesion is larger, FCD of NOF?
NOF
Where are FCD’s and NOF’s found?
Knee: distal femur (MC), proximal tibia
T/F
FDC’s and NOF’s are usually not painful
True
What gives a greater risk for fracture: NOF or FDC?
NOF
What is the treatment for NOF and FDC?
Self resolve within 2-3 years. Differentiate into cortical bone
