Musculoskeletal

Question 1

Multinucleated giant cells residing in Howship lacunae

Answer 1

Osteoclasts

Question 2

Backbone of bone matrix is made up of

Answer 2

type I collagen

Question 3

Woven bone

Answer 3

Collagen is deposited randomly (fetus, growth plates)

Question 4

Lamellar bone

Answer 4

Collagen is deposited in an orderly fashion

Question 5

Osteogenesis Imperfecta

Answer 5

deficiency in synthesis of type I collagen

Question 6

blue sclera, small misshapen yellow teeth, deafness

Answer 6

Osteogenesis Imperfecta

Question 7

Type I (Osteogenesis Imperfecta Tarda)

Answer 7

acquired mutation, mild

most common form, fractures in early childhood, XR shows old Fx

Question 8

Type II (Osteogenesis Imperfecta Congenita)

Answer 8

rare inherited, Fx & bone malformations at birth

Question 9

Death in osteoporosis pt is likely d/t

Answer 9

pneumonia and PE

Question 10

Osteoporosis

Answer 10

imbalance between bone resportion and formation ↑porosity of bones

Question 11

2 Types of Osteoporosis

Answer 11

age-related (low osteoblast Fx)

postmenopausal (high osteoclast Fx)

Question 12

Osteoporosis S/S

Answer 12

fractures of the distal forearm, vertebrae or proximal femur, compression microfractures, lumbar lordosis, kyphoscoliosis

Question 13

Osteoporosis Histology

Answer 13

excessive but proportional reduction in both mineral and matrix phases of bone

Question 14

Osteopetrosis

Answer 14

osteoclast dysfunction and diffuse skeletal sclerosis

Question 15

Osteopetrosis defect

Answer 15

defect in carbonic anhydrase II –> blocked matrix solubilization and resorption

Question 16

Erlenmeyer flask deformity

Answer 16

Osteopetrosis

Question 17

Malignant Osteopetrosis S/S

Answer 17

HSM d/t extramedullary hematopoiesis, mild cranial nerve deficits

Question 18

Paget Disease (Osteitis Deformans)

Answer 18

hereditary disease of osteoclast dysfunction and matrix madness (high osteoclast Fx -> burn-out -> high osteoblast Fx)

Question 19

Paget Disease (Osteitis Deformans) cause

Answer 19

fifth decade, may be d/t paramyxoviruses

Question 20

Paget Disease (Osteitis Deformans) affects

Answer 20

long bones, pelvis, spine, skull, with bone becoming thick, soft, and porous

Question 21

Paget Disease (Osteitis Deformans) Histology

Answer 21

mosaic pattern of lamellar bone

Question 22

thick porous skull

Answer 22

Paget Disease

Question 23

Paget Disease

Answer 23

Leonine facies (leontiasis ossea), skull invagination (platybasia), and femur bowing

Question 24

Increased hat size

Answer 24

Paget Disease

Question 25

Paget Disease bone findings

Answer 25

light, soft, porous, ossified, sclerotic bone

Question 26

Paget Disease

Answer 26

increased risk for osteosarcoma

Question 27

Rickets & Osteomalacia

Answer 27

vitamin D deficiency or disturbance in Vit D metabolism

Question 28

rosary bead formation at costochondral jxn

Answer 28

Rickets

Question 29

Long standing hyperparathyroidism can lead to

Answer 29

osteitis fibrosa cystica

Question 30

Osteonecrosis

Answer 30

ischemia → infarction of bone and marrow

Question 31

Causes of Osteonecrosis

Answer 31

fracture, thrombosis, embolism, blood vessel injury, ↑intraosseous pressure

Question 32

Medullary infarcts

Answer 32

infarcts of cancellous bone and marrow, but NOT cortex (SILENT)

Question 33

Subchondral infarcts

Answer 33

involve bony plates and epiphysis, but spare the cartilage

Question 34

Osteomyelitis

Answer 34

hematogenous spread, majority of cases are d/t S. aureus

Question 35

Osteomyelitis IN A SICKLE CELL pt

Answer 35

Salmonella

Question 36

Osteomyelitis Histology

Answer 36

Bone fragment becomes devitalized and necrotic (sequestrum) + sleeve of reactive bone at periphery (involucrum)

Question 37

Tuberculous osteomyelitis often involves

Answer 37

thoracic/lumbar spine (Pott’s disease)

Question 38

Tuberculous osteomyelitis

Answer 38

miliary TB

Question 39

Osteoma

Answer 39

benign bone tumor, face, Gardner Syndrome

Question 40

Osteoid Osteoma S/S

Answer 40

painful tumors, release PGE2, pain relieved by aspirin

Question 41

Osteoid Osteoma Histo

Answer 41

radiolucent nidus surrounded by densely sclerotic bone

Question 42

Osteoid Osteoma affects

Answer 42

femur & tibia

Question 43

Osteoblastoma S/S

Answer 43

dull, achy pain that does NOT respond to salicylates

Question 44

most common PRIMARY malignancy of bone

Answer 44

Osteosarcoma

Question 45

most osteosarcomas arise in

Answer 45

long bones (near knee)

Question 46

Osteosarcoma genetic link

Answer 46

associated with p53 and RB mutations

Question 47

Osetochondroma

Answer 47

cartilage capped outgrowth near epiphyseal growth plate of long tubular bones

Question 48

Chondroma

Answer 48

benign hamartomatous tumors composed of hyaline cartilage

Question 49

Ollier disease

Answer 49

multiple endochondromas

Question 50

Chondroma typically affect

Answer 50

females, occur in 3rd-4th decade of life, metaphyses

Question 51

Fibrous Cortical Defect and Non-ossifying Fibroma

Answer 51

extremely common congenital defects in up to 50% of children older than age 2, b/l, multiple, most spontaneously regress

Question 52

Fibrous Cortical Defect and Non-ossifying Fibroma Histo

Answer 52

fibroblasts in pinwheel pattern

Question 53

Fibrosarcoma and Malignant Fibrous Histiocytoma Histo

Answer 53

malignant fibroblasts in “herringbone” pattern

Question 54

Ewing Sarcoma

Answer 54

highly malignant small round cell tumor, neural origin

Question 55

McCune Albright Syndrome

Answer 55

Fibrous Dysplasia

Question 56

Giant Cell Tumor (Osteoclastomas)

Answer 56

"soap bubble" appearance, aggressive benign, epiphyseal

Question 57

Myositis Ossificans

Answer 57

develop in athletic young adult in high contact sport following trauma; usually found in subcutis or muscle of proximal extremity

Question 58

Dupuytren contracture

Answer 58

palmar fibromatosis

Question 59

Peyronie disease

Answer 59

Penile fibromatosis

Question 60

rhabdomyosarcoma

Answer 60

most common variant is embryonal rhabdomyosarcoma