Bones, Joints and Soft Tissue

Question 1

MC skeletal dysplasia and MAJOR cause of dwarfism

Answer 1

ACHONDROPLASIA

Question 2

MC lethal form of dwarfism

Answer 2

THANATOTROPHIC DYSPLASIA

respiratory insufficiency - USUAL CAUSE OF DEATH

Question 3

MC inherited disorder of CT

AD

extreme skeletal fragility d.t. TOO LITTLE BONE

Answer 3

OSTEOGENESIS IMPERFECTA

TYPE I COLLAGEN

TYPE OI - MOST LETHAL

Question 4

Impaired osteoclast function –> EXCESSIVE BONE FORMATION

WOVEN deposited bone

Answer 4

OSTEOPETROSIS (MARBLE BONE DISEASE)

(-) medullary canal
ERLENMEYER FLASK DEFORMITY

Question 5

MC skeletal malignancy

Answer 5

METASTASIS

Question 6

MC primary malignant bone tumor

Answer 6

OSTEOSARCOMA

Question 7

2nd MC malignant matrix producing tumor of the bone

Answer 7

CHONDROSARCOMA

Question 8

2nd MC group of bone sarcomas in CHILDREN

Answer 8

EWING SARCOMA

Question 9

MC BENIGN BONE TUMOR

adolescence early adulthood

SOLITARY

METAPHYSIS

KNEE

Answer 9

OSTEOCHODNROMA

Question 10

Increased but disordered and structurally unsound bone

BONE PAIN

axial, skeleton, proximal femur

Answer 10

PAGET DISEASE (OSTEITIS DEFORMANS)

COMPLICATIONS:
high output failure - Pagetic bone as AV shunt
OSTEOSARCOMA AND FIBROSACROMA - MOST DREADED

mosaic pattern of lamellar bone
jigsaw puzzle like appearance d.t. cement lines

Question 11

FRACTURE HEALING

Answer 11

0-2 weeks - PROCALLUS

2-3 weeks - BONY CALLUS (WOVEN)

3 weeks - months - LAMELLAR bone formation

Question 12

< 2 cm

APPENDICULAR skeleton - femur or tibial

relieved by NSAIDs

MARKED reactive bone formation

Answer 12

OSTEOID OSTEOMA

radiofrequency ablation

Question 13

> 2 cm

AXIAL skeleton - posterior spine

NOT relieved by NSAIDs

Answer 13

OSTEOBLASTOMA

en bloc excision

Question 14

METAPHYSIS

CODMAN triangle - periosteal lifting
SUNBURST appearance - infiltrative borders

Answer 14

OSTEOSARCOMA

lace like pattern
broad sheets, primitive trabeculae

Question 15

Benign tumor of HYALINE cartilage

20-50

METAPHYSIS

Answer 15

CHONDROMA

Ollier
Maffuci

Question 16

2nd MC group of bone disorders in CHILDREN

<20 y/o

DIAHYSIS (femur)

(+) systemic symptoms

Answer 16

EWING SARCOMA

lytic lesion
ONION SKIN - periosteal reaction

MICROSCOPIC:
uniform, small, round blue cells
scant, clear cytoplasm
HOMER WRIGHT ROSETTES

Question 17

BENIGN but LOCALLY AGGRESSIVE

INCREASED RANKL levels –> increased bone resorption

3rd-5th decade

EPIPHYSIS

Answer 17

GIANT CELL TUMOR (OSTEOCLASTOMA)

Question 18

Benign tumor that shows features of localized developmental arrest of bone

CHINESE CHARACTER - curvilinear trabeculae of woven bone

NO OSTEOBLASTIC RIMMING

Answer 18

FIBROUS DYSPLASIA

ASSOCIATED DISEASES:
Mazabraud syndrome - polyostotic FD + soft tissue myxomas

McCune-Albright Syndrome - polyostotic FD + Cafe au lait spots + precocious puberty

Question 19

Mechanical injury to articular cartilage

WEIGHT BEARING JOINTS - knees, hips

cartilage degeneration and fragmentation
BONE EBURNATION
OSTEOPHYTES
subchondral cysts
minimal inflammation

Answer 19

OSTEOARTHRITIS

BOUCHARD nodes - PIP
HEBERDEN - DIP

Question 20

Autoimmunity

cartilage destruction caused by CD4 T cells and antibodies

SMALL JOINTS OF FINGERS –> MULTIPLE JOINTS

PANNUS
severe chronic inflammation
ANKYLOSIS
rheumatoid nodules

EXTRA-ARTICULAR INVOLVEMENT

(+) systemic symptoms

Answer 20

RHEUMATOID ARTHRITIS

RHEUMATOID FACTOR

ANTI-CITRULLINATED PEPTIDE ANTIBODY

SWAN NECK
BOUTONNIERE

Question 21

usually MONOARTICULAR

1st MTP of the BIG TOE - MC joint involved

MORE INTENSE inflammation

Answer 21

GOUT

monosodium urate
NEEDLE shaped
NEGATIVELY birefringent (YELLOW)

Question 22

mono or polyarticular

KNEE - MC

Answer 22

PSEUDOGOUT

calcium pyrophosphate dihydrate
RHOMBOID
POSITIVELY birefringent (BLUE)

Question 23

Pathognomonic hallmark of gout

Answer 23

TOPHI

Question 24

MC subtype of rhabdomyosarcoma

Answer 24

EMBRYONAL

mixture of primitive round and spindle cells

SARCOMA BOTYOIDES - BEST PROGNOSIS