30 - orthopedics MCQs - 11 to 20

11 - blount's disease ?

a - genu valgus
b- tibia vara
c- flat foot
d- genu recurvatum

answer is a . knock knee or genu valgus .


----------------------------------------------------------------------------------------

12 - bunion is ?

a - exostosis
b - adventitious bursitis lateral to first metatarsal
c - base of 1st metatarsal
d - head of first metatarsal

answer is b .

------------------------------------------------------------------------------

13 - distal interphalangeal joint is not involved in ?

a- rheumatoid arthritis
b- psoriatic arthritis
c- multicentric histiocytosis
d- neuropathic arthropathy

answer is A. the proximal interphalangeal joints are involved in rheumatoid arthritis and the nodes formed in these PIP s are called bouchard's nodes . my mnemonic BRA . :-)

-----------------------------------------------------------------------------------------------

14 - syme's amputation involves which joint ?

a- ankle
b- midtarsal
c- tarsometatarsal
d- all of the above

answer is A .

----------------------------------------------------------------------------------------------

15 - march fracture most often involves ?

a- 1st metatarsal
b- 2nd metatarsal
c- 3rd metatarsal
d- fibula

answer is both b and c . any of the 2nd and 3 rd metatarsal may be involved .

-----------------------------------------------------------------------------------------------------------

16 - diaphyseal tumors- ewing's tumor , osteiod osteoma , adamantinoma , enchondroma

--------------------------------------------------------------------------------------------------------------

17 - epiphyseal tumors - osteoclastoma , chondroblastoma

------------------------------------------------------------------------------------------------------------

18 - metaphyseal tumors - osteosarcoma , chondrosarcoma , osteochondroma , aneurysmal bone cyst , unicameral bone cyst , osteomyelitis .

---------------------------------------------------------------------------------------------------------

19 - most common site of osteogenic sarcoma ?

a- femur upper end
b- femur lower end
c- tibia upper end
d- tibia lower end

answer is b . femur lower end .

-------------------------------------------------------------------------------------------------------------------

20 - soap bubble appearance is the radiological feature of ?

a- osteoclastoma or GCT
b- osteosarcoma
c- osteoid osteoma
d- chordoma

answer is a .

18 - primary malignant bone tumors

What are the common primary malignant bone tumors?

• Osteogenic sarcoma
• Ewing's sarcoma
• Fibrosarcoma
• Chondrosarcoma

Primary bone tumors are rare, accounting for less than 1% of all malignant tumors.

What are the useful imaging modalities to investigate primary bone tumors?

• Plain radiographs
  • Plain radiographs can often predict the probable histology of a potentially malignant bone lesion.
• MRI
  • MRI is the imaging procedure of choice to evaluate primary bone tumors.
  • MRI is invaluable in surgical planning as it demonstrates the intraosseus and soft tissue involvement of the tumor and tumor extension.
  • MRI is also helpful in evaluating possible malignant degeneration of osteochondromas by allowing accurate measurements of the cartilage cap.
• CT
  • CT scans are generally less useful than MRI for assessing primary bone tumors.
  • CT is helpful in defining the integrity of the cortex and distribution of calcification.

What are the imaging findings of primary bone tumor?

• Osteogenic sarcoma
  • Destruction of bone
  • Sunburst appearance
  • Periosteal elevation
    • MR
    • Bone scan
  • Sclerosis

Osteogenic sarcoma fibula Destruction of bone with sunburst appearance.

Osteogenic sarcoma Tibia Sunburst appearance Aggressive periosteal reaction Sclerosis

Osteogenic sarcoma tibia Black Arrowheads : Destroyed cortex.

Osteogenic sarcoma tibia

• Chondrosarcoma
• Mass with calcification
• On plain radiographs, chondrosarcoma is a fusiform, lucent defect with scalloping of the inner cortex and periosteal reaction.
• Extension into the soft tissue may be present as well as punctate or stippled calcification of the cartilage matrix.

Chondrosarcoma Inferior ramus of pubis Calcified cartilaginous mass arising from a flat bone in a patient with unfused epiphyses.

Chondrosarcoma MR: White arrows : Mass with calcification. Arrowhead is pointing to femur.

• Ewing's Tumor
  • Lytic lesion
  • "Onion peel" appearance of periosteal reaction

Ewings Sarcoma Femur Arrow : Lytic lesion Arrowhead: "Onion peel" appearance of periosteal reaction.