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Flashcards in Mahoney case III Deck (48):

2 X-ray stress tests to specifically test Lisfranc's

- abduction stress test: step off of the 2nd met intermediate cuneiform joint

- adduction stress test: 1st met-cuneiform and 2nd met cuneiform widen


What is found with the adduction and abduction stress tests?

- abduction stress test: step off of the 2nd met intermediate cuneiform joint

- adduction stress test: 1st met-cuneiform and 2nd met cuneiform widen


Osteoporosis: imaging exams for diagnosis (4)

-Quantitative Ultrasound scanner


-Quantitative ultrasound scanner

DXA: dual photon X-ray absoptiometry. Gold standard to assess bone mineral density and detect early osteo.
----2 energy X-rays shot at the bone and subtract the soft tissue component

VFA: x-ray taken of the spine, looking for an old fracture of the vertebra. Patient with the correct demographic features and positive VFA or IFA means positive for osteoporosis.

IFA: same as VFA

Quantitative Ultrasound scanner: popular prescreening tool to rule out osteoporosis. Need a DXA evaluation in order to rule in


Definition of T-scores

Standard deviation that shows how much a patient's bone density is higher or lower than the bone density of a healthy 30 year old adult


Definition of Z- score

Standard deviation that compares patient bone density to what is normal in someone in their own age and body size.


T-score: use in what patient population

T-score used in older adults such as postmenopausal women and men over 50


Z-score: use in what patient population

useful in children, teens, younger men and women still having periods


Normal T-score and Z-score

T-score: above -1 is normal

Z-score above -2 is normal



--normal value

-- Low bone density (osteopenia)


-Normal bone density: -1 and above

-Low bone density (osteopenia): between -1 and -2.5

-Osteoporosis: below -2.5


Non-pharmacological treatment options for osteoporosis (3)

-behavioral modifications: stop tobacco, alcohol, and caffeine consumption

-Balanced diet: adequate calcium and Vitamin D intake

-Regulatory exercise program


MOA for estrogen

control activity of osteoblasts and osteoclasts. Will keep osteoclast numbers low and low activity as well


MOA calcium

increased bone mineralization


MOA vitamin D

increases calcium absorption in the GI tract


MOA Calcitonin

hormone directly inhibits osteoclastic bone resorption


MOA bisphosphonates

bind permanently to mineralized bone surfaces and inhibit osteoclastic activity


MOA raloxifene

will inhibit trabecular and vertebral bone loss by blocking the activity of cytokines which stimulate bone resorption


Definition of FRAX

can be used as an assessment modality for the prediction of fractures on the basis of clinical risk factors


Wilson Katz: stress fracture Type I

-what will be seen on X-ray

fracture line with no evidence of endosteal callus or periosteal reaction

-will see a radiolucent line through bone


Wilson Katz: stress fracture Type II

-what will be seen on X-ray

focal sclerosis and endosteal callus (occurs in cancellous bone)

-Will see a radiosclerotic at the metaphysis (in the metaphysis of the heads and bases)


Wilson Katz: stress fracture type III

-What will be seen on X-ray

Periosteal reaction and external reaction. Will see this mainly on the shaft

-Will see a callus lump.


Wilson Katz: stress fracture type IV

mixed combo of type 1,2,3


Fundamentals of MRI physics.

TR and TE values for T1 and T2

T1: Short TR and short TE

T2:long TR and long TE


What are the fat image and water image in MRI

Fat image is T1

Water image is T2


Gadolinium and its use in MRI

it will identify acute inflammation and infection.

-Will improve visibility of inflammation, tumours, blood vessels and blood supply


What disease will Gadolinium cause (2)

-Nephrogenic systemic fibrosis

-Gadolinium retention (in the brain)


What is the "magic angle effect"

-An MRI artifact which occurs on sequences with a short TE.

- It is confined to regions of tightly bound collagen at 54.74 degrees from the main magnetic field and appears hyperintense, thus potentially being mistaken for tendinopathy


What are the 5 stages for hemorrhage



-Early subacute (2-7days)

-Late subacute (7-14days)

-Chronic (14-28 days)


What are the imaging characteristics of hyperacute stage

-isointense on T1 and isointense to hyperintense on T2.

- Due to intracellular oxyhaemoglobin


What are the imaging characteristics of acute stage

-T2 signal intensity drops. T1 remains intermediate to low.

-Due to intracellular deoxyhaemoglobin


What are the imaging characteristics of early subacute stage

-T1 signal gradually increases to become hyperintense.

- Due to intracellular methaemoglobin


What are the imaging characteristics of late subacute stage

-extracellular methaemoglobin leads to increase in T2 signal


What are the imaging characteristics of chronic stage

- periphery is low on T1 + T2.

-Center is isointense on T1 and hyperintense on T2.


Stages of bone healing and time line (5)

1) Inflammation (1-4days): hematoma formation

2) Induction(day 1-?)

3) Soft callus (4-4weeks)

4) Hard callus (4 weeks- 4months)

5) Remodeling(4 months-2 years)


What effect does pH and O2 have on bone healing

- pH: better when alkyline

-High O2 better early on in bone healing

-Low O2 better later on in bone healing


Hardcastle classification for Lisfranc's injuries

Type A: Total displacement

A1: Lateral displacement

A2: Dorsoplantar displacement

Type B: Partial displacement

B1: Medial dislocation 1st met

B2: Lateral dislocation lesser mets

Type C: Divergent (1st met medially while lesser mets go laterally)

C1: 1st met displaced medially with some lesser mets laterally displaced

C2: 1st met displaced medially with all lesser mets laterally displaced


Myerson classification of Lisfranc's injuries

Type A: Total displacement in any plane or direction

Type B1: Medial displacement of 1st met

Type B2: Lateral displacement of 1 or more lesser mets

Type C1: Partial displacement of 1st met medially and lesser mets laterally

Type C2: Total displacement with a divergent pattern with total incongruity


AP X-ray findings for Lisfranc's ligaments

flex sign: avulsion at base of 2nd met cuneiform

step off: widening of the 1st interweb space


Oblique X-ray findings for Lisfranc's ligaments

lateral margins of 2nd met-cuneiform and 3rd met-cuneiform should align


Lateral X-ray findings for Lisfranc's ligaments

will look for dorsoplantar subluxation or angulation and loss of medial plantar arch

- medial plantar archis determined by medial cuneiform and 5th met


Nunley Classification of Lisfranc's injuries (3stages)

Stage I: pain at the Lisfranc complex and were nondisplaced radiographically, but demonstrates increased uptake on bone scan.

Stage II: M1-M2 diastasis 1-5mm greater than the uninjured foot but no loss to arch height
TX- operative

Stage III: More than 5mm M1-M2 diastasis and arch height loss
TX- operative


External bone growth stimulators (the two types)

Electrical stimulator and ultrasound stimulator


Electrical bone stimulator details

to stimulate need to use negative electric current.

-to resorb need to use positive electric current.


Ultrasonic osteogenesis stimulator detail

stimulates receptor of osteoblasts to start producing osteoprogenitor material

-not through the previously believed mechanism of mechanical stimulation


Sudeck atrophy

metabolic bone changes that occur with CRPS


Causes of Normocytic anemia (4)

Acute blood loss
Bone marrow failure
Chronic disease
Destruction (hemolysis)


Causes of Macrocytic anemia (8)

-Alcohol (liver disease)
-B12 deficiency
-Compensatory reticulocytosis
-Endocrine (hypothyroid)
-Folate deficiency/Fetus


Causes of Microcytic anemia (4)

Iron deficiency
Chronic disease
Sideroblastic anemia