Principles Flashcards
1
Q
What is the most common type of intimate partner violence?
What is the most common type of physical abuse?
A
Emotional abuse most common: 30.5%
Physical abuse 2nd most common: 8.5%
Sexual abuse: 3.3%
Of physical abuse:
Head/neck trauma most common
Orthopaedic injuries second most comon (sprains, fractures, dislocations, foot injuries)
2
Q
Grafting of burns should take place within what time frame?
A
Within 5 days
3
Q
In the aging population, what should the training regimen involve?
A
resistance
endurance
balance
flexibility
4
Q
What addidtional specieis do you have to cover for in fresh and saltwater contaminated open fractures?
A
Fresh
Aeromonas hydrophilia (G-)
Vibrio
Salt
Clostridia (tetanus)
Vibrio
5
Q
Virchow’s triad
A
Venous stasis
Hypercoaguable state
Endothelial injury
6
Q
What is the major arterial supply to gastrocs flap
A
Sural artery (for both medial and lateral)
7
Q
What is the term to define a loss of function resulting from an anatomic or physiologic derangement
A
Impairment
8
Q
What is the best route and dosing for postop analgesics in a morbidly obese individual?
A
IV patient controlled analgesia (PCA) based on ideal body weight (not actual)
Avoid subcutaneous/submuscular (poor blood supply –> increased infectiion risk)
9
Q
What anesthetics have an effect on neuromonitoring?
A
inhalational - affects both SSEP and MEP
neuromuscular blockage: MEPs only
10
Q
What is the immune response when transplanting fresh articular cartilage allograft?
A
There is none, even when unmatched
There is once you start adding in cells, like BM aspirate
11
Q
Mechanism of Tocilizuab
A
IL-6 antagonist
12
Q
Do acidic or alkaline burns penetrate deeper?
A
Alkali
13
Q
List 4 ways to optimize intra-operative cultures
A
No pre-op antibiotics
Bone and Soft Tissue Samples
>= 5 samples
Hold cultures for 10-14 days
14
Q
toughness
A
amount of energy per unit volume a material can absorb before failure
= area under the stress/strain curve
units: joules/m3
15
Q
When does braking time return to normal after:
knee arthroscopy
Surgical management of ankle fracture
After initiation of weight bearing following major lower extremity fracture?
A
knee arthroscopy: 4 weeks
Surgical management of ankle fracture: 9 weeks
After initiation of weight bearing following major lower extremity fracture: 6 weeks
16
Q
Stress Strain curve: Yeild strength
A
amount of stress necessary to produce a specific amount of permanent deformation
17
Q
Can a person drive with a simple forearm cast?
A
Yes (JAAOS 2013)
But not if the elbow is immobilized
18
Q
What percentage of patietns in fracture clinic have been victims of intimate partner violence:
Overall:
this year:
Specifically for this visit:?
A
Overall: 33% (1 in 3)
this year: 15% (1 in 6)
Specifically for this visit: 2% (1 in 50)
19
Q
Consequences of paralytic ileus (6)
A
abdominal pain
malnutrition
prolonged hospital stay
hospital readmission
bowel perforation
death
20
Q
Define neuropraxia
A
Disruption of myelin sheath only, causing focal conduction block
No wallerian degeneration
full recovery expected
21
Q
Higher Young’s modulus means what?
A
Young’s modulus of elasticity
Higher Young’s modulus = A stiffer material = more ability to resist deformation
22
Q
What percentage of women presenting to ER with injuries are a result of domestic violence?
A
Up to 35%
23
Q
What immunoglobulin does rheumatoid factor target?
A
IgG
It is an IgM that targets the Fc portion of IgG
24
Q
Criteria for Bisphosphonate Related Fractures
A
Major
- None or minimal trauma (fall from standin or less)
- Originates from lateral cortex & is transverse or short oblique in nature
- If complete, fracture extends through both cortices and may be associated with a medial spike (incomplete fractures only involve lateral cortex)
- Fracture is noncomminuted or minimally comminuted
- Localized periosteal or endosteal thickening of the latearl cortex is present at the fracture site (beaking or flaring)
Minor
- Generalized increase in cortical thickness of the femoral diphaysis
- Unilateral or bilateral prodromal sx (thigh pain)
- Bilateral incomplete or complete femoral diphyseal fractures
- Delayed fracture healing
Need 4/5 major. NO minor (they are just associations)
2013 American Society for Bone Mineral Task Force, as per JAAOS 2015
25
Ideal candidate for fresh osteochondral allograft?
Young (\<25)
Symptoms \< 1 year
They have better results and higher return to sport
26
2 muscles innervated by axillary nerve
Deltoid
teres minor
27
Ways to optimize for bone healing?
Provide mechanical stability and a favorable biologic environment
Tobacco cessation
glycemic control
nutritional optimization
* Vit D deficiency
management of metabolic and endocrine abnormalities
* thyroid
* parathyroid
* central hypogonadism
28
What is the only anticoagulation prophylaxis recommended by AAOS in all risks groups undergoing THA or TKA?
Pneumatic compression devices
29
Mixing what 2 metals has the highest risk of galvanic corrosion?
316L stainles steel and cobalt chromium (Co-Cr)
30
Nerve repair of what nerve has the best and the worst outcomes
Best: radial
Worst: peroneal
_The following nerves had excellent recovery potential:_
* the radial, musculocutaneous, and femoral nerves.
_The following nerves had moderate recovery potential:_
* the median, ulnar, and tibial nerves.
_The following nerve had poor recovery potential:_
* the peroneal nerve.
31
Name the 3 main triggers of bone erosion in RA:
Synovitis
Anti-citrullinated protein antibodies (Anti-CCP)
RANKL
32
What do you have to do post-op medication-wise in patient with CRF
Specifially analgesia, abx, DVT prophylaxis
Narcotics:
decrease dose
Hydromorphone: reduce to 25% and titrate
Morphine: none (max short term only)
Anticoagulatns:
Unfractionated heparin, warfarin, ASA, clopidogrel, argatroban OK - no dose adjustment
No: LMWH, fondaparinux, dabigatran
Antibiotics
Ancef:1-2g IV q24
33
Describe *updated* CANMEDS
Medical Expert
Professional
Communicator
Collborator
***Leader***
Health advocate
Scholar
(no more Manager)
34
Hysteresis
Energy dissipation
characteristic of viscoelastic materials
the loading curve does not follow the unloading curve
the difference between the two curve is the energy that is disspitated
35
In relation to TB arthropathy.
What is Phemister's Triad?
Juxta-articular osteopenia/osteoporosis
Peripheral osseous erosions
Gradual narrowing of joint space
36
What medication combined with MTX makes it more effective against RA?
Doxycycline
37
Components of WHO pre op sign in
Before induction of anesthesia
38
Plastic deformation
irreversible changes in shape to a material due to a load
material DOES NOT return to original shape when load is removed
39
Salt water open fracture. Treatment?
doxycycline and ceftazidime, or a fluoroquinolone
40
Mechanism of Etanercept:
TNF-alpha inhibitor
41
2 dDx for erosive arthritis
Inflammatory arthritis
TB - always think TB & ask about foreign travel
42
Kid steps on a nail at a cottage.
what is your initial magagement?
Tetanus
I&D in ER
No need for abx - tell them to return if any signs/symptoms
FYI: remember NEVER to give cipro to a kid - risk of tendon rupture
43
After contaminated needle stick, risk of:
HIV
Hep B
Hep C
HIV: 0.3%
Hep B: 37-62% (good thing we got our shots)
Hep C: 0.5-1.8%
44
2 factors/cytkines that promote differentiation into osteoclasts:
RANKL (releaesd by osteoblasts), M-CSF
45
Peroneus brevis flaps are good for:
distal 1/3 coverage leg
small defects only
46
Characteristics of an abused patient
Change in affect
Constantly seeking partner approval
Finding excuses to stay in treatment facility for prolonged period of time
Repeated visits to the emergency department
Significant time missed at work or decreased productivity at work
47
Define ICER
Incremental cost effectiveness ratio
Determines which intervention is more cost effective in a patient population
48
Define health utility
Reflects a patient's preference for a particular health state or health-related outcome in a single index number between 0 (death) & 1(perfect health)
49
When can a patient drive after THA?
4-6 weeks
50
Who should be screened for intimate partner violence?
Who should screen?
All women in a fracture clinic
Screening should be done by an IPV coordinator
(Sprague & Bhandari 2013)
51
Define axonotmesis
Disruption of myelin sheath and axon
Endoneurium is intact
leads to conduction block with wallerian degeneration
52
Managment of Anti-TNFa inhibitors perioperatively
Etanercept: discontinue 1-2 weeks prior, restart when wound is healed (2 weeks)
Rituximab: discontinue 2 months prior
All other: discontinue 1 month prior
53
Complications of transfusion (especially massive transfusion)
_thrombocytopenia_
_coagulation factor depletion_
stored blood contains all coag factors except V and VIII
DIC consequence of delayed or inadequate resus
_oxygenic affinity changes_
_Hypocalcemia_
side effects of hypocalcemia ® tetany, hypotension, arrhythmias
_hyperkalemia_
not a problem unless very large amounts of blood given quickly
_acid / base disturbances_
_hypothermia (frozed PRBCs – warmed to room temp)_
leads to tendency to cardiac dysrhymthmias
_ARDS/TRALI_
54
What antihypertensives should you hold preop?
ACE-I
ARB
55
Components of WHO Sign out
Before patient leaves OR
56
Best test for RA
Anti-CCP
Most sensitive and specific
57
Stress
intensity of an internal force
= force/area
units: Pascal's (Pa) or N/m2
58
What test is diagnostic for hypophosphatasia?
Increased urine phosphoethanolamine
59
What material is the most susceptible to crevice corrision?
316L stainless steel
60
Best way to size fresh osteochondral allograft for the knee?
AP x-ray
| (MRI are worse)
61
ARDS criteria
* acute, meaning onset over 1 week or less
* bilateral opacities consistent with pulmonary edema must be present and may be detected on CT or chest radiograph
* PF ratio
* “must not be fully explained by cardiac failure or fluid overload,” in the physician’s best estimation using available information — an “objective assessment“ (e.g. echocardiogram) should be performed in most cases if there is no clear cause such as trauma or sepsis.
(Berlin criteria)
62
Name a common location of fretting corrision
Head neck junction in THA
63
Important aspects of consent
Capacity
Disclosure (of material risks and benefits)
Demonstrate Understanding (synthesize, ask good questions)
Voluntary
64
Indications for thoracotomy in ATLS
Hemothorax \>1500mL initially
Hemothorax \>200-300mL/hr
Penetrating injury with PEA
65
Formula for absolute risk reduction
ARR = control event rate - treatment event rate
66
Sleep apnea has what effect post-op?
Increased complications, including
in hospital mortality
PE
wound hematoma/seroma
Can be diagnosed with STOP BANG (see pic)
JAAOS 2014
67
How does TXA work?
inhibits fibrinolysis via inhibition of activation of plasminogen
68
What is a thixotropic fluid?
It's viscosity decreases with increase rate of movement (ie with increasing shear)
Sorry..it was on an exam
69
List 4 occupational hazards to the pregnant or lactating woman in the orthopaedic OR:
Radiation exposure
Physical stress
Blood borne pathogens (HIV, HCV, HBV)
Harmful chemical (PMMA, inhalational anesthestics)
70
Treatment of CRPS
1st line:
Gentle PT, stretching
Medications: NSAIDs, anti-depressants, alpha blockers, CCBS, antidepressants, anticonvulsants, GABA agonists
Nerve stimulation: type II only
Operative
Surgical sympathectomy
Indicated in failed nonoperative management
71
The bending rigidity of the implant shown in Figure A is proportional to what power of the measured radius of the implant
The bending rigidity of a solid cylindrical pin is related to the fourth power of the pin’s radius. The bending rigidity of the implant shown in Figure A is proportional to what power of the measured radius of the implant
72
Bleeding risk in patients with Chronic renal fialure?
INcreased ris of BOTH bleeding and thrombosis
73
5 poor prognostic indicators in nerve injuries
Old \>54
Proximal nerve injury
* At level of wrist, 50% good recovery
Graft \>7cm
War injuryBlast:
* Large zone of injury or heavily contaminated
Surgery delayed \>18 months
74
Fasiculations: a sign of upper or lower motor neuron lesion?
Lower
75
List 4 principles of treating fractures through burned skin
_If fracture needs OR:_
Definitive treatment ideal
Through alternate skin incision if possible
If incision must be through burn, must do this within 48hrs
If \>48hrs (tissue will be colonized):
* Ex-fix (until wounds healed)
* Splint (until wounds healed)
* ORIF at the same time of wound debridement and skin grafting
76
How long is the consolidation phase of distraction osteogenesis technique?
2x transport
77
5 ways to decrease risk of injury with a tourniquet:
_Time:_
\< 2 hours generally safe
Deflation time: The more the better (at least 30 mins)
_Pressure_
\<200 mmHg in UE (or 50 above sBP)
\<250mmHg in LE (or 100 above sBP)
Best is to measure Limb Occlusion Pressure using commercially available devices
_Shape_
Wide
Conical
_Other_
Not using a tourniquet
Having 2 cuffs and alternating between them
Well padded
78
Post-op, what adjustment to post-op pain control will redheads need ?
Higher dosing
79
What levels of MAP and PaO2 are protective in spinal surgery/post spinal trauma?
MAP \> 85mmHg
PaO2 \> 60mmHg
80
3 main cytokines in RA
TNF-alpha, IL-1, IL-6
81
After frostbite, administration of what drug has been shown to decrease rates of amputation?
Tissue plasminogen activator
Thought that thrombosis after re-warming leads to necrosis/amputation
82
What is the most common cause of OM?
Staph aureus in all age groups and demographics (including IVDU)
83
What percentage of women have been abused in the last 12 months?
2013 PRAISE - Lancet/Multinational Study: 1/6
2011 PRAISE - JBJS **Ontario Only, smaller study =** 1/3
So I would say 1/6, bigger study.
\*\* Should say IPV rather than abuse. IPV includes physical, emotional and sexual.
84
What does the OTA & American College of Chest Physicians recommend as anticoagulation prophylaxis?
LMWH
| (JAAOS is wishy washy)
85
General principles of delivering bad news/news of complication:
Sit down 1 on 1 with patient
Find a quiet, non-rushed environment
Turn off pager and cell phone
Tell them what happened
Tell them what we will do:
* a. to correct the patient's problem
* b. to ensure that this will not happen again (patient's want to hear this)
Ask if they have any questions
86
T/F:
Most people lose weight after THA/TKA
False
Most people DO NOT lose weight after TKA
So the idea that we give people a TJA to help them lose weight is bullshit
87
Classificaiton of CRPS
Type I: CRPS without demostrable neve lesion
most common
Type II: CRPS with evidence of obvious nerve damage
88
For optimal wound healing, albumin should be:
\>3.0g/dL
89
Nerve repair spiel
I will aim for a tension free repair in a clean wound bed
90
Name 5 local and 5 systemic manifestations of using a tourniquet
**_Local_**
Post-operative swelling and stiffness
Delay in recovery of muscle power
compression neurapraxia
wound hematoma
Wound infection
Direct vascular injury
Bone and soft-tissue necrosis
Compartment syndrome
**_Systemic:_**
increased VP
arterial hypertension
cardiorespiratory decompensation
Cerebral infarction (CVA)
Alterations in acid-base balance
Rhabdomyolysis
DVT (controversial)
91
Contraindications to hyperbaric oxygen therapy
Chemo or radiation therapy
* pressure-sensitive implanted medical device:
* defibrillator, pacemaker, dorsal column stimulator, insulin pump
* Undrained pneumothorax
92
Define neurontmesis
Complete disruption of the nerve, including disruption of endoneurium
No recovery unless surgial repair performed
93
After burns, what level of urine output should be maintained?
at least 2mL/kg/hr
| (for 70kg man: 140mL/hr)
94
What medication has been shown to increase skeletal muscle regeneration and decrease fibrosis (in animal models)
Angiotension II Receptor blockers (Losartan)
95
What do you do after identifying a medical error?
Offer an apology to family/patient
Provide full disclosure (explain what happened)
Accept responsibility
Offer corrective steps to prevent recurrence
Document fully
Call CMPA
(an apology is NOT the same as accepting blame. You are sorry for what happened, not for doing something bad)
96
Define a neurologic level in SCI
Lowest level with normal sensation and 3/5 power
So the lowest normal level
If there is a lesion at L3, it would be an L2 level
In other words, an L2 level means everything below L3 is messed
97
What is the additional energy expediture for the following:
Transtibial amputation
Long transtibial amputation
Transfemoral amputation
Transtibial amputation: 25%
Long transtibial amputation: 10%
Transfemoral amputation: 65%
98
Name the CanMeds Components
Professional
Health advocate
Medical expert
Manager
Scholar
Communicator
Collaborate
"Please Help Me Memorize Stupid Canmeds Crap"
99
Who should be listed as an author on a research paper?
Each author should have participated sufficiently in the work, including:
Conception or design, or analysis and interpretation of data, or both
Drafting the article or revising it for critically important intellectual content
Final approval of the version to be published
\*participation solely in the collection of data does not justify authorship (ie can't be in it if you let your patient's take part)
100
Mortality rate of fat emboli syndrome?
15%
101
Contraindications to primary closure in open fracture
* Inadequate debridement
* Gross contamination
* Farm related or freshwater immersion injuries
* Delay in treatment \>12 hours
* Delay in antibiotic administration
102
Describe Brooker Classification
Classification for HO
class I: represents islands of bone w/in soft tissues about hip
class II: inclues bone spurs in pelvis or proximal end of femur leaving at least 1 cm between the opposing bone surfaces;
class III: represents bone spurs that extend from pelvis or the proximal end of femur, which reduce the space between the opposing bone surfaces to less than 1 cm;
class IV: indicates radiographic ankylosis of the hip;
103
Classic radiographic findings with TB arthorpathy?
Phemister's triad
juxta-articular osteopaenia/osteoporosis
peripheral osseous erosions
gradual narrowing of joint space
\*Major dDx of inflammatory arthritis - always ask
104
What gives the greatest risk for multiple joint sepsis?
RA
105
Risks of Intimate Partner Violence
Younger age
Shorter duration of
relationship
coexistence of emotional, psychological or
sexual abuse
drug or EtOH dependency
106
CRF in orthopaedic surgery:
Its bad - they have 2x increase in risk of complications including mortality
107
Stress Strain curve: elastic zone
zone where a material will return to its origina shape for a given amount of stress
108
4 principles of antibiotic stewardship
1. determining appropriate indications ofr antibiotic administration
2. choosing correct Abx based on known or expected pathogen
3. determining the correct dosage
4. determining the appropriate duration of treatment
109
Gram positive cocci in chains
What do you think of?
Nec fasc
Is strep pyogenes
vs. gram + in clusters: staph
110
3 phases of distraction osteogenesis
**(1)** Latency phase (5-7 days) (after corticotomy)
**(2)** Distraction phase (1 mm per day [approximately 1 inch per month])
**(3)** Consolidation phase (typically twice as long as the distraction phase)
111
What fluid should you resuscitate with in SIADH?
Normal saline
It keeps intravascular sodium high (counteracting dilutional effect of SIADH)
112
Classifications of Non-union: Name 2
Type:
* atrophic
* oligotrophic
* hypertrophic
Location
* intraarticular
* metaphyseal
* diaphyseal
113
What is the only calcium disease with decreased ALP?
Hypophosphatasia
b/c it's a disease of ALP with a mutation in Tissue nonspecific isoenzyme of ALP (TNSALP)
114
nerve grafts should be _______ (longer/shorter) than the defect
10-20% longer
as it will shorten with fibrosis
115
Define the value of an intervention
the quality of the intervention divided by the cost of the intervention, measured over an adequate time horizon
JAAOS 2013
116
The Frostbite complication of vasospastic disease: what can you use to treat it (2)
Calcium channel blockers
surgical sympathetectomy
117
What populations are considered vulnerable and require consent from IRBs prior to enlisting in clinical trials?
Fetuses
Children
Pregnant women
prisoners
118
4 ways to reduce risk of fat emboli syndrome
Early fixation of long bone fracture
Overreaming the femoral canal during TKA
Use of reamers with decreased shaft width reduces the risk during femoral reaming for IM fixation
Use of Ex-Fix as definitive long bone fractures in the medially unstable patients
119
What antibiotic never to give to a kid?
FLuoroquinolone
120
What is the max acute shortening of a bone you can do?
3-5cm (almost same as lengthening)
due to kinking of NV bundles
121
Define the Endurance limit
maximal stress under which an object is immune to fatigue failure regardless of the number of cycles
122
Cardinal signs of CRPS
Exaggerated pain
swelling
stiffness
Skin discoloration
Also:
vasomotor disturbances
trophic skin changes
hyperhidrosis
flamingo gait (if knee involved)
123
FHB or FDB flaps can be used to cover:
Small heel defects
124
Ortho cases that have increased risk of PE
Hip fracture
Elective hip arthroplasty
* Intra-operative PE occurs more frequently with cement pressurization of the femoral canal
Elective knee arthroplasty
Spine fracture with paralysis
\*EARLY DETECTION & TREATMENT MOST IMPORTANT FOR SURVIVAL
125
Name the values of medical ethics
Autonomy: patient has right to refuse or choose treatment
Non-maleficence: primum non nocere
Beneficence: maximize benefit and minimize risk (for individual & society)
Justice: distribution of health resources (fairness & equality)
Dignity & respect: the patient (and person treating patient) has right to dignity
Truthfulness & honesty: informed consent (Tuskegee Syphilis study)
126
Stress Strain curve: yield point
transition point between elastic and plastic deformation
127
Name values that commonly apply to medical ethics (not just the pillars)
Autonomy
Non-maleficence
Justice
Beneficence
Dignity: the patient has the right to dignity
Truthfulness & honesty: concept of informed consent. Relates back to Tuskegee syphylis strudy
128
What do you use to compare 3 or more continuous variables?
ANOVA
129
Name 4 ways to prevent transmission of HIV (PPE etc)
* Double gloving
* Instrumented suture tying
* Waterproof gowns
* Passing instruments between surgeon and nerve through an intermediate tray
130
Crevice corrosion
occurs in fatigue cracks due to differences in oxygen tension
131
Ortho procedures/injuries with high rates of DVT: (5)
Spine fractures with paralysis
Elective TKA
* 2-3x greater rate of DVT than THA
Elective THA
Hip fracture
Polytrauma
\*RATES OF DVT DO NOT CORRELATE WITH PE OR DEATH AFTER THA/TKA
132
Outcomes of orthopaedic surgery in a patient who uses opoioids pre-op
Poorer overall
More complications
More painful recoveries
133
Most common source of infection in freshwater?
Skin flora:
Staph
Strep
134
Describe 4 elements of medical negligene
_Duty:_
duty of the physician is to provide care equal to the same standard of care ordinarily executed by surgeons in the same medical specialty
_Breach of Duty:_
The actions, or failure to act, deviates from standard of care
_Causation_
Breach of duty was the direct cause of the patient's injuries
_Damages_
Monies awarded as compensation for injuries sustained as the result of medical negligence
135
Only RA drug shown to increase risk of infection post op?
Etanercept
no evidence for any of the others
136
Role of Satellite Cells?
Muscle injury repair
137
Characteristics of an intimate partner violence abuser
Refuses to leave patient alone
Overly attentive
Aggressive or hostile
Refuses to let patient answer their own questions
138
What do you use to compare 2 or more categorical variables?
Chi square test
139
Risks for paralytic ileus in ortho
Type of surgery
spine surgery
lower extremity reconstruction
trauma ± abdom injuries
140
Finite element analysis
breaking up a complex shape into triangular or quadrilateral forms and balancing forces and moments of each for to match it with its neighbour
141
Signs of sacral dysmorphism
_Assessed on outlet view_
Mamillary bodies
Lumbarization of S1
Sacraliation of L5
Oblong foramen
Preservation of sacral disc spaces
Tongue in groove sign
142
For optimal wound healing, ABI should be:
\>0.45
vs. ischaemic index \>0.5
143
Classification & Treatment of Ex-Fix infections
144
Conditions that promote bone formation in distraction osteogenesis
**a.** Low-energy corticotomy/osteotomy
**b.** Minimal soft tissue stripping at the corticotomy site (preserves blood supply)
**c.** Stable external fixation to eliminate torsion, shear, and bending moments
**d.** Latency period (no lengthening) of 5-7 days
**e.** Distraction at 0.25 mm 3-4 times per day (0.75-1.0 mm per day)
**f.** Neutral fixation interval (no distraction) during consolidation
**g.** Normal physiologic use of the extremity, including weight bearing.
145
Hooke's law
when a material is loaded in the elastic zone, the stress is proportional to the strain
146
What is a viscoelastic material?
one that exhibits a stress-strain relationship that is dependnet on the load AND the *rate* at which the load is applied
ie:
ligaments, bone
147
Definition of osteoporosis?
T-score more than 2.5 standard deviations below that of a 25 year old individual
(T score
148
Load relaxation
Load relaxation is characterized by decreased peak loads over time with the same amount of elongation
Gets stretched out and gets weaker
Occurs after releasing the mobile wad (just kidding)
149
Creep
Chris dowding
Increased load deformation with time under a constant load
150
What are the criteria for causality in research?
_Bradford Hill Criteria_
* Strength (effect size)
* consistency (reproducibility)
* Specificity
* Temporality
* Biological gradient
* Plausibility
* Coherence
* Experiment
* Analogy
* ?Reversibility?
Sex Causes Size To Be a Plausibly Crafted Excuse, Always
151
What are new 4th generation composite sawbones made out of?
How do they compare to the real things?
fibreglass resin and epoxy
They replicate physiologic or near physiologic values for torsional, axial compressive, and lateral bending stiffness, as well as cancellous screw pullout strength
They are also cheaper than cadavers
One downdie is that they don't have soft tissue overlying it
152
Define anisotropic material
one that possesses different mechanical properties depending on which way it is loaded
ie: bone, ligaments
153
True or false:
You are mandated to report intimate partner violence to police/authorities
False
Only report with the patient's permission
154
Most common electrolyte abnormality after ortho surgery in patient with CRF
hyperkalemia
155
What imaging to order for HO?
Regular x-rays ± CT
Bone scan has NO ROLE
156
Stress Strain curve: breaking point
point where an object fails and breaks
157
6 good prognostic indicators in nerve injury
Young
Early repair
Single function nerve
Distal location (level)
Sharp transection
Short nerve graft
158
For optimal wound healing, transcutaneous oxygen tension should be:
at least 30mmHg
Preferably 45mmHg
159
Open fracture with fresh water contamination. Treatment?
fluoroquinolone (cipro, levofloxacin) or a third- or fourth-generation cephalosporin (eg, ceftazidime).
160
CRPS around knee - most common xray finding?
Patellar osteopenia
161
Difference between dwarf & midget
Dwarf: disproportionate short stature
Midget: proportionate short stature
162
What is PTH's effect on calcium and phosphate?
Calcium: increases it (increase blood levels)
Phosphate: decrease blood levels
PTH = phosphate trashing hormone
163
When does peak blood flow occur in fracture healing?
at 2 weeks
normal by 3-5 months
most important determinant of fracture healing
164
Signs of Tension pneumothorax
How do you treat
Deviated trachea (away from side)
hypotension
JVP
Hyper-resonant
Treatment:
Needle decompression
2nd intercostal space, midclavicular line
Followed by chest tube
4th/5th intercostal space, anterior axillary line
165
Fretting corrosion
Occurs at contact sites between 2 materials that are subject to micromotion
166
In RA Foot, what is the main risk factor for developing post-op infection?
Previous infection
| (NOT the continuation of DMARDs)
167
Strain
relative measure of deformation of an object
=change in length / original length
168
Abnormal findings in NCV
Increased latencies
Decreased conduction velocity
Decreased amplitude
Prolonged/absent evoked response
169
Define Disability
Limitation of an individual’s capacity to meet certain personal, social, or occupational demands.
This is not an objective medical designation, but a legal definition.
vs. Impairment: loss of function from a physical or anatomical derangement
170
Define fatigue failure
failure at a point below the ultimate tensile strength secondary to repetitive loading
it depends on the magnitude of stress and the number of cycles
171
Stress Strain curve: plastic zone
zone where a material will not return to its origina shape for a given amount of stress
172
Why isn't free fibular graft used anymore?
High rate of complications and donor side morbidity
Higher risk of fracture
BUT it gets 95% union rate
JAAOS
173
For optimal wound healing, total lymphocyte count should be:
\>1500/mm^3
174
What is the toe region of Stress Strain curve?
applies to a ligament's stress/strain curve
represents straightening of the crimped ligament fibrils
175
Steroid management perioperatively
If \<5mg/d of prednisone or equivalent, NO perioperative dosing required
If \>5mg/d prednisone:
_Mild surgery:_ give Hydrocortisone 25mg (5mg predinisone)
* ie knee arthroscopy, carpal tunnel
_Moderate surgery:_ Give 50-75mg hydrocortisone (10-15mg prednisone)
* joint arthroplasty
_Major surgery:_ 100-150mg hydrocortisone (20-30mg prednisone)
* polytrauma
176
Who may you need to consult in the management of segmental bone defects?
microvascular
plastic surgery
internal medicine
psychiatry
infectious disease
(as needed)
177
Definte T-score & Z-score as it pertains to osteoporosis
_T-score:_
BMD reliatve to a normal, young matched control (25yo F)
Used as a definition of osteopenia/porosis
osteopenia: T-score 1 - 2.5 STD below normal
osteoporosis: T-score \>2.5 STD below normal
_Z-score:_
BMD relative to similar aged patients
178
Initial management of frostbite
Rapid rewarming in 40-42C water for 30 minutes
avoid repetitive thaw-freeze cycles
179
Stress Strain curve: Young's Modulus
measure of stiffness (ability to resist deformation) of a material in the elastic zone
calculated by measuring the slope of the stress/strain curve in the elastic zone
higher modulus of elasticity = a stiffer material
180
What happens to muscles as you age?
Diameter AND *number of fibers* decrease
vs
disuse atrophy: diameter decreases but number of fibers stays the same
181
What is the most imporant factor in reducing fat emboli syndrome?
Early stabilization (within 24h) of long bone fracture
182
Presence of 6 variables below correspond to short life expectancy in orthopaedic oncology
Multiple spinal mets
Multiple extra-spinal mets
Unresectable lesions in major organs
SCI (complete or incomplete)
Aggressive CA: lung, osteosarcoma, pancreas
Critically ill
183
Salt water wound. You've given cipro. what else do you have to add in? Why?
Tetanus
Clostridium is in salt water
184
When should chronic renal failure patients have dialysis before elective surgery?
on the day of or the day before surgery
185
For optimal wound healing, toe pressure should be:
\>40mmHg
Will not heal if \<20mmHg
186
Chronic renal failure
Overall complication risk ?
Risk of fracture?
Complication risk 2x that of normal
almost 2x more likely to have fracture
187
Fat Emboli syndrome criteria
_1.1. Major: x 1_
* 1.1.1. Hypoxemia (PaO2 less than 60)
* 1.1.2. CNS depression
* 1.1.3. Petechial rash
* 1.1.4. Pulmonary infiltrates
_1.2. Minor: x 4_
* 1.2.1. Tachycardia
* 1.2.2. Pyrexia
* 1.2.3. Retinal emboli
* 1.2.4. Fat in urine
* 1.2.5. Fat in sputum
* 1.2.6. Thrombocytopenia
* 1.2.7. Decreased HCT
_1.3. Other_
* 1.3.1. PCO2\>55
* 1.3.2. pH
* 1.3.3. RR\>35
* 1.3.4. Dyspnea
* anxiety
188
What is the evidence for the regular prescription of abx for dental procedures in a patient with a TKA/THA?
Limited
Spiel - read if you want
They know that dental work (including regular brushing) increases bacteremia, and that antibiotics decreases that bacteremia. However, there has been no link of bacteremia to increased rates of PJI in post-op hip/knee patients
189
Preferred utility score for measuring quality in spine care?
QALY
quality adjusted life year
patient driven and can be used in economic evaluation, is easily communicable and can be compared across disease states
190
Outcomes of grouped/matched fascicular repair vs. epineurial repair
3 indications for grouped fascicular repair
indications:
median nerve in distal 1/3 forearm
ulnar nerve in distal 1/3 forearm
sciatic nerve
However, results are no better so maybe don't say this
191
Barriers to reporting intimate partner violence? (4)
Fear of retaliation
Shame
Difficulty reporting to male doctors
Fear of custody conflicts
Fear of loss of finances
192
Most important prognostic indicator in nerve injury
Age
Younger = better
193
AC current burns/electrocutions are associated with what non-ortho, life-threatening condition?
Ventricular arrythmias
194
3 factors associated with increased severeity of frostbite:
Alcohol consumption/intoxication
Contact of skin with metal or ice
Elevated wind chill factor
195
Although they understand that the evidence supporting it is limited, who do the AAOS and ADA suggest giving prophylatic antibiotics to for dental procedures?
What antibiotics are suggested?
TJA patients at increased risk of hematogenous seeding should be given prophylactic antibiotics prior to dental procedures, including:
* all patients for the first two years after TJA
* immunocompromised patients
* drug induced immunosuppression
* radiation induced immunosuppression
* inflammatory arthropathies including SLE and RA
_comorbidities including_
* previous prosthetic joint infection
* Type I (insulin-dependent) diabetes
* malnourishment
* hemophilia
* HIV
* malignancy
Suggest Cephalexin or clinda if allergic
196
When should a CRF on dialysis patient have a nephro consult preop?
Within a day before surgery
197
List 2 proinflammatory mediators
IL1
TNFa
These play a role in post traumatic OA after articular fracture
198
Risks of septic arthritis
Age \>80 years
Medial conditions (imunocompromised)
Diabetes
RA
Cirrhosis
HIV
History of crystal arthropathy
Endocarditis or recent bacteremia
IVDU
Recent joint surgery
199
5 contraindications to primary closure of an open fracture
* Inadequate debridement
* Gross contamination
* Farm related or freshwater immersion injuries
* Delay in treatment \>12 hours
* Delay in antibiotic administration
* Compromised host or tissue viability
200
7 ways to decrease radiation exposure
Reduced exposure time
increasing distance from beam
increased shielding (gown, thryoid collar, gloves, glasses)
Beam collimation
Using the low-dose option
Inverting the c-arm
Surgeon control of the c-arm
201
Mangled extremity severity score (MESS) takes into account what factors and predicts what?
Skeletal and soft tissue injury
Limb ischaemia
Shock
Age
Score \> 7 is highly predictive of amputation
Not saying you should amputate, just saying that it is an eventuality, so why not do it now
202
Management of Methotrexate perioperative
Continue
203
What are 3 questions to screen for IPV?
| (Sprague & Bhandari 2013)
Woman Abuse Screening Tool (WAST)
Have you been physically abused by an intimate partner?
Have you been emotionally abused by an intimate partner?
Have been sexually abused by an intimate partner?
204
Define Isotropic material
one that possesses the same mechanical properties in all directions
ie a golf ball
205
8 Ways to decrease blood loss
Tourniquet
Technique (cautery)
Cell saver
Controlled hypotension
Tranexamic acid
Gel foam
Surgicel
fibrin glue
local epinephrine
206
What are 2 disadvantages of tendons?
1 advantage?
(biomechanically)
Disadvantages
Demonstrates Creep & stress relaxation
Advantage
Strong in tension (more then bone)
Other characteristics:
viscoelastic with nonlinear elasticity
displays histeresis
207
How long do you hold cultures for TB? What are you culturing?
Hold at least 8-10 weeks
Culturing for mycobacteria
208
Side effect of quinolones (cipro)?
Toxic effect of chondrocytes leading to:
* ABnormal fracture healing
* increased risk of tendon rupture (achilles)
Do not give to kids
209
Therapies in treatment of paralytic ileus
minimization of opioids
early patient mobilization
pharmacologic intervention (prokinetics, anti-emetics)
multidiscipliary care
Chewing gum (intestinal motility via cephalic-vagal stimulation)
Use of regional anestheisa (prevention)
Surgery not indicated in absence of perforation or ischaemia
210
EMG abnormalities with denervation
_Abnormal insertional activity_
* Increased: denervation
* Decreased: muscle fibrosing
_Abnormal spontaneous activity_
* fibrillations
* fasciculations (indicate healing if at 3-6 months)
* Sharp waves
* complex repetitive discharges
* myokimic discharges
211
What type of bone loses mechanical strength with aging?
Trabecular \> cortical
212
What is a critical bone defect?
Void that will not fill without intervention
Subjective, but generally:
\>50% circumferential bone loss or length \>2cm
(jaaos 2015)
213
What factors will turn an open fracture into Gustillo 3 no matter the size of the wound?
Exposure to soil
Exposure to water (pools, lakes/streams)
Exposure to fecal material (barnyard)
Exposure to oral flora (bite)
Gross contamination on inspection
Delay in treatment \>12 hours
214
Kid steps on a nail
Initial management and abx?
Most common organism?
Abx for pseudomonas infection?
I&D in ER
No consensus on initial Abx - POSNA says you don't have to give any
Most common organisms: staph aureus
Most distinctive organisms: pseudomonas
Treat pseudomonas with certazidime (3rd gen ceph that is active vs. pseudomonas)
215
What happens clinically with an acute UMN lesion?
Initially:
* flaccid* paralysis
* decreased* tone
* decreases* reflexes
Not until hours - weeks that the classic signs of increase tone,reflexes etc will present
216
6 Risk factors for OM
Recent trauma or surgery
Immunocompromised
Illicit drug use
Poor vascular supply
Systemic conditions:
* DM
* Sickle cell
Peripheral neuropathy
217
What metal has a Young's Modulus most similar to cortical bone?
Titanium
218
Mechanism of Rituximab:
inhibits B-cells
it is a monoclonal antibody to CD20 antigen
219
In induced membrane technqiue, in second stage, what do you fill void with?
Autograft
Can have allograft but not more than 3:1 allo : autograft
220
Best candidate for a myoelectric prosthesis?
transradial amputation
221
Name 9 factors to decrease radiation from C-arm
Imaging small body parts (non-modifiable, but large parts have more radiation)
Position extreity further from x-ray source (closer = more rads)
use of mini c-arm
Maximizing distance between surgeon and beam
minimizing exposure time
Collimation
Orienting the beam in an inverted position relative to the patient
Avoid being in the path of the x-ray beam
use of protective shielding
222
List the components of informed consent
Nature of the problem
Proposed treatment to address the condition (if the surgeon has a specific recommendation)
Alternative treatments
Anticipated benefits of each treatment option
Risks and side effects of each treatment option
Consequences of no treatment
Assessment of the patient's understanding of the proposed treatment
(AAOS online)
223
3 independent predictors for foot ulceration:
absence of the Achilles' tendon reflex
a foot insensate to the 5.07 Semmes-Weinstein monofilament
a transcutaneous oxygen tension (TcPO2) of less than 30 mm Hg
224
Mechanism of Anakinra (Kineret)
recombinant IL-1 receptor antagonist
225
Name 7 resistance mechanisms of antibiotics
Beta lactamase
mecA mutational bacterial gene encoding an altered penicillin-binding protein.
Altered cell wall permeability
Creation of biofilm barrier
Active efflux pumps
msrA in staph
Ribosome alteration
226
What is a ductile material? Give an example
One that undergoes a large amount of plastic deformation
ie: metal
227
Order of nerve function return
"Some People Tend To Piss Me Off"
* Sympathetic
* Pain
* Temperature
* Touch (light touch)
* Proprioception
* Motor
Off (nothing - just finishes the mnemonic)
The 2 T's, TEmperature comes before TOuch
228
What is the risk of pin site infection in distraction osteogenesis?
80%
229
What kind of viruses do the following transmit after bites:
Humans
Rats/mice
Monkeys
Dogs, bats, skunks
Humans: HIV, Hep C, Hep B
Rats/mice: Hantavirus
Monkeys: Simian B
Dogs, bats, skunks: rabies (rhabdoviridae)
230
When can a worker's comp patient settle a claim?
When the patient is determined to reach maximum medical improvement when further restoration of function is no longer anticipated (as judged by the primary physician)
231
SIRS criteria
WBC: low or high
Temp: \<36 or \>38C
HR: above 90bpm
Resp: rate \>20 or PaCO2 \<32mmHg
232
Factors in decision to operate in HO?
Matured bone (corticated)
Bone scan has NO ROLE
233
Elastic deformation
reversible changes in shape to a material due to a load
material returns to original shape when load is removed
234
5 signs of LMN lesion
Weakness
atrophy
fasciculation
decreased reflexes decreased tone
235
Which direction is bone strongest & weakest in?
Strongest in compression
Weakest in shear
236
Stress Strain curve: ultimate (tensile) strength
defined as the load to failure
237
8 ways to decrease radiation exposure
* reduced exposure time
* increased distance from the beam
* increased shielding (gown, thyroid gland cover, gloves, and glasses)
* beam collimation
* using the low-dose option
* inverting the C-arm - source is far way so can include more in 1 picture
* surgeon control of the C-arm
238
You dropped bone on the floor but want to use it. What is the best way to sterilize it?
I&D with poviodine and allow it to dry
239
Antibiotic stewardship programs lead to a decrease in what type of infection?
C. diff
b/c C.diff comes from inappropriate abx killing gut flora
240
Induced membrane technique: when is second stage?
6-8 weeks later
241
Risk factors for abuse (11)
Pregnant: #1 risk factor:
* 40-60% of abused women were abused while pregnant
Female
Young age (19-29 years old)
Low-income families
Low socioeconomic status
Emotional abuse is a risk of physical abuse
Psychological abuse is a risk of physical abuse
Sexual abuse is a risk for physical abuse
Drug dependency
Alcohol dependency
\*History of Divorce is NOT a risk factor
242
T/F
Increased glucose is an independent risk factor for post-op infection even in the absence of dianosed diabetes
True
Increased glucose is just bad
(JAAOS 2014)
243
Name the WHO checklist steps and when they occur
Sign in: before induction
Time out: before skin incision
Sign out: before patient leaves OR
244
Distraction osteogenesis: what are times for total, latent, distraction and consolidation
Latent: ~10 days recommended
Distraction: determined by length of defect
Consolidation: 2x distrction
Total: 3x distraction
245
For optimal wound healing, Ischaemix index should be:
\>0.5
This is a measurement of doppler pressure at level being tested compared to brachial artery pressure
Basically an ABI for any part of the body
246
Eikenella Corrodens:
Gram staining & treatment
Gram negative
Treat with penicillin
247
How do the distraction and docking sites heal with disraction ostegenesis?
Distraction: intramembranous
Docking: endochondral
248
Components of WHO Time out
Before skin incision
249
Galvanic corrosion
dissimilar metals lead to electrochemical destruction
250
In a hospital with a high MRSA colonization rate, or in a patient with known MRSA colonization, what preoperative, prophylactic antibiotic do you use?
Vanco
"in a study performed at our institution, high-risk patients undergoing total hip or total knee arthroplasty or spine surgery were screened for MRSA and methicillin-sensitive S aureus (MSSA), and 3% were found to have nares colonized with MRSA. This pattern should alter local recommendations with regard to perioperative antibiotic prophylaxis in patients colonized with MRSA. Several studies have suggested that vancomycin be used for perioperative prophylaxis in patients at high risk of MRSA colonization and/or infection."
Although later they say there is no consensus but they advocate for vanco
(JAAOS 2014 - antibiotic stewardship)
251
What do you use to measure 2 independent continuous variables?
Student T-test
252
Define brittle material & give an example
Material that exhibits linear stress strain relationship up until the point of failure
Undergoes plastic deformation only with little to no plastic deformation
examples:
* Ceramic
* PMMA
253
PMMA:
What is the function of
* Benzoyl peroxide
* barium sulfate
* DMPT
* Hydroquinone
_Found in powder_
Benzoyl peroxide: initiator
barium sulfate: radio-opacifier
_Found in liquid_
DMPT: accelerator
Hydroquinone: stabilizer
The powder and liquid are mixed and a free radical polymerization occurs
254
How large of a bone defect can you use with:
Autograft
induced membrane technique
Free fibular graft
Distraction osteogenesis
Autograft: 5cm
Induced membrane: 10cm (JAAOS - prob more now)
Free fibular graft (10cm)
Distraction osteogenesis (unlimited)
255
When do you nerve graft?
What is the gold standard?
Defects \> 2.5cm
Autologous nerve graft
256
What man made material has a modulus of elasticity closest to cancellous bone?
Polyethylene
257
X-ray findings of AVN of femoral head post DDH treatment
1) Failure of appearance or growth of ossific nucleus at 1 year after reduction
2) Broadening of femoral neck
3) Increased density and fragmentation of ossified femoral head
4) Residual deformity of proximal femur after reduction
5) Shortening of the femoral neck
6) Greater trochanter overgrowth
7) Premature physeal closure
258
Features of CRPS
exaggerated pain (hyperesthesia, allodynia, hyperalgesia)
swelling
stiffness
skin discoloration
_Physical exam_
vasomotor disturbance
trophic skin changes
hyperhidrosis
"flamingo gait" if the knee is involved
_X-ray_
Osteopenia
259
List 6 causes of secondary osteoporosis (not aging/menopause)
_Lifestyle_
anorexia nervosa
excessive protein intake
smoking
EtOH
_Endorinopathies_
Hyperthyroidism
Hyperparthyroidism
Cushing's syndrome
DM
_Systemic disease_
Gaucher's
RA
AS
Psoriasis
_Oragn dysfunction_
CF
Asthma
COPD
Renal failure
Primary biliary cirrhosis
IBD
Celiac sprue
Organ transplatation
_Meds_
Steroids
Diuretics
Antiepileptics
MTX
Cyclsporin A
Excess thyroid hormone replacement
Aklylating chemotherapeutic agents
GnRH agonist
Cancer
