General Orthopaedics Flashcards
1
Q
Most likely metal to experience crevice corrosion?
A
316L Stainless steel
2
Q
Metal with highest risk of galvanic corrosion?
A
316L stainless steel and Co:Cr alloy
3
Q
How to reduce metal corrosion?
A
Use similar metals and plates
Passivation (coat metal)
Titanium alloy undergoes self-passivation
4
Q
Types of corrosion
A
1) Galvanic
2) Crevice
3) Pitting
4) Stress
5) Fretting
5
Q
Labs to get with thumb hypoplasia?
A
CBC (Fanconi anemia)
Chromosomal challenge test
6
Q
What is Parona’s space?
A
Potential space of communication between small finger and thumb - lies between fascia of PQ and FDP conjoined tendon sheaths.
7
Q
Types of Nerve injury?
A
Neuropraxia (Sunderland 1st) - focal demyelination (no fibrillation on EMG)
Anonotmesis (Sunderland 2nd degree) - conduction block and Wallerian degeneration. Endoneurium intact.
Neurotmesis - disruption of endoneurium.
8
Q
Latency and velocities seen in CTS?
A
Distal sensory latency > 3.2ms Motor latency > 4.3ms Velocity < 52m/sec Motor action potential decreases Sensory nerve action potential decreases
9
Q
How to differentiate TAR from radial clubhand?
A
TAR (AR) - thrombocytopenia and absent radius - typically has thumb present.
10
Q
Medial talar dome vs. lateral talar dome OCD lesions
A
Medial talar dome - more common, posterior, larger/deeper, no trauma.
Lateral talar dome - trauma, superficial, central or anterior, lower healing rates, more symptomatic.
11
Q
Pathophysiology of dupuytrens disease
A
Myofibroblast is dominant cell type - actin along long axis and extracellular fibronectin
Type III collagen predominates
12
Q
What is not invloved in Dypuytren’s disease?
A
Cleland’s ligament and transverse ligament
13
Q
Dexa Scan Measurements?
A
BMD: absolute scores from Lumbar spine and hip
T-Score: BMD relative to young women (30 yo)
Z-Score: BMD relative to similar aged patients
Osteopenia: L2-L4 density 1 - 2.5 SD below T-score
Osteoporosis: L2-4 density > 2.5 SD below T-score
14
Q
Biologics to to be used on osteoporosis?
A
Raloxifene - SERM (dont use if hx DVT)
Teriparatide (Forteo) - 1-34 amino terminal residues of parathyroid hormone, activates osteoblasts. Osteosarcoma risk in Pagets disease.
Denosumab (Prolia) - Ig2 against RANKL, don’t use longer than 2 years. Continuous infusion causes resorption.
15
Q
Mnemonic for bisphosphonates?
A
PRAZI-N and TEC-No
Pamidronate, Risedronate, Alendronate, Zolendronate, Ibanddronate - Nitrogen containing (inhibit farnesyl pyrophosphate synthase which is a mavelonate pathway to ultimately inhibit small GTPases)
Tiludronate, Etidronate, Clodronate - Non-nitrogen containing (Toxic ATP analog)
16
Q
Vitamin D and Calcium dosing recommendations?
A
1200-1500mg Calcium and 400-800 IU Vit D
17
Q
Pharmacologic agents in osteoporosis?
A
Calcium/Vitamin D Bisphosphonates (PRAZI-N and TEC-No) HRT Estrogen Replacement Calcitonin - reduce bone pain in osteoporotic fractures, binds to osteoclasts to inhibit Raloxifene (Evista) - SREM Teriparatide (Forteo) - 1-34 amino terminal of PTH Denosumab (Prolia) - anti RANK-L
18
Q
Types of Bone mineralization disorders
A
1) Vitamin D Resistant Rickets (Hypophosphatemic) - XLD
2) Vitamin D Deficiency Rickets (Nutritional)
3) Type I Vitamin D Dependent - AR
4) Type II Vitamin D Dependent - AR
5) Hypophosphatasia - AR
6) Renal Osteodystrophy High Turnover - Renal Dx
7) Renal Osteodystrophy Low Turnover - Renal Dx
8) Hyperparathyroidism - 90% adenoma
19
Q
Pathophysiology of Renal Osteodystrophy?
A
Low Ca, high phos, refractory high PTH, high alk Phos
Hypocalcemia - inability of kidney to convert vit D3 (25-OH Vit D3) to calcitriol by 1alpha-hydroxylase due to hyperphosphatemia. Results in insoluble CaPO4 to form and remove from circulation.
Hyperparathyroidism and Secondary Hyperphosphatemia - caused by hypocalcemia and lack of phosphate excretion.
Uremia related phosphate retention.
Complications - genu Valgum and B/L SCFE (Secondary spongiosa of metaphysis).
20
Q
Labs in metabolic bone disease?
A
Calcium Phosphorus Alk Phos PTH Vitamin D - 25(OH) Vitamin D 1,25(OH) Vitamin D
21
Q
Metabolic bone diseases with Elevated calcium?
A
Hypophosphatasia
Hyperparathyroidism
All others are low or low normal (Nutritional Rickets)
22
Q
Metabolic Bone diseases with elevated phosphate?
A
Hypophosphatasia
Renal Osteodystrophy
23
Q
Metabolic Bone diseases with decreased alkaline phosphatase?
A
Hypophosphatasia
All others elevated
24
Q
Metabolic Bone diseases with elevated PTH?
A
All with the exception of low turnover renal osteodystrophy Vit D resistant rickets Type II Vit D dependent Hypophosphatasia
25
Type 1 vs Type 2 Vitamin D dependent metabolic bone disease?
Type I has decreased 1,25(OH) Vit D - missing enzyme in proximal tubule of kidney (1-alpha-hydroxylase)
Type II has INCREASED 1,25(OH) Vit D - missing receptor for 1,25(OH) Vit D
26
High turn over renal bone disease vs. Low turnover renal bone disease
High turnover bone disease - secondary hyper PTH - Hyperphosphatemia lowers serum Ca, stimulates PTH results in bone resorption
Low turnover bone disease - No secondary hyper PTH
- Normal PTH levels - you get aluminum deposition into bone mineralization that impairs osteoblast proliferation and PTH release from PTH gland
27
Regulators of Ca and Phosphate metabolism
PTH - Chief cells of parathyroid glands
1,25(OH) Vitamin D - proximal tubule of kidney
Calcitonin - parafollicular cells of thyroid gland
28
Actions of parathyroid Hormone?
Decreased Ca levels cause release
Increased Ca and 1,25(OH) Vit D inhibit release
Results in increased Ca level and decreased Phosphate (phosphate thrashing hormone).
Kidney: Stimulates 1-alpha-hydroxylase to make active vitamin D, increase resorption of Ca, urinary excretion of Phosphorus
Bone: Direct cAMP mediated osteoclastic resorption of bone
Intestine: No direct effect, increased active Vitamin D results in increased absorption of Ca and P
29
Actions of 1,25(OH) Vitamin D
Stimulates intestinal resorption of Ca and P
Stimulates Osteoclastic resorption of bone
Results in increased Ca and P levels
30
Action of calcitonin?
From parafollicular cells of thyroid
Stimulated by elevated Ca levels
Inhibits osteoclastic resorption of bone (direct)
Results in decreased Ca levels
31
What is rickets?
Defect in mineralization of osteoid matrix due to inadequate calcium and phosphate
Prior to physeal closure called Rickets
After physeal closure called osteomalacia
32
Most common form of rickets?
Familial Hypophosphatemic Rickets (Vitamin D resistant Rickets)
- X Linked Dominant - PHEX gene
- inability of tubules to resorb phosphate, results in high phosphate in urine
- Low Phosphate and elevated alk phos. Normal PTH, Ca, Vitamin D.
- Triad of hypophosphatemia, short, lower limb deformities.
33
What zone of physis is widened in Rickets?
Hypertrophic zone
34
Nutritional vs. hypophosphatemic rickets?
Nutritional - low vitamin D levels is primary problem so there are low-norm Ca levels, low phos, high alk phos, and increased PTH levels - Tx vitamin D
Hypophosphatemic - XLD (PHEX gene) - low phosphate resorption and near normal Ca levels results in normal PTH levels, Tx with VitD and Phos
35
Mechanism of Factor V Leiden thrombophilia?
Altered Factor V cannot be inhibited by protein C. Thus Factor V (co-factor for Factor Xa) binds to Factor Xa to produce high amounts of thrombin and drive clotting.
36
Hypercoagulable disorders?
```
MTHFR/C677 gene (highest risk)
factor V Leiden
Antithrombin III deficiency
Protein C deficiency
Protein S deficiency
Activated protein C resistance
```
(M,3,5,C,S)
37
Brief overview of clotting cascade
```
Intrinsic Pathway - XII, XI, IX
Extrinsic pathway (endothelial damage) VII activated by TF (thromboplastin)
```
Factor X to Xa activates Factor II (prothrombin) to Factor IIa (thrombin) which activates factor I (Fibrinogen) to Factor Ia (fibrin)
38
Mechanism of Heparin?
Binds and activates antithrombin III to inhibit factors IIa, IIIm and Xa.
Subcutaneous version is unfractionated heparin.
39
What is fractionated heparin and mechanism of action?
Also known as low molecular weight heparin - enoxaparin (Lovenox) or Dalteparin
Several sites but main is inhibits Factor Xa.
40
Direct factor Xa inhibitors?
Rivaroxaban (Xarelto)
Apixaban (Eliquis)
Edoxaban (Savaysa)
Metabolized in Liver
41
Indirect Xa inhibitors?
Fondaparinux (Arixtra)
42
Coumadin mechanism?
```
Affects extrinsic clotting pathway and Vitamin K
dependent factors (II, VII, IX, X)
```
Inhibits vitamin K 2,3 epoxide reductase
43
Direct thrombin inhibitor?
Thrombin = Factor IIa
Dabigatran (Pradaxa) - Metabolized in kidney
Argatroban
44
Mechanism of TXA?
Antifibrinolytic that promotes and stabilizes clot formation
Competitively inhibits activation of plasminogen and binds lysine binding site. Plasmin breaks down fibrin.
45
Antiplatelet agents?
Aspirin (acetylsalicylic acid) - inhibits prostaglandins and thromboxanes (causes platelet aggregation).
Clopidogrel (Plavix) - binds ADP receptor on platelet to activate GPIIb/IIIa complex.
46
Mechanism of penicillins?
Bactericidal - blocks cross linking via competitive inhibition of the transpeptidase enzyme
47
Carbapenems
Imipenem
Meropenem
Doripenem
Ertapenem
Broadest activity - no MRSA or mycoplasma
48
Abx that bind 30S ribosomal subunit?
Aminoglycosides - Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin
Tetracyclines - Tetracycline, Doxycycline, Minocycline
49
Aminoglycosides and mechanism of action?
Gentamicin, Neomycin, Amikacin, Tobramycin, Streptomycin
Bactericidal - irreversible binding to 30S
Aerobic gram-negatives, enterobacter, pseudomonas
50
Tetracyclines and mechanism of action?
Tetracycline
Doxycycline
Minocycline
Bacterostatic - blocks tRNA
51
Abx that bind 50S subunit?
Macrolides (erythromycin, azithromycin, clarithromycin)
Chloramphenicol
Lincosamides (Clindamycin) - inbibits peptidyl transferase by interfering with amino acyl-tRNA complex
Linezolid
Streptogramins
52
Abx that interfere with DNA synthesis?
Fluoroquinolones - Ciprofloxacin, Norfloxacin, Levofloxacin
Metronidazole
53
Floroquinilones and mechanism of action?
Ciprofloxacin, Norfloxacin, Levofloxacin
4th generation: moxifloxacin, gemifloxacin
Inhibit DNA gyrase
Achilles tendon rupture, impaired fracture healing
54
Mechanism of rifampin?
Inhibits RNA transcription by inhibiting RNA polymerase (DNA dependent RNA polymerase)
55
Definition of sensitivity?
Probability that test results will be positive in patients with the disease
Detects disease! True positive.
A/(A+C)
Remember: set up 4x4 table with Test on left and Disease on top. A (upper left), B (upper right), C (lower left), D lower right.
56
Definition of specificity
Probability that test results will be negative in patients without the disease.
Detects Health!! True Negative.
D/(D+B)
Remember: set up 4x4 table with Test on left and Disease on top. A (upper left), B (upper right), C (lower left), D lower right.
57
Definition of positive predictive value?
Probability a patient with positive test will have the disease.
A/(A+B)
Remember: set up 4x4 table with Test on left and Disease on top. A (upper left), B (upper right), C (lower left), D lower right.
58
Definition of negative predictive value?
Probability a patient with a negative test will not have the disease.
D/(D+C)
Remember: set up 4x4 table with Test on left and Disease on top. A (upper left), B (upper right), C (lower left), D lower right.
59
Likelihood ratio?
Likelihood a given test result will be expected in a patient with the target disorder
Positive likelihood (Chances of a disease is changed by a positive rest) = Sensitivity /(1-Specificity)
Negative likelihood = (1-Sensitivity)/Specificity`
60
Relative Risk Definition.
Risk of developing disease for people with known exposure compared to risk of developing disease without exposure
= Incidence of exposure/incidence of no exposure.
- This is basically incidence (incidence in exposed/risk in unexposed). And a prospective cohort study design is the only type to calculate incidence.
61
Odds ratio definition?
Represents the odds that an outcome will occur given a particular exposure, compared to the odds that the outcome will occur without the exposure
= (axd)/bxc)
62
Where are odds ratios calculated from?
From case control studies (retrospective)
From logistic regression models
Odds ratios approximate RR when outcome is rare (<10%)
63
Number needed to treat definition?
Number of patients needed to treat to get favorable outcome.
NNT = 1/ARR
64
Type 1 vs Type 2 error
Type I Error: Reject null hypothesis even though true, alpha error set to 0.05
Type II Error: Accept null hypothesis even though false (Beta usually 0.2) Power = 1-Beta
65
What is a bonferroni correction?
Post-Hoc correction made to P values when several dependent or independent statistical tests are being performed simultaneously on a single data set.
66
Parametric data vs. non-parametric data?
Parametric: normally distributed
Non-parametric: Not normally distributed
67
Continuous data tests?
Parametric
- Two Groups (Paired) - Dependent (paired) t-test
- Two Groups (Unpaired) - Independent t-test
- Three or more - ANOVA
Non-parametric
- Two Groups (Paired) - Wilcoxon Rank-Sum Test
- Two Groups (Unpaired) - Mann-Whitney U Test
- Three or more - Kruskal-Wallis Test
68
Categorical Data Tests?
Parametric/Nonparametric
- Two or more variables: Chi Square
- Two or more variables (Small sample size): Fisher's exact test
69
What is a funnel plot used for?
Scatter plot of the intervention to detect bias in meta-analysis
70
Design of the ROC curve?
X-axis: False positive rate (1-specificity)
Y-axis: True positive rate (sensitivity)
Area under the curve - used to compare different tests, higher c-statistics mean better test.
71
Levels of Evidence?
Level 1: RCT, Meta-analysis
Level 2: Bad RCT (F/u <80%), Prospective cohort study, meta-analysis of level II
Level 3: Retrospective cohort study, case-control study, meta-analysis of level III
Level 4: Case series
Level 5: Case report, opinion, observation
72
What is a prospective cohort study?
Groups separated non-randomly into treatment groups and followed/compared. Exposure occurs after initiation of study.
Analysis reported as relative-risk
Level II evidence
73
What is a case control study?
Groups are separated by presence or absence of disease and examined for the prior exposure of interest.
Analysis reported as odds-ratio
Level III
74
Most common clinical study type in orthopaedics?
Level 4 (retrospective case series)
75
Hereditary neuropathies?
Friedreich Ataxia - AR disorder, cardiomyopathy and cavus foot, scoliosis
Charcot Marie Tooth - AD, myelin degeneration (PMP22 on Chr 17), Pes cavus from Tib ant and P brevis.
76
Anterior horn cell disorders
Spinal Muscular Atrophy (SMA) - AR with SMN gene lack of SMN-1 protein
Type 1 (Acute Werdnig Hoffman) - <6mo, no DTR, tongue fasciculations
Type II (Chronic WH) - 6-24 months may live to 40s
Type III (Kugelberg Welander) - 2-10 years, walk as children
Treat hip subluxation non-op
77
Causes of limb length discrepancies?
Congenital - PFFD, fibular deficiency, hemihypertrophy, DDH
Paralytic - CP, Polio
Infection, tumors, trauma
78
Angle in infantile blount disease?
Drennan metaphyseal-diaphyseal angle > 16 deg
79
Treatment of infantile blount disease?
If <3 years and stage I or II brace
Stage II and III proximal osteotomy
Higher stage need something crazy
80
Types of tibial bowing?
Posteromedial - probably mild, calcaneovalgus foot, will develop LLD (3-4cm)
Anteromedial - fibular hemimelia, equinovarus foot, assoc with coxa vara and PFFD, tarsal coalition and ball and socket ankle joint
Anterolateral - congenital pseudoarthrosis, NF, brace to prevent fx
81
Gene associated with clubfoot mutation?
PITX1 mutation
82
Deformity associated with club foot?
Cavus (tight intrinsics, FHL, FDL)
Adductus of forefoot (tight tibialis posterior)
Varus (tight tendoachilles, tibialis posterior, tibialis anterior)
Equinus (tight tendoachilles)
83
Most common types of tarsal coalitions?
Calcaneonavicular
Talocalcaneal
84
AIS MRI Indications?
```
Left thoracic curves
Pain
Apical Kyphosis
Rapid curve progression
Neurologic signs (abdominal reflexes)
Congenital anomalies
```
85
Factors affecting AIS progression?
Skeletal maturity - Risser sign, hand digit physes
Peak growth velocity - Prior to menarche, occurs prior to Risser 1, tri-radiate cartilage
Curve magnitude > 20 deg
Curve Type Thoracic>Lumbar and Double>Single
86
Scoliosis progression after maturity?
Thoracic > 50
Lumbar >30
1-2 deg per year
87
Treatment of AIS?
<25 deg and immature - observe
< 40 and mature - observe
25-40 deg and immature - brace
>50 - surgery
88
Measurement in early onset scoliosis?
RVAD - rib vertebral angle difference (Mheta)
> 20 has high risk for progression
RVAD = Concave - Convex
89
Congenital scoliosis with worst prognosis?
Unilateral bar with contralateral hemivertebrae
90
Measurement in congenital coxa vara?
Hilgenreiner-Physeal line - should be < 25 degrees
91
Classification for Legg-Calve-Perthes Disease?
Lateral pillar classification - only at the end of fragmentation phase.
A = none
B = <50% loss of height
B/C border - lateral pillar narrowed with height 50%
C = >50% loss of height
92
Prognosis in Legg-Calve-Perthes Disease
Worse if 6 and older and if total head involvement
Good outcome is good ROM and spherical head
93
Differentiation between multiple epiphyseal dysplasia and Spondyloepiphyseal dysplasia?
MED - autosomal dominant, COMP gene mutation, spine is normal, disproportionate dwarfism
SED - AD, Mutation on chromosome 12 (COL2A1), proportionate, spine involvement
94
Features and genetics of Diastrophic dysplasia?
Genetics - DTD gene (Chr 5), sulfate transporter protein results in undersulfation of proteoglycans, autosomal recessive
Features - short, cauliflower ears, hitch hikers thumb, fused PIPJs, severe club feet, kyphosis and scoliosis
Cervical kyphosis severe, quadriplegia a risk, urgent management required
95
Composition of bone?
40% Organic - Collagen (resistes tensile forces), proteoglycan (resists compressive forces), matrix protein
60% Non-organic - Hydroxyapatite (resists compression)
96
Composition of hydroxyapatite?
Ca10(PO4)6(OH)2
Resists compression!
97
Defect in Osteopetrosis?
Osteoclast malfunction - Carbonic anhydrase defect, OPG over expression, get decreased remodeling
Ruger jersey spine and erlenmyer femur
98
Pynknodysostosis
Cathepsin K deficiency
Casuses acro-osteolysis of terminal phalanges
99
Sclerosteosis
Sclerostin deficiency
Increased WNT/B-catenin and increased osteoblast activity.
100
Function of sclerostin and dickkoph-1 (Dkk-1)
Direct inhibitors of Wnt/B-catenin pathway (activates osteoblasts)
101
Chondroblast promoting conditions and growth factors?
hMSC in medium strain and low O2 conditions and in presence of SOX-9
Growth Factors (TIP) - TGF-B, IGF-1, PDGF
102
Function of chondrocytes?
Produce cartilage (collagen and PG)
From chondroblasts in the superficial/tangential layer
103
What gives cartilage compressive strength?
Composition of proteoglycan aggregate?
Proteoglycans (hydrophilic)
Keratin sulfate and chondroitin sulfate bind to protein core and chains are linked together on a hyaluronic acid backbone
104
Cartilage changes in osteoarthritis?
H2O increases while collagen and quantity decrease
Decreased x-linking and lower modulus
Chondrocyte number unchanged
Increased IL1, IL6, and TNFa. Collagenase/MMPs degrade collagen and stromelysin degrades PG
105
Cartilage changes in aging?
Old and stiff...
H2O decreases, collagen quantity unchanged
Stiffer collagen (increased x-linking and diameter)
Proteoglycan: increased keratin sulfate and decreased chondroitin sulfate.
Decreased chondrocytes
106
Intervertebral disc composition?
85% water, PG, collagen 1 and II
Nucleus pulposus
- high PG, low Col
- Type II collagen
- Compressive strength
Annulus Fibrosis
- Low PG and high Collagen
- Type I collagen
- Tensile strength
107
Changes seen in an aging disc?
Decreased H2O and decreased PG
108
Protein specific to ligaments?
Elastin
Also has type I collagen
109
What type of collagen dominates in ligament healing?
Type III Collagen
110
Changes in a healed ligament?
Increased number of fibers but lower x-linking, diameter, and mass
111
Protein that regulates tendon diameter?
Decorin
112
When are tendon repairs weakest?
During inflammatory phase (7-10 days)
113
In early OA what collagen type increases?
Type X
114
Diseases in reserve zone?
PKGD - matrix production
```
Pseudoachondroplasia (COMP gene)
Kneist syndrome (Col 2A1 gene)
Gaugher Disease (B-glucocerebrosidase)
Diastrophic dysplasia (AR, DTDST sulfate transport gene)
```
115
Diseases in the proliferative zone?
Cellular division
MEGA
MHE (AD, EXT 1, 2, 3)
Gigantism
Achondroplasia (AD, FGFR3)
116
Diseases in the Hypertrophic Zone?
Cellular hypertrophy - longitudinal growth
3 Ss
SCFE
SH Fx
Schmid
Nutritional rickets (ZPC)
Zone of provisional calcification involves Col X and is the last to calcify
117
Pathology of lead poisoning?
PTHrP regulates (inhibits) physeal maturation in the hypertrophic zone
Lead inhibits PTHrP and leads to accelerated maturation of bone at an earlier age (decreased peak BMD)
118
Diseases in the metaphysis of the growth plate?
Primary Spongiosa - woven bone - Corner Fx
Secondary spongiosa - lamellar bone - Endocrine SCFE and Renal osteodystrophy
119
Appositional growth of the growth plate?
Zone of Ranvier - fibrous ring from epiphysis to the diaphysis
Perichondral ring of Lacroix - contributes to physeal strength
120
Limb Embryology - Growth patterns
AER - proximal to distal (interdigital apoptosis) - FGF growth factor
ZPA - radial to ulnar - Shh gene
WNT - dorsal to ventral - Wnt (Wings on your dorsal surface)
121
Renal osteodystrophy knee deformity?
Genu valgum
122
Most common disorder of bone mineralization, genetics, mechanism, labs, treatment?
X-linked hypophosphatemic rickets (Vitamin D dependent), XLD - PHEX gene
Inability to resorb phosphate in the kidney
Low phos - everything else normal (Normal Ca, PTH, and Vitamin D)
Treat with phosphate and vitamin D
123
Hypercoaguable states?
```
M, 3, 5, C, S
MTHFR Gene
AT3 Deficiency
Factor V Leiden
Protein C and S deficiency
```
124
Osteoblasts derived from?
Mesenchymal stem cells
125
Transcription factors directing cells down osteoblast lineage?
RUNX2
126
Function of osteoblasts?
Form Bone
Regulate osteoclast activity
127
What causes a cell in the Osteoblast lineage to become an osteoblast?
Low strain, high O2 environment
```
BMP/SMAD (Ser-Thr)
Core binding factor a1 (Cbfa1)/RUNX-2
WNT/B-catenin
PDGF
IHH/IGF-2
```
128
Osteoblasts produce what?
```
Alkaline phosphatase
Osteocalcin
Type I collagen
Bone sialoprotein
RANKL
Osteoprotegrin (binds RANK to decrease activity)
```
129
Osteoblast activity is stimulated by what?
Intermittent PTH
130
Functions of Wnt proteins?
Promote osteoblast survival and proliferation
131
What can sequester Wnts?
Sclerostin (Scl) and dickkoph related protein 1 (dkk1)
132
Osteocytes are from what?
Former osteoblasts that are now enclosed in bone.
133
Receptors on osteoblasts
```
PTH - pulsatile = more bone, constant = resorption
1,25 Vit D
Glucocorticoids (decrease activity)
Prostaglandins (decrease activity)
Estrogen (increase activity)
```
134
Receptors on osteoclast?
Calcitonin - inhibits osteoclast function
135
Osteoclasts Make what in howships lacunae?
MMP
Cathepsin K
TRAP
136
How do osteoclasts bind to site for resorbtion?
aVB3 on osteoclasts bind vitronectin (on bone) via the RGD sequence (arginine-glycine-aspartate).
137
How do osteoblasts activate and downregulate osteoclasts
RANK-L production
Osteoprotegrin (OPG) - RANK receptor decoy and sequestors RANKL
138
What activates osteoclasts?
Inflammatory environment - IL-1, IL-6, TNF-a, PG-E2
VitD, PTH, PTHrP receptors on osteoblast cause increase in RANKL to activate osteoblast.
139
What inhibits osteoclasts?
Calcitonin (Direct inhibitor of osteoclasts), TGF-B, IL-10.
OPG and Estrogen (indirectly via OB/RANKL)
140
Function of osteocytes?
Detect strain and regulate bone
Produce sclerostin and communicate via canaliculi
141
How does sclerostin function?
Functions through the DKK-1 (dikkoph pathway) which decreases the WNT/B-catenin pathway to decrease osteoblast activity.
142
Defect in cleidocranial dysplasia
Autosomal dominant defect in CBFA-1/RUNx-2 results in defect in intramembranous ossification
Missing clavicles and teeth.
143
Types of collagen and defects?
Collagen I - BONEs, ligaments, tendons - OI
Col II - Cartilage - Dx SED and Kniest syndrome
Col III - tendon/ligament healing - Dypuytrens
Col V - stabilizes col I
Col IX - stabilizes Col II - MED
Col X - initial fx healing - Schmid chondrodysplasia
Col XI - stabilizes all types of collagen - Stickler syndrome
144
Proteoglycan composition and function?
Hydrophilic and give compressive strength
Keratin sulfate and chondroitin sulfate subunits bind on a protein core and are linked together on a hyaluronate backbone.
145
Articular cartilage collagen arrangement?
Superficial (tangential zone) - top 10-20% - has the highest Collagen II and H2O - collagen fibers arranged tangential to surface
Middle transitional zone
Deep Zone - highest PG with fibers arranged perpendicular to surface. Tidemark zone has Collagen X.
146
Key lubricating protein of synovial fluid?
Lubricin
147
Cells that make synovial fluid?
Type A cells - macrophage-like
Type B cells - fibroblast like and produce synovial fluid (ultrafiltrate of plasma).
148
Muscle fiber types?
Type 1 (slow twitch) - aerobic, high endurance, slow oxidative (first to be recruited)
Type 2A -
Type 2B - anaerobic, high speed, high strength, ATP-CP system
Force generated depends on orientation and cross sectional area of the muscle.
149
Muscle Changes with exercise?
Increased collagen turnover but increase in NET collagen
Anaerobic increases functional motor units and cross sectional area
Aerobic increased capillary density
150
Primary bone healing conditions
Low strain
No callus forms - intramembranous ossification and haversian/cutting cone remodeling.
151
Findings of hyperparathyroidism?
Increased PTH (Ademona)
```
High Ca
Low Phos
High AlkPhos (OB upregulation)
Brown tumors from focal demineralization
Complications from Hyper Ca - stones, groans, moans, osteporosis, pancreatitis.
```
152
Immune cell involved in metal allergy?
T cell mediated (Type IV)
153
Rheumatoid arthritis serology?
RF+ - IgM against IgG
HLA DR4+
Anti-CCPa (most sensitive/specific)
154
Cervical instability patterns in rheumatoid arthritis?
Atlanto-axial (ADI > 3.5mm flex/ex)
Basilar invagination (C2 cranial migration)
Subaxial subluxation
155
Hypersensitivity reaction type from lupus?
Type III hypersensitivity (immune complex damage)
156
Gout vs. pseudogout?
Gout - monosodium urate (Negative birefringence)
Pseudogout - calcium pyrophosphate dihydrate (Positive birefringence, blue rhomboids)
157
Antibiotics that target cell wall?
B lactams - penicillins, cephalosporins
Vancomycin
Bacitracin (permeability)
158
Antibiotics that target protein translation?
Macrolids (Clinda, azithro) - 50S
Aminoglycosides (Gent/Tobra - 30S (vestibular tox)
Tetracyclines (Doxy) - 30S
Linezolid - 70S (Serotonin syndrome)
159
Which of the CC ligaments is stronger in the shoulder?
Conoid ligament stronger - more medial
Trapezoid more lateral
Acromial tip to CC ligament - 2.7cm
160
Types of acromion?
Bigliani classification
Type I - flat
Type II - curved
Type III - hooked
161
Types of os acromiale?
Most common type?
Pre-, Meso-, Meta-, Basi (From tip to origin)
Most common is junction between meso and meta
3-8% incidence
60% bilateral
162
Primary blood supply of the humeral head?
Posterior humeral circumflex
Secondary - anterior humeral circumflex (anterolateral ascending branch aka the anterior irrigating branch) but does supply the proximal humerus and is disrupted 80% of the time.
163
Divisions of the axillary artery?
Divided into 3 regions by the pec minor
Part I - Superior thoracic artery
Part II - Lateral thoracic trunk, Thoracoacromial trunk (ACDP)
Part III - anterior circumflex artery (terminates as the arcuate artery lateral to the intubercular groove), posterior humeral circumflex artery (supplies posterior greater tuberosity and head 64% of the time), subscapular artery (largest branch)
164
Most important for stability of the SC joint?
Posterior SC capsule - true for anterior translation and posterior translation.
165
Static stabilizers of the AC joint?
Capsule - superior/posterior capsule is most important for A-P stability
CC ligaments - Sup/inf translation
- Trapezoid 16.7mm from joint and provides posterior restraint
- Conoid - 35mm from joint provides superior restraint
166
Borders and contents of the quadrilateral space?
Teres minor (superior), Teres Major (inf), long head of the triceps (medial), humerus (lateral)
Contains - posterior branch of the axillary nerve and the posterior humeral circumflex artery.
167
Triangular Space vs. Triangular interval?
Triangular space - Teres minor, teres major and long head of the triceps (contains the scapular circumflex artery)
Triangular interval - teres major, long head of the triceps, humerus vs the lateral head of the triceps and contains the radial nerve and the profunda brachii artery.
168
Branches off the brachial plexus cords?
Lateral - Lateral pectoral nerve
Posterior
- Upper subscapular nerve, Thoracodorsal nerve, lower subscapular nerve
- Axillary and radial nerve
Medial
- Medial pectoral nerve
- Medial brachial cuteaneous
- Medial antebrachial cutaneous.
169
How calculate on vs. off track?
Off track if HS > GT
On track if HS < GT
GT = 0.83(D)-d
D = largest diameter of the inferior glenoid. d = bone loss)
170
Treatment of shoulder multidirectional instability
PT for at least 6 months.
Surgery is inferior capsular shift +/- closure of the rotator interval.
171
Pathology found in internal impingement in throwers?
PASTA lesion (articular sided tear)
Tight posterior capsule and anterior microinstability
Posteriorsuperior labral tear during late cocking.
Contact of the articular rotator cuff with the posterosuperior rim of the glenoid labrum. internali
172
Greatest tensile strength of the rotator cuff?
Bursal side (Greater tensile strength)
Articular sided - fails first.
Deceleration phase associated with tensile failure - posterior half of the supra and anterior half of the infra.
173
Indications for operative repair of partial rotator cuff tears
Articular sided tears
- >6mm
- > 50% thickness and tendon insertion
Bursal sided tears (more symptomatic and long healing time)
- >3mm
174
History in a SLAP tear?
Pain (100%), clicking, dead arm, instability, weakness, decreased throwing velocity
Vague shoulder complaints in young person
175
Types of SLAP tears and treatment
Snyder Classification
Type 1: degeneration and irregular surface
Type 2 - (MOST COMMON)
- Torn anterior to posterior
Type 3 - torn and detached from biceps (bucket handle tear)
Type 4 - Torn and propogated into the biceps tendon (<30% debridement, > 30% repair or tenodesis)
Types 1 and III - debride if anchor intact
Type 2 - repair vs. tenotomy/tenodesis
176
ASIA Score?
A complete
B sensation, no motor, sacral sparing
C - Incomplete - motor function preserved below neurologic level with 1/2 muscles grade <3
D - Incomplete - motor function preserved below neurologic level with 1/2 muscles grade >3
E - Normal
Defined as most distal level > 3/5 given them next rostral level is 5/5.
177
Brown Sequard sundrome
Hemitransection of cord
- Ipsilateral loss of motor and proprioception
- Contralateral pain and temperature loss
***Best prognosis
178
Spinal imaging during frcture?
Once a fracture is identified imaging of the entire spine is recommended - 4.6-10% of non-contiguous spinal injuries.
179
Radiographic diagnosis of occipitoatlantal instability?
Powers ratio BC/AO <1 (basion to posterior arch of C1)/(Anterior arch of C1 to opisthion)
Basion Dens interval <12
Orthosis treatment only if normal CT but positive MRI.
180
Risk of type II odontoid non-union?
```
Initial displacement > 5mm (most important predictor of non-union)
>6mm translation
>10 deg angulation
Age > 50
Posterior displacement
```
181
Hangmans fracture?
Bilateral pars fracture of C2
Type 1 - <3mm displacement, no angulation
Type II - >3mm traslation with significant angulation. Treatment is traction and halo
Type IIA - Significant angulation without translation. Tx extension and compression with halo. NO TRACTION.
Type III - translation, angulattion with uni or bilateral facet dislocation of C2-C3. High risk for neurologic injury.
182
TLICS Scoring
Based on morphology, neurologic involvement, posterior ligamentous complex.
Morphology - Compression (1), burst (2), translational/Rotation (3), distraction (4)
Neurologic - normal (0), incomplete (3), complete (2), cauda (3)
PLC - intact (0), indeterminate (2), injured (3)
Nonsurgical <3, indeterminate 4, surgery >5
183
AAOS recommendation for osteoporotic compression fractures
Strong - against vertebroplasty
Moderate - calcitonin for 4 weeks
Weak - bisphosphonate for prevention, L2 nerve block, kyphoplasty
Inconclusive - bed rest, herbal medicines, opioids, exercise, e-stim
184
Brace for compression fracture?
Prospective, randomized clinical trial, Kim et al 2012 in JBJS.
At 12 weeks no difference in pain, disability, radiographic appearance, patient satisfaction with brace, soft brace, rigid brace.
185
Components of the posterior spinal ligamentous complex?
Supraspinous ligament, interspinous ligament, ligamentum flavum, facet joint capsules.
186
How is lauge-hansen classificaion used?
First is foot position and then second is force vector - example supination external rotation.
187
Blood supply to the talus?
Artery of the tarsal canal (body)
Tarsal sinus (head)
Deltoid artery (body)
Dorsalis pedis artery (head)
188
Talus fracture classification?
Hawkins
Type 1 - non displaced
Type II - fracture with subtalar dislocation
Type III - subtalar and ankle joint dislocation
Type IV - subtalar, ankle, and talar navicular joint dislocations.
189
Factors that affect osteonecrosis after talus fracture?
Comminution p < 0.03
Open fracture p < 0.05
190
What is the Hawkins sign and what does it predict?
Subchondral talar dome lucency - indicated presence of blood flow.
Best seen at 9 weeks
100% sensitivity (if you have it then no AVN), 57% specificity (if you dont have it then you still may not get AVN).
191
Types of subtalar dislocation and blocks to reduction?
Lateral (15%) - navicular lateral to the talus - PT or EDL
Medial (85%) - ST more mobile in inversion - Navicular is medial to the talus. EDB or TN capsule can block.
192
Blood supply to the femoral head?
Retinacular branches of the medial circumflex femoral.
193
Acceptable closed reduction of tibial shaft fractures?
<1cm shortening
Angulation < 5-7 degrees
Rotational deformity < 10 deg
Intact fibula (varus deformity > 5deg is likely) and comminution are relative contraindications to closed treatment.
194
Knee pain after tibial IMN?
10-60%
No difference with patellar tendon split vs parapatellar
Activity related and worse with kneeling
80% better with nail removal
195
Adult flatfoot deformity classification
Stage 1 - tenosynovitis, SLHR intact, normal radiographs
Stage 2A - flexible, planovalgus foot, tenosynovitis, SLHR normal, mild too many toes sign, TN undercoverage < 40 deg
Stage 2B - Flexible, + too many toes, TN undercoverage > 40 deg, loss or Mearys angle
Stage 3 - Fixed deformity with degenerative changes
Stage 4 - valgus angulation of the talus and ankle and degenerative changes at the ankle.
196
Treatment of PTTD
Stage 1 and 2 non-op
Stage 2B - FDL transfer, medial calc osteotomy, lateral column lengthening for TN undercoverage > 40%, possible cotton osteotomy (plantar flexion osteotomy of the medial cuneiform), +/- TAL
Stage 3 - triple fusion
Stage 4 - pantalar fusion
197
Most common forms of tarsal coalition?
Talonavicular (excise if >50%) and calcaneonavicular (excise)
CT to diagnose
MRI to assess if painful
198
Types of accessory navicular?
1 - sesamoid in PTT
2 - Synchondrosis with navicular (most common symptomatic type)
3 - Fused accessory
199
When to do x-rays with bow legs?
```
Persistent varus at 2 years
Varus > 20 deg at any age
Short (<10th percentile)
Lateral thrust
Unusual diet
Family hx
```
200
Assessment of xrays in bowed legs?
Tibio femoral angle
Mechanical axis
Metaphyseal-diaphyseal angle
201
Langenskiold classification and the MD angle
Infantile blounts disease classification
1-2 - irregular metaphyseal ossification
3 - definite physeal deformity, fragmentation
4 - early bar formation
5 - profound physeal disruption
6 - severe articular disruption
Metaphyseal diaphyseal angle (Drennans) - <10 deg 95% physiologic. >16 deg 95% Blounts.
202
Blounts disease non-operative treatment
Age < 2.5 and Langenskiold 1-2
Risk factors for non-op failure
- Weight > 90%
- Varus thrust
- Age >3 years at brace initiation
- Bilateral
- Langenskiold III or higher
203
Operative treatment of Blounts disease
Age >3, Langenskiold stage II-III, perform before age 4 to decrease risk of deformity and bar formation
Proximal tib-fib osteotomy and over-correct into 5-10 degrees of valgus, can also use guided growth.
Late onset - may need to correct multiple deformities (tibial varus, femoral varus, internal tibial torsion, increased posterior slope, LLD).
204
LLD treatment guidelines
0-2cm - no tx
2-5cm - shoe lift, epiphysiodesis, shortening, lengthening
5-15cm - lengthening
>20cm - prosthetic fitting, amp.
205
Association with hemi-hypertrophy?
Beckwith-Wiedemann syndrome
- omphacele, neonatal hypoglycemia, macroglossia, embronyal tumors (Wilms tumor)
- Sporadic vs AD vs chromosome 11
- Get renal/abdominal ultrasound every 6 months until age 8 to screen for tumor or hepatoblastoma.
206
Tibial deficiency treatment
Depends on quadriceps mechanism and presence of proximal tibia.
Amp if neither
Fibular centralization - need quad 3/5 and age <1 year, no fibular bowing.
207
Focal femoral deficiency treatment?
Observation if bilateral
Lengthning - stable hip with femoral head, foot works, <20cm femur and >50% contralateral
Knee arthrodesis, syme amp - foot above knee level
Femur-pelvic fusion - no femoral head
Rotationplasty - foot at knee level, good ankle motion, no femoral head
Amputation/knee disarticulation - femur <50% of contralateral
208
Types of tibial bowing
Anterolateral - think NF1 - prevent fractures with a clamshell brace. If fracture fix it.
Posteromedial bowing - probably mild. Associated with calcaneo valgus foot.
209
Congenital knee dislocation differential
Syndromic - Larsens, myelodyaplasia, arthrogryposis, ehlers danlos
Non-syndromic - sporadic, abnormal positioning.
210
Treatment of congenital knee dislocation?
Casting and splinting in flexion.
Pavlic for DDH
Surgery if <60 months flexion at 6 months - VY quads lengthening, release, k-wire/cast.
211
Paprosky acetabular bone loss classification
1 - minimal bone loss - cavitary defect, kohlers line intact
Type 2 defects < 3cm migration
2A - Superior migration
2B - superolateral rim loss
2C - Medial wall and tear drop loss, kohlers line is violated, consider medial wall graft
Type 3 Defects have >3cm migration
3A - UP and OUT. Extensive rim and column loss and ischial lysis. 30-60% bone loss
3B - Pelvic discontunity with ischial bone loss. Up and In defect. >60% bone loss. Consider cup cage, triflange, pelvic distraction, augments.
212
Paprosky femoral bone loss classification?
1 - minimal bone loss
2 - Extensive metaphyseal bone loss with intact diaphysis
3A - metaphyeal bone loss with 4cm diaphysis
3B - metaphyseal bone loss with less than 4cm bone diaphysis
4 - extensive metaphyseal bone loss and non-supportive diaphysis.
213
L4 - S1 nerve root exam
S1 - Foot eversion (peroneal tendons), plantar flexion, toe walking, achilles reflex, lateral foot
L5 - EHL, no reflex, dorsum of the foot.
L4 - Tib ant, patellar tendon reflex, Medial foot border, quad
214
C5 - T1 nerve root exam
C5 - biceps, deltoid, lateral arm, biceps reflex
C6 - wrist extension, lateral forearm, brachioradialis reflex
C7 - Triceps, wrist flexors, finger extension, triceps reflex, sensation to posterior arm and middle finger.
C8 - Interossi, finger flexors, no reflex, lateral forearm and hand sensation
T1 - Interossi, no reflex, medial arm sensation.
215
Roots for iliohypogastric, ilioinguinal, LFCN, genitofemoral nerve, femoral nerve, obturator nerve, sciatic nerve.
Iliohypogastric and ilioinguinal - L1
Genitofemoral nerve - L1-2
LFCN - L2-3
Femoral nerve - L2, L3, L4
Obturator nerve - L2, L3, L4
Sciatic nerve - L4 to S2/3
216
Vertebral artery anatomy?
Enters trasnverse foramen at C6 95% of time. Next most common is C5 followed by C7 then C4.
217
Southwick neck landmarks?
```
Hardpalate - arch of the atlas
Hyoid bone - C3
Thyroid cartilage C4-5
Cricoid cartilage - C6
Carotid tubercle - C6
```
218
Pneumonic for metastatic spine treatment considerations?
```
NOMS
Neurologic status
Oncological diagnosis
Mechanical stability
Systemic disease
```
219
Cervical spine in down syndrome?
C1-2 instability in 15-25% screen by 5 years
ADI > 4.5mm - avoid stress across head/neck
ADI 10mm or neuro sx - stabilize
220
Diastrophic dysplasia overview
```
AR - Sulfate transporter gene
Rigid clubfeet - need release in 50%
Cervical kyphosis
Scoliosis
Hitchikers thumb and califlower ears
```
221
Diseases associated with Type II collagen mutations?
SED congenita
SED Tarda - late onset can be x-linked or AD
Kniest Dysplasia - AD, COL2A1
Stickler syndrome - AD, eye stuff,
222
Sites of compression of the radial nerve?
FREAS
Fibrous bands (anterior to radial head)
Recurrent radial vessels (leash of henry) - cross PIN to supply mobile wad
ECRB
Arcade of Frohse (fibrous proximal supinator, most common)
Supinator (distal)
223
Medial knee anatomy (layers)
Layer 1: Sartorius and fascia
- gracilis, semiT and saphenous nerve
Layer 2: Semimem, superficial MCL, MPFL, POL
Layer 3: Deep MCL, capsule, coronary ligaments
224
Where does MCL and MPFL originate on the femur in relation to the ME, AT, GT
MCL is proximal and posterior to the medial epicondyle
MPFL is Anterior to the GT and anterior and distal to the AT.
225
Lateral knee structures (layers)
Layer 1: ITB, Biceps femoris
Common peroneal nerve
Layer 2: Patellar retinaculum
Layer 3
Superficial - LCL, fabellofibular ligament, ALL
- Lateral geniculate between superficial and deep
Deep - Acruate ligament, coronary ligament, popliteus tendon, popfib ligament, capsule
226
Types of meniscus tears?
```
Radial
Oblique
Flap or parrot beak
Vertical/longitudinal
Bucket handle
Complex/degen
```
227
Pediatric both bones treatment guidelines?
Plastic deformation - reduce if greater than 20 degrees angulation, 4 yo
Under 8 yo - 15-20 acceptable
Over 10 yo - 10 deg midshaft, 15 deg at distal 1/3
- Bayonet opposition acceptable in children under 10 years of age with 1cm shortening.
10 degree residual angulation = 20 deg loss of rotation.
228
Study used to calculate incidence?
Prospective cohort study
229
Bias vs. confounding?
Bias - systematic errors in methodology
Confounding - unaccounted variables that can explain associations
230
How to examine bias in results of a meta-analysis?
Funnel plot
231
Incidence vs. prevalence?
Incidence (inflow) - new cases per time period. Eg 10 per 1000 per year
Prevalence (Pool) - proportion of existing cases within a population
232
Relative risk vs. odds ratio?
RR - ratio of incidence between two groups
OR - ratio of probabilities of an outcome between two groups
233
How to interpret RR and OR?
RR - risk in exposed/risk in unexposed.
RR > 1 means risk greater than if not exposed. Use a 95% confidence interval that cannot cross 1.
234
How is duchenne's MD transmitted?
XR
235
GMFCS levels predict what?
Long term motor function
Associated with increased rate of hip dislocation
236
Prognosis for young children with CP to walk?
Ability to sit independently by age 2.
237
Common type of test answer when looking to operate in CP question?
Spastic diplegia
238
What releases will worsen gait in CP
Achilles in crouch gait - dont do alone with hamstring contractures
Hamstrings are overlengthened possibe to get stiff knee or anterior pelvic tilt.
239
Common muscle transfers in CP?
Split Tib ant - dynamic supination in swing
Split tib posterior - hindfoot varus in stance
Rectus femoris for stiff knee (esp if stiff in swing)
Complete transfer of TA and TP are not recommended.
240
Mechanism of botulinum toxin?
irreversible pre-synaptic block of release of Ach
241
Indications for dorsal rhizotomy?
Ambulatory spastic diplegia (GMFC 1/2)
242
Gene correlated with severity of disease in SMA?
Survival motor neuron II
SMA1 is the gene for SMN
243
Blood volume for children?
75 mL/kg
244
Diagnosis of compartment syndrome in children
3As
Anxiety, aggitation, increasing pain requirements
245
AVN after pediatric femoral neck fracture
```
Increases with displacement and decreases with delbet type
I: 50-95%
II: 25-50%
III: 15-30%
IV: 5-15%
```
246
Only strong recommendation from AAOS regarding femur fracture?
Children < 36 months be evaluated for child abuse
247
In tibial spine fractures what is most commonly entrapped in the fracture site?
Anterior horn of the medial meniscus.
248
Tolerances in pediatric tibial shaft fractures?
<1cm shortening, 5-10 deg angulation, 5 deg rotation
Risk of varus with intact fibula
Closed reduction, cast and weight bearing as tolerated.
249
Age and reason you see transitional ankle fractures?
12-15
Distal tibia growth plate closes central - posterior - medial - lateral
250
Surgical indications for pediatric distal tibia fractures
>10 degrees of angulation (SHI/II) or >2mm intra-articular displacement
- 50% growth arrest and greatest with medial mal (SH IV)
251
Pediatric NAT - most common fracture locations?
Humerus, tibia, femur
Skin lesions most common lesion
252
Diagnosis of child abuse?
40% sustain repeat abuse 5% death
```
Femur in non ambulator
Posterior rib fracture
distal humeral physeal
Metaphyseeal corner
Multiple fractures in different stages of healing
Patient age < 1 yo
```
253
Syndromes associated with syndactyly?
Polands - syndactyly, absent sternal pec major, hypoplasia
Aperts - FGFR2 - acrocephalosyndactyly
254
Most common type of pre-axial poly dactyly?
Type IV - duplicated proximal phalanx
Type II is number 2 - duplicated distal phalanx
255
Post axial polydactyly
AD inheritance
AA > caucasions
If caucasian - genetic evaluation is recommended
256
Types of Failure of differentiation?
Radioulnar synostosis
Syndactyly - simple vs complex (bone involvement) - 3rd webspace most common
Symphalangism
Camptodactyly - contracture (5th digit most common)
Clinodactyly - angulation in the radioulnar plane
Delta phalanx - physis not perpendicular to the long axis - excise bracket.
257
Treatment of pre-axial polydactyly?
Associated anomalies are rare
Preserve bifurcated EPL/FPL and thenars
Collateral ligament reconstruction (radial collateral ligament)
258
Acceptable pediatric proximal humerus fracture parameters
<5: 100% displacement, 70 deg angulation
5-12: 50-100% displacement, 40-70 deg angulation
>12yo: <50% displacement, <40 deg angulation
Closed reduction: 90 abd, 90 ER
Open fx = open reduction
Interposed - biceps, periosteum, muscle gets open reduction
259
Pediatric lateral condyle fracture parameters and complication
<2mm - cast/observe
2-4mm, hinged - CRPP +/- arthrogram
>2mm, malrotated - ORIF
Make sure to get an internal oblique XR
Complications - cubitus valgus, tardy ulnar nerve palsy, lateral spur (periosteal displacement)
Lateral approach must preserve posterior blood supply
260
Treatment of radial neck fracture in peds?
Rule of 3s - <30 angulation, <3mm translation, 1/3 of radial head
If > 60 deg angulation try percutaneous reduction
261
Pediatric forearm fractures - acceptable parameters?
< 8yo: 20 midshaft angulation, bayonet apposition, no rotation
>8yo: 10 midshaft angulation, no rotation
Plastic Deformation
<4 yo: angulation <20 deg will remodel
>4yo: reduce anything greater than 20 deg.
262
Cause of dorsal bunion in pediatric clubfoot?
Tx?
Dorsiflexed first MT and plantar flexed great toe
- Weak achilles and PL from lengthening or release
Overpowered by strong FHL and TA
Tx: MTP plantar release, FHL transfer to MT neck, +/- plantar flexion osteotomy at bast of 1st MT.
263
Deformity and XR of congenital vertical talus?
Ankle equinus with midfoot dorsiflexion, hindfoot eversion and forefoot abduction
Dorsal dislocation of navicular on talus
50% due to genetic or NM causes.
XR - lateral view in plantar flexion - axis of 1stMT above talus (navicular does not ossify until 3 years, infer position with 1st met) - rules out oblique talus which reduces with plantar flexion
Lateral view in dorsiflexion - no correction of vertical talus
264
What condition do you need to rule out with metatarsus adductus?
Skew foot - adducted forefoot with hindfoot valgus and lateral navicular subluxation with a plantarflexed talus.
265
Benign pediatric foot conditions
1) Metatarsus adductus - 85% resolve
Calcaneovalgus foot - extreme dorsiflexion - A/w PM tibial bowing, L5 spina bifida, observe and stretch
2) Flexible flatfoot - normal until age 5, if asymptomatic in adolescents observe, stretching/arch support if painful. RARE for surgery - calcaneal neck lengthening or 3C osteotomy.
3) Osteochondroses - Severs (calcaneal apophysitis), Iselin disease (5th metatarsal apophysitis).
4) Kohlers disease - navicular AVN - SLC can decrease symptom duration, no bx, no MRI.
266
Pediatric osteotomies
Redirectional
1) Salter - single innominate
2) Steele - Tripple innominate
3) Ganz - Periacetabular
Recontouring - hinge on triradiate
1) Dega
2) Pemberton
3) San Diego
Salvage - rely on fibrous metaplasia
- Chiari
- Shelf
267
3 main types of rickets
1) Familial hypophosphatemic (vitamin D resistant) - due to impaired renal tubular phosphate absorption - XLD (PHEX gene). Treat with vit D and phosphate
2) Hypophosphatasia - AR due to defect in alkaline phophatase - Low alk phos and high urine phosphoethanolamine
3) Nutritional - genu varum treat with vitamin D
268
Pediatric conditions associated with C1-2 instability?
Mucopolysaccharidoses (including Morquio)
Pseudoachondroplasia
SED
Down syndrome
269
Injury Severity Score calculation?
Sum of square of 3 highest AIS scores (head/neck, face, thorax, abdomen, pelvis, extremities.
- Any score of 5 = 75
- ISS > 15 frequently used as definition of major trauma.
- Correlates with mortality, morbidity, length of stay
- Does not take into account bilateral injuries
270
How much blood can be lost before drop in BP?
30% (around 1500 cc)
Class 1 - 15%
Class 2 - 15-30%
Class 3 - 30-40%
Class 4 - >40%
271
Humeral shaft non-operative indications?
AP angulation < 20 deg
Varus/Valgus < 30 deg
< 3cm shortening
- Very distal shaft fractures may have acceptable results with bracing if low demand.
272
Imaging to see column of bone between AIIS and PSIS for supra acetabular pins?
Obturator outlet oblique
273
Acetabulum classification
Elementary
- PW, AW, PC, AC, Transverse
Associated
- T shaped, Transverse with PW, Posterior Column/Wall, ACPHT, ABC.
274
Tibial shaft non-operative parameters?
<2cm shortening
50% cortical apposition
Varus/valgus <5 deg
Flex/Ex < 10 deg
Intact fibula fisk for varus mal-alignment
275
BMPs used in tibia
BMP2 approved as adjuvant for open tibia
BMP7 for non-union
276
RUST Score
Tibial shaft fractures - breaks up into 4 areas (anterior, posterior, Medial, lateral)
Score per cortex (1-4)
1: absent callus, visible fx line
2: Callus present, visible fx line
3: Bridging callus, visible fx line
4: Remodeled cortex, invisible fx line (modified)
Standard 10 or modified 14 provide evidence of union.
277
FDA definition of non-union
No progression of healing on 3 sequential monthly x-rays
NO progression of healing over 4-6 months.
278
Most common intercarpal coalition?
Lunotriquetral
279
Intercarpal wrist ligaments
SL - Dorsal strongest, tear leads to DISI and SLAC
LT - Volar stronger, leades to VISI
280
Thumb CMC joint ligaments?
Primary is the Volar beak ligament
Dorsalradial ligament is second most important.
281
Vascular supply to the hand?
Radial and ulnar arteries - Ulnar dominant in 88%
Superficial arch from Ulnar and deep arch from radial artery.
282
Blood supply to the scaphoid?
Volar carpal branch and dorsal scaphoid branch both from the radial artery.
Volar carpal branch is the primary supply.
283
All sensory axons have cell bodies where?
Dorsal root ganglion
284
Intervals where median, ulnar, and radial nerves enter the forearm?
Median - Superficial and deep head of the pronator teres
Ulnar - superficial and deep head of the FCU
Radial - superficial and deep head of the supinator, found between brachialis and BR.
285
Nerve interconnections in the forearm?
Martin-Gruber 10-25%
Richie-Cannieu <10%
Both median to ulnar
Both motor
286
Anatomy of the lumbrical muscles?
4 total
From FDP tendon
Join interossei radially to form lateral band
Attach on dorsum of middle phalanx, distal phalanx
Flex MP, extend PIP/DIP
287
Anatomy of intrinsics?
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Interossei
PADS (palmar, adduction) - 3 (long finger cannot adduct)
DAB (dorsal, abduct) - 4
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From metacarpals join lumbricals to form lateral band.
Attach on dorsum middle phalanx, distal phalanx
Flex MP, extend DIP/PIP - all ulnar nerve
288
Thenar Muscles
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Abductor pollicis brevis
Opponens Pollicis
Flexor Pollicis Brevis - superficial and deep heads
- Thenar space palmar to Adductor
Adductor pollicis
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APB is most important for Abduction/opposition
APB, OP, Superficial head of FPB - medial nerve
Deep head FPB and Adductor - Ulnar nerve
289
Hypothenar muscles
Palmaris Brevis
Abductor DM
Flexor digiti minimi brevis
Opponens digiti minimi
All innervated by the ulnar nerve.
290
Most common anomalus intrinsic extensors?
Extensor digitorum brevis from dorsal radial carpal ligament
Can present as a mass on the dorsum of the hand.
291
Leddy classification?
Zone 1 flexor tendon injuries
1: to the palm must be fixed within 9 days
2: Retracts to A2 - 3 months - retraction prevented by vinculum longus
3: Retracts to A4 - retraction prevented by bone fragment - most common
292
Zone III extensor tendon injuries?
INjuries to the central slip
Loss of active extension and flexion posture
Closed treat closed - splint for 6 weeks, open treat with repair and I&D
Untreated injuries lead to a buotonniere deformity
293
Best prognosis for extensor tendon injuries?
Zone VI (Over MCPs)
294
Quadrigga vs. Lumbrical plus finger
Quadriga - inability to make full fist from incomplete excursion of noninvolved tendons
Lumbrical plus - extension during attempted flexion - treat with release of radial lateral band (lumbrical).
295
Dequervains tenosynovitis tendon involvement
First dorsal compartment - APL can have several slips and EPB can be in its own tendon sheath.
EPB is more dorsal
Injection works 50-80%
296
Intersection syndrome
ECRL/B as they intersect over APL/EPB
297
Tendon transfer for radial nerve palsy
PT to ECRB (not ECRL)
FCU to EDC (2-5)
PL to EPL
298
Most common congenital hand anomaly?
Syndactyly - 1:2000 live births
Complete, incomplete, simple, complex
Most common between long and ring fingers.
299
Most common polydactyly?
Post-axial - AD inheritance
300
Digit anomalies?
Camptodactyly - flexion deformity
Clinodactyly - lateral deviation
Kirners derofmity - volar curvature of distal phalanx
Symphalangism - failure of finger IP joint development
301
Blood supply to the thumb?
Princeps pollicis
Arises directly from the radial artery or the deep palmar arch
302
Kienbocks disease classification and treatment
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Lichtman
Restorative procedures
I: Norm XR, MRI positive with diffuse low T1 signal
II - XR with sclerosis, no collapse
IIIa: lunate collapse, normal alignment
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Salvage procedures
IIIb: lunate collapse, DISI
IV: Carpal DJD
Restorative: Joint leveling (Radial shortening if ulnar negative or capitate shortening if ulnar positive), revasc, radial metaphyseal decompression
Salvage: partial fusion, PRC
303
Muscles most affected in forearm compartment syndrome?
Deep - FPL, FDP, PQ
304
Most common cancer of hand and most common sarcoma of hand?
Cancer: Squamous cell
Sarcoma: Epitheloid sarcoma
305
Treatment indications for dupuytrens disease
MP joint contracture > 30 degrees
Any PIP joint contracture
306
What is not affected in dupuytrens disease?
Clelands ligament
| Transverse palmar ligament
307
Spiral cord formed from what and does what to NV bundle?
Pretendinous band, spiral band, lateral digital sheet, graysons ligament
Brings NV bundle superficial, proximal, and midline
308
Most important aspect for z-plasty?
All limbs of equal length
60deg increases length by 75%
309
Cross finger flap vs. reverse cross finger flap
CFF: tissue from dorsum of a finger to palmar surface of an adjacent finger
- large palmar oblique
rCFF: palmar skin to cover dorsal wound
310
Innervated local hand flaps?
VY - transverse or dorsal oblique finger tip amps, can preserve sensation in musicians
Moberg advancement: Thumb only can advance up to 1.5 cm
Neurovascular island flap: severe thumb pulp defects - usually ulnar side of ring or middle finger.
- Best axial flap for digital amputations
311
Best hand flap for defects on the dorsum of the fingers, thumb?
Dorsal metacarpal artery flap - volar dorsal perforator found at the metacarpal head - raised on a proximal antegrade or reverse flow
If dorsal proximal phalanx - axial flag flap
312
Common chemical burns and treatments?
Hydrofluoric acid (industrial cleaning) - Ca Gluconate
Elemental sodium (meth) - mineral oil not water because it will explode
White phosphorus (fireworks) - copper sulfate to identify particles and submerge in water
313
Digit replant indications?
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Thumb
Multiple fingers
Single finger distal to FDS
Hand, wrist, arm
Child
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Order of repair - BEFANV
Bone, Extensor tendon, flexor tendon, artery, nerve, vein
If multiple digits do structure by structure
314
What gives nerves tensile strength and elasticisy?
Epineurium
315
Median nerve laceration commonly occurs with injury to what tendon?
FCR
316
CRPS 1 vs 2
Type 2 has an identifiable nerve injury
317
Strength/sensory return after carpal tunnel release?
Pinch strength by 6 weeks
Grip strength by 12 weeks
Continued weakness with sensory symptoms likely a transligamentous motor branch.
318
Endoscopic vs open carpal tunnel?
Endo: lower post-op pain, higher risk of nerve injury, 44% more expensive
319
Ligament vs. Arcade of struthers
Ligament: Median
Arcade: Ulnar (both start with vowels)
320
Types of thumb CMC fracture?
Extra articular
```
Particular articular (Bennett) - stable piece connected to trapezium via anterior oblique ligament
Complete articular (Rolando)
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321
Deforming forces of base of thumb metacarpal fractures?
Adductor pollicis (adduction and supination) - ulnar nerve
APL (radial and proximal) - radial nerve (PIN)
322
Healing of scaphoid fractures by pattern?
Distal pole > Waist > Proximal pole
Oblique > transverse
323
Acute scaphoid fracture management?
Stable waist/distal pole - nondisplaced no diff in LAC, SAC, thumb spica (Doornberg JOT 2011 meta analysis)
Unstable waist - headless compression screw
Proximal pole - always surgery, high non union rate
Relative surgical indicaitons - smokers, delayed presentation
324
Normal distal radius XR parameters?
11-22-11
11-12 mm radial height
22 deg radial inclination
11 deg palmar tilt
325
Acceptable position for distal radius fractures?
< 10 deg dorsal angulation
Radial shortening < 3mm
<2mm joint step off
326
SLAC Wrist arthritis pattern
Stage 1 - Styloid - excision, partial wrist fusion (STT, SC)
Stage 2 - Scaphoradius DJD - scaphoid excision and 4 corner fusion
Stage 3 - Proximal capitate migration, capitolunate DJD - 4 corner fusion or wrist fusion
Stage 4 - Pan carpal DJD - wrist fusion
327
4 corner fusion entails what?
Scaphoid fusion and fusion between Lunate, capitate, hamate, and triquetrum.
328
SLAC reconstruction options
4 corner fusion with scaphoid excision
PRC
With both 50% motion and 50% strength
329
Tendon rupture treatments in RA
EPL rupture - tendon transfer with EIP or ECRL
FPL most common (Mannerfelt) - transfer with FDS to ring, BR or IP joint fusion)
330
Late complication of isolated PCL?
Patellofemoral and medial chondrosis
331
Where do most popliteal cysts occur?
Between the medial head of the gastroc and the semimembranosus
332
What is miserable mal alignment syndrome?
Femoral anteversion, genu valgum, external tibial torsion
