Basic Science Flashcards
Types of bone (2)
- Lamellar
2. Woven
Subtypes of Lamellar Bone (2)
- Cortical
2. Cancellous
Subtypes of Woven Bone (2)
- Immature
2. Pathologic
_____ bone is stress-oriented. _____ bone is not.
Lamellar
Woven
Cortical bone constitutes ____% of skeleton.
80%
These cells form bone by generating organic, non-mineralized matrix.
Osteoblasts
Osteoblasts are derived from these.
Undifferentiated mesenchymal stem cells.
This transcription factor directs mesenchymal cells to the osteoblast lineage.
RUNX2
Osteoblasts have more of these organelles than do most other cells (3).
- Endoplasmic reticulum
- Golgi apparatus
- Mitochondria
Osteoblast receptors (5).
- PTH
- 1,25 (OH)2 Vitamin D3
- Glucocorticoids
- Prostaglandins
- Estrogen
Osteoblasts produce (5).
- Alkaline phosphatase
- Osteocalcin
- Type I collagen
- Bone sialoprotein
- RANKL
Osteoblasts are stimulated by ______ exposure to PTH.
intermittent (pulsatile)
Osteoblast activity inhibited by ____.
TNF-alpha
These cells maintain bone.
Osteocytes.
These cells constitute 90% of cells in the mature skeleton.
Osteocytes.
Osteocytes have _____ nuclear/cytoplasmic ratio.
high
Osteocytes are important for extracellular concentrations of these.
Calcium and Phosphorous.
Osteocytes are directly stimulated by _____.
calcitonin
Osteocytes are inhibited by _____.
PTH.
These cells resorb bone.
Osteoclasts.
Osteoclast description.
Multinucleated, irregular giant cells.
Osteoclasts are derived from this lineage.
Hematopoietic cells in macrophage line.
Purpose of osteoclast ruffled border.
Increase surface area for resorption.
Location of bone resorption.
Howship’s lacunae.
These proteins allow osteoclasts to bind to bone surfaces.
Integrins.
This osteoclast protein produces acidic environment for bone resportion.
Carbonic anhydrase.
Acidity effect on hydroxyapatite.
Increases solubility.
This lysosomal enzyme digests organic bone matrix.
Cathepsin K.
Calcitonin effect.
Inhibition of osteoclastic resorption.
Effect of IL-1 on bone.
Stimulates osteoclast differentiation and bone resorption.
Effect of IL-10 on osteoclasts.
Suppresses them.
Bisphosphonates do this.
Inhibit osteoclastic bone resorption.
Categories of bisphosphonates (2).
- Nitrogen-containing.
2. Non-nitrogen-containing.
Examples of nitrogen-containing bisphosphonates (2).
- Zoledronic acid (Zometa)
2. Alendronate (Fosamax)
Nitrogen-containing or non-nitrogen-containing bisphosphonates are more potent? By how much?
Nitrogen-containing, 1000-fold
Mechanism of action of nitrogen-containing bisphosphonates (3).
- Block farnesyl pryophosphate synthase.
- Loss of guanosine triphosphatase (GTPase) formation.
- Ruffled border formation inhibited.
Pathway inhibited by nitrogen-containing bisphosphonates.
Mevalonate pathway.
Mechanism of action of non-nitrogen-containing bisphonsphonates.
Metabolized into a nonfunctional ATP analog, inducing apoptosis.
These medications decrease skeletal events in multiple myeloma.
Bisphosphonates.
These medications are associated with osteonecrosis of the jaw.
Bisphosphonates.
Bisphosphonates have this effect on spinal fusion in animal model.
Reduced rate of fusion.
Types of bone matrix (2).
- Organic
2. Inorganic
Components of organic bone matrix (4).
- Collagen
- Proteoglycans
- Non-collagenous matrix proteins
- Growth factors and cytokines
Collagen constitutes ___% of the organic bone matrix.
90%
Function of collagen in organic bone matrix.
Provides tensile strength.
Function of proteoglycans in bone matrix.
Compressive strength.
Noncollagenous bone matrix proteins (3).
- Osteocalcin
- Osteonectin
- Osteopontin
Most abundant noncollagenous bone matrix protein.
Osteocalcin.
Function of osteocalcin.
Attracts osteoclasts.
Function of osteopontin.
Cell-binding protein, similar to an integrin.
Examples of growth factors and cytokines in bone (5).
- TGF-beta
- IGF
- IL-1
- IL-6
- BMPs
Most of inorganic bone matrix composed of this.
Calcium hydroxyapatite.
Components of inorganic bone matrix (2).
- Calcium hydroxyapatite
2. Osteocalcium phosphate
Formula of calcium hydroxyapatite.
Ca10(PO4)6(OH)2
Function of calcium hydroxyapatite.
Compressive strength.
Collagen type in bone.
Type I.
Collagen cross-linking effects (2).
- Decreases collagen solubility.
2. Increases tensile strength.
Regulators of osteocalcin (2).
- Inhibited by PTH
2. Stimulated by 1,25-dihydroxyvitamin D3
This protein can be measure in serum or urine as a marker of bone turnover.
Osteocalcin.
Inorganic components of bone comprise ___% of the dry weight of bone.
60%
Wolff’s law.
Bone remodelling occurs in response to mechanical stress.
Hueter-Volkmann law.
Compressive forces inhibit bone growth, tension stimulates it.
Bone receives ___% to ___% of cardiac output.
5-10%.
Long bones receive blood from three sources (3).
- Nutrient artery system
- Metaphyseal-epiphyseal system
- Periosteal system
Direction of arterial flow in mature bone is ____.
Centrifugal (inside to outside).
Blood pressure in the nutrient artery system is ____.
High.
Blood pressure in the periosteal system is ____.
Low.
Blood flow direction in fractured bone.
Centripetal (outside to inside).
Venous flow direction in mature bone.
Centripetal (outside to inside).
Inner periostem.
Cambium.
Red marrow composition (3).
- 40% water
- 40% fat
- 20% protein
Yellow marrow composition (3).
- 15% water
- 80% fat
- 5% protein
Types of ossification (3).
- Enchondral
- Intramembranous
- Appositional
Bone replaces cartilage model.
Enchondral ossification.
Embyronic formation of long bones is this type of ossification.
Enchondral ossification.
Longitudinal physeal growth is this type of ossification.
Enchondral ossification.
Fracture callus is this type of ossification.
Enchondral ossification.
Bone formed with demineralized bone matrix is this type of ossification.
Enchondral ossification.
Major source of nutrition of the growth plate.
Perichondral artery.
Multiple epiphyseal dysplasia affects the _____.
Epiphysis.
Spondyloepiphyseal dysplasia affects growth at the _____.
Physis.
Acromegaly affects growth at the ____.
Physis.
In this physeal zone, cells store lipids, glycogen, and proteoglycan aggregates.
Reserve zone.
Lysosomal storage diseases affect this physeal zone.
Reserve zone.
Physeal zone characterized by matrix production, stacking of chondrocytes, and longitudinal growth.
Proliferative zone.
Achondroplasia causes defects in this physeal zone.
Proliferative zone.
Growth hormone exerts effects in this physeal zone.
Proliferative zone.
These make up the hypertrophic zone (3).
- Maturation
- Degeneration
- Provisional calcification
Normal matrix mineralization occurs in this physeal zone.
Hypertrophic zone.
This physeal zone widens in rickets.
Hypertrophic zone.
Enchondromas originate in this physeal zone.
Hypertrophic zone.
SCFE occurs in this physeal zone.
Hypertrophic zone.
Supplies chondrocytes to the periphery for lateral growth (width).
Groove of Ranvier.
Dense fibrous tissue anchoring the periphery of the physis.
Perichondrial ring of La Croix.
Undifferentiated mesenchymal cells aggregate into layers, differentiate into osteoblasts, and deposit an organic matrix that materializes.
Intramembranous ossification.
Embryonic flat bone formation is an example of this.
Intramembranous ossification.
Bone formation during distriction osteogenesis is an example of this.
Intramembranous ossification.
Blastema bone in young children with amputations is an example of this.
Intramembranous ossification.
Periosteal bone enlargement (width) is an example of this type of ossification.
Appositional ossification.
This protein stimulates bone formation by inducing metaplasia of mesenchymal cells into osteoblasts.
Bone morphogenic proteins (BMP).
BMP-2 use.
Acute open tibia fractures.
BMP-7 use.
Tibial non-unions.
BMP-3 use.
No osteogenic activity.
Cyclooxygenase-2 (COX-2) activity is required for this.
Normal enchondral ossification.
These antibiotics are toxic to chondrocytes and inhibit fracture healing.
Quinolones.
Fresh frozen allograft preserves ____.
BMP
Cortical allograft has ____ incorporation compared to cancellous.
Slower.
Fresh allograft has the highest _______ of the allograft types.
Immunogenicity.
Osteoconductive matrix.
Acts as a scaffold or framework for bone growth.
Osteoinductive factors.
Growth factors that stimulate bone formation (BMP).
Osteogenic cells.
Primitive mesenchymal cells, osteoblasts, osteocytes.
Demineralized bone matrix is _____ and _____.
Osteoconductive and osteoinductive.
Calcium is absorbed in this area of the GI tract.
Jejunum.
Calcium is absorbed in the gut by this mechanism.
Passive diffusion.
Calcium is filtered by the glomeruli and then ____.
Reabsorbed.
This percentage of calcium is reabsorbed by the kidneys.
98%
Primary regulators of serum calcium (2).
- PTH
2. 1,25(OH)2-vitamin D3
Dietary requirement of elemental calcium for children.
600 mg/day
Dietary requirement of elemental calcium for adolescents and young adults.
1300 mg/day
Dietary requirement of elemental calcium for adults.
750 mg/day
Dietary requirement of elemental calcium for postmenopausal women.
1500 mg/day
Dietary requirement of elemental calcium for lactating women.
2000 mg/day
Dietary requirement of elemental calcium for pregnant women.
1500 mg/day
Dietary requirement of elemental calcium for patients healing fracture in long bone.
1500 mg/day
This percentage of body’s phosphate stored in bones.
85%
Majority of calcium absorbed in this area of the kidney.
Proximal tubule.
Daily phosphate requirement.
1000 to 1500 mg.
PTH is comprised of ____ amino acids.
84
PTH is synthesized and secreted from here.
Chief cells of the parathyroid glands.
The active portion of PTH.
The N-terminal fragment (1-34).
Synthetic form of recombinant human PTH.
Teriparatide.
Effect of PTH is mediated by this mechanism.
cAMP.
Calcitonin is produced here.
Clear cells in parafollicles of the thyroid gland.
Active form of vitamin D.
1,25(OH)2-vitamin D3
Inactive vitamin D metabolite.
24,25(OH)2-vitamin D3
25-OHase is located here.
Liver.
1-OHase is located here.
Kidney.
Corticosteroids affect bone mineralization. True or False.
False.
Effects of corticosteroids on bone (2).
- Decreased gut absorption of calcium by decreased binding proteins.
- Inhibition of collagen synthesis.
Peak bone mass occurs between these ages.
16-25 years.
After peak, bone loss occurs at a rate of ____ to ____ per year.
0.3 to 0.5% per year
Rate of bone loss in women 6 - 10 years after menopause.
2-3% per year
Osteoporotic long bones have ______ inner diameter and _____ outer diameter.
Increased inner and outer diameters.
Elevated in urine when bone resorption occurs.
Hydroxyproline.
Brown tumors.
Primary hyperparathyroidism.
Pseudohypoparathyroidism.
PTH receptor abnormality.
Type I hereditary vitamin-D dependent rickets.
Defect in renal 1-alpha hydroxylase.
Type II hereditary vitamin-D dependent rickets.
Defect in intracellular receptor for 1,25(OH)2-Vitamin D.
Most commonly encountered form of rickets.
Hypophosphatemic rickets.
Hypophosphatemic rickets.
Inborn error of phosphate transport causing failure of phosphate reabsorption in the kidney.
Chronically elevated serum PTH results in.
Secondary hyperparathyroidism with hyperplasia of chief cells of parathyroid gland.
Causes of rickets and osteomalacia (5).
- Nutritional deficiency
- Phosphorous deficiency
- GI absorption defects
- Renal tubular defects
- Renal osteodystrophy
Rickets.
Failure of mineralization, leading to changes in the physis in the zone of provisional calcification.
Serum calcium level in nutritional rickets.
Low-normal (maintained by high PTH).
Serum phosphate level in nutritional rickets.
Low (excreted due to effect of PTH).
Alkaline phosphatase level in nutritional rickets.
Increased.
Vitamin D level in nutritional rickets.
Low.
PTH level in nutritional rickets.
Increased (leads to increased bone resorption).
Types of hereditary vitamin D dependent rickets.
- Type I – Defect in renal 25(OH) 1alpha-hydroxylase
2. Type II – Defect in intracellular receptor of 1,25(OH) - Vitamin D
Inheritance pattern of familial hypophosphatemic rickets.
X-linked dominant.
Vitamin D - resistant rickets.
Familial hypophosphatemic rickets.
Mechanism of hypophosphatemic rickets.
Impaired renal tubular reabsorption of phosphate.
Treatment of familial hypophosphatemic rickets.
- Phosphate replacement
2. High dose vitamin D3
Inheritance pattern of hypophosphatasia.
Autosomal recessive.
Error in tissue-nonspecific isoenzyme of anklaline phosphatase.
Hypophosphatasia.
Diagnosis of hypophosphatasia.
Increased urinary phosphoenthanolamine.
This process remains normal in osteoporosis.
Mineralization
WHO definition of osteoporosis.
L2-L4 bone density 2.5 or more standard deviations less than peak bone mass of healthy 25 year old. (T-score)
WHO definition of osteopenia.
Bone density 1.0 to 2.5 standard deviations less than mean peak bone mass of healthy 25 year old. (T-score)
Risk for second vertebral osteoporotic compression fracture after the first.
20%
Lifetime risk of fracture in white women after 50 years of age.
75%
Life risk of hip fracture in white women after 50 years of age.
15-20%
Type I osteoporosis.
Post-menopausal.
Type II osteoporosis.
Age-related.
Plain radiographs may be normal in osteoporotic patients until decrease in bone mass exceeds this value.
30%
DEXA stands for.
Dual-energy x-ray absorptiometry.
Histologic changes in osteoporosis (3).
- Thinning trabeculae
- Decreased osteon size
- Enlarged haversian and marrow spaces
Defect of bone mineralization in adults.
Osteomalacia.
Histologic finding in osteomalacia.
Widened osteoid seams.
Causes a decrease in chondroitin sulfate synthesis.
Vitamin C (ascorbic acid) deficiency.
Defects in vitamin C deficiency (2).
- Defective collagen growth and repair
2. Impaired intracellular hydroxylation of collagen peptides.
Physis histology with vitamin C deficiency.
Widening of zone of provisional calcification.
Failure of normal collagen cross-linking as a result of glycine substitutions in pro-collagen.
Osteogenesis imperfecta.
Albers-Schonberg disease.
Benign osteopetrosis.
Rugger jersey spine.
Osteopetrosis.
Articular cartilage receives nutrients and oxygen primarily through this mechanism.
Diffusion.
pH of cartilage.
7.4
Composition of articular cartilage.
- Water 65-80%
- Collagen 10-20%
- Proteoglycans 10-15%
- Chondrocytes 5%
This amino acid is unique to collagen.
Hydroxyproline.
95% of collagen in articular cartilage.
Type II.
Type of collagen produced by chondrocytes during enchondral ossification.
Type X.
Subtypes of glycosaminoglycans (2).
- Chondroitin sulfate
2. Keratin sulfate
Master switch of chondrocytes.
SOX9 transcriptional factor.
Chondrocytes are least active in this zone.
Calcified zone.
Articular cartilage layers (5).
- Gliding zone (superficial)
- Transitional zone (middle)
- Radial zone (deep)
- Tidemark
- Calcified zone
Articular cartilage gliding zone function.
Opposes shear.
Articular cartilage transitional zone function.
Opposes compression.
Articular cartilage radial zone function.
Opposes compression.
Articular cartilage tidemark zone function.
Opposes shear.
Articular cartilage calcified zone function.
Anchor.
Superficial articular cartilage zone.
Gliding zone.
Middle articular cartilage zone.
Transitional zone.
Deep articular cartilage zone.
Radial zone.
Orientation of collagen in the gliding articular cartilage zone.
Tangential.
Orientation of collagen in the transitional articular cartilage zone.
Oblique.
Orientation of collagen in the radial articular cartilage zone.
Vertical.
Predominant mechanism of lubrication during dynamic joint function.
Elastohydrodynamic lubrication.
The peripheral ____% of the meniscus is supplied by vessels. The remainder receives nutrition through ____.
25%, diffusion
This cell type is responsible for meniscal healing.
Fibrochondrocyte.
These meniscus tears heal the best.
Peripheral, acute with rim width larger than 4mm.
Osteoarthritis cartilage has _____ water content.
Increased.
Chondroitin/keratin sulfate ratio in osteoarthritis cartilage.
Increased.
Most common cause of upper extremity neuropathic arthropathy.
Syringomyelia.
Technitium bone scan in Charcot arthropathy.
May be positive in both infection and Charcot.
Indium leukocyte scan in Charcot arthropathy.
Negative in Charcot. Positive in osteomyelitis.
Degenerative arthritis resulting from alkaptonuria.
Ochronosis.
The most common inflammatory arthritis.
Rheumatoid arthritis.
Conditions in which rheumatoid factor may be positive (4).
- Rheumatoid arthritis
- Sjogren’s syndrome
- Sarcoid
- SLE
Conditions in which ANA may be positive (3).
- SLE
- Sjogren’s syndrome
- Scleroderma
Primary cellular mediators of tissue destruction in RA.
Mononuclear cells.
RF is directed against this molecule.
IgG.
RF is most commonly this type of immunoglobulin.
IgM.
Acute-onset juvenile RA with fever, rash, and splenogmegaly.
Still’s disease.
Mortality in SLE is related to ____ involvement.
Renal.
Butterfly malar rash.
SLE.
Most common feature of SLE.
Joint involvement.
Aching and stiffness of the shoulder and pelvic girdle.
Polymyalgia rheumatica.
Has an association with temporal arteritis.
Polymyalgia rheumatica.
Marginal syndesmophytes.
Ankylosing spondylitis.
Conjunctivitis, urethritis, and oligoarticular arthritis.
Reiter’s syndrome.
Sausage digits.
Psoriatic arthropathy.
Pencil-in-cup deformity.
Psoriatic arthropathy.
Monosodium urate crystal deposition.
Gout.
Second most affected organ in gout.
Kidneys.
Thin, negatively birefringent crystals.
Monosodium urate.
Mechanism of allopurinol.
Xanthine oxidase inhibitor.
Xanthine oxidase is needed for these reactions (2).
- Hypoxanthine to xanthine
2. Xanthine to uric acid
Calcium pyrophosphate deposition.
Pseudogout.
Short, rhomboid-shaped positively birefringent crystals.
Calcium pyrophosphate.
The crystal is blue when long axis of the crystal in parallel to the compensator of the microscope.
Positive birefringence.
The crystal is yellow when long axis of the crystal in parallel to the compensator of the microscope.
Negative birefringence.
Borrelia burgdorferi causes this disease.
Lyme disease.
Recurrent knee effusion with history of erythema migrans.
Lyme disease.
Lyme disease treatment.
Doxycycline
Hemophilic arthropathy associated with these deficiencies (2).
- Factor VIII deficiency
2. Factor IX defeciency
Most characteristic organism causing osteomyelitis in sickle cell patients.
Salmonella.
Most common organism causing osteomyelitis in sickle cell patients.
Staphylococcus.
Pigmented synovial histiocytes.
PVNS
Sarcomere lines and bands (5).
- Z line
- M line
- H band
- I band
- A band
Surrounds individual muscle bundles.
Epimysium.
Surrounds muscle fascicles.
Perimysium.
Surrounds individual fibers.
Endomysium.
Contains only myosin (thick) filaments.
H-band.
Contains only actin (thin) filaments.
I-band.
Lies between I bands and contains the H-band.
A band.
Thin (actin) filaments are attached to this.
Z-line.
Shortage of acetylcholine receptors.
Myesthenia gravis.
Blocks presynaptic acetylcholine release.
Botulinum toxin.
Troponin is located on actin or myosin?
Actin (thin filaments).
Constant muscle tension
Isotonic.
Muscle length remains unchanged.
Isometric.
Muscle contracts at constant velocity.
Isokinetic.
Type I muscle fibers (3).
- Slow twitch
- Oxidative
- Red
Type II muscle fibers (3).
- Fast twitch
- Glycolytic
- White
Muscle energy systems (3) and time courses.
- ATP-creatine phosphate system (10-20 sec)
- Lactic anaerobic system (20-120 sec)
- Aerobic system (longer duration)
Female athlete triad (3)
- Amenorrhea
- Osteoporosis
- Anorexia
Most common sports injury.
Muscle strain.
Muscle strains occur at this location in these muscles.
Myotendinous junction, muscle crossing two joints
Hypotension with bradycardia.
Spinal (neurogenic) shock.
These nerve fibers originate in receptors in muscle, skin, and sense organs of the head.
Somatic afferent fibers.
These cells are responsible for myelinating peripheral nerve axons.
Schwann cells.
Meissner’s corpuscle detects ____.
touch
Pacini’s corpuscle detects ____.
flutter
Ruffini’s corpuscle detects _____.
vibration
Merkel’s receptor detects _____.
Steady skin indentation
Gaps between Schwann cells.
Nodes of Ranvier.
Complete nerve division with disruption of the endoneurium.
Neurotmesis.
Disruption of the axon and myelin sheath but leaving epineurium intact.
Axonotmesis.
Selective demylination of the axon sheath, generally due to local ischemia.
Neurapraxia.
First sensation to return after nerve injury.
Pain.
In brachial plexus injury, positive histamine response implies this.
That reflex arc is intact.
A positie histamine response indicates that the lesion is proximal to this location.
Ganglion (preganglionic).
Predominant cell type in tendons.
Fibroblasts.
Early tendinous healing with this type of collagen.
Type III.
After surgical repair, tendon is weakest at this timepoint.
7-10 days
Maximum tendon strength achieved at this time post repair.
6 months
Most of original tendon strength regained at time period after repair.
21-28 days
The two types of ligament insertion.
- Acute angles into periosteum
2. 90 degree angle into bone
Two components of the intervertebral disc (2).
- Central nucleus pulposus
2. Surrounding annulus fibrosis
Content of nucleus pulposus.
High glycosaminoglycan/low collagen
Content of annulus fibrosis.
High collagen/low glycosaminoglycan
How intervertebral discs obtain nutrition.
Diffusion through hyaline cartilage endplates.
Aging intervertebral discs have decreased ___ content.
water
Aging discs have a decrease in the concentration of this molecular and increase in the concentration of thi molecule.
Decrease in proteoglycan concentration.
Increase in keratin sulfate concentration.
Osteoarticular allografts preserved with cryopreservation.
No viable chondrocytes after clinical preservation.
Method of allograft preservation in which there is a controlled rate freezing in a protective medium.
Cryopreservation.
Synthetic ligaments are associated with these.
Sterile joint effusions.
Identifies a particular DNA sequence in an extract of mixed DNA.
Southern blotting.
Identifies a particular RNA sequence in an extract of mixed RNA.
Northern blotting.
Identifies a particular protein in an extract of mixed proteins.
Western blotting.
Used to reverse transcribe RNA to complementary DNA.
Reverse transcriptase.
The production of genetically identical biologic entities.
Cloning.
Cell involved in specific immune responses (2).
B and T cells.
Adaptive immune response broken down into these two.
- Cell mediated
2. Humoral
B lymphocytes mature here.
Lymph nodes.
T lymphocytes originate here.
Bone marrow.
Immune responses are evoked by these.
Antigens.
Five classes of immunoglobulins.
- IgA
- IgM
- IgG
- IgD
- IgE
Growth control genes
Oncogenes
Tumor supressor genes
Antioncogenes
Most common sites of primary tumors that metastasize to bone (5).
- Breast
- Prostate
- Lung
- Kidney
- Thyroid
Quantify the amount of DNA in cells.
Flow cytometry.
Modes of mendelian inheritance (4).
- Autosomal dominant
- Autosomal recessive
- X-linked dominant
- X-linked recessive
All daughters of an affected father have the trait but no sons.
X-linked dominant.
Genetic disease becomes progressively more severe in each subsequent generation.
Anticipation.
Abnormal number of chromosomes.
Aneuploidy.
Three copies of chromosomes.
Triploidy.
One chromosome pair has an extra chromosome.
Trisomy.
A section of one chromosomes is absent.
Deletion.
Extra section of one chromosome is present.
Duplication.
Portion of one chromosome is exchanged with a portion of another chromosome.
Translocation.
Broken portion of a chromosome reattaches to the same chromosome in the same location but reverse direction.
Inversion.
Inheritance pattern of achondroplasia.
Autosomal dominant.
Inheritance pattern of diastrophic dysplasia.
Autosomal recessive.
Inheritance pattern of McCune-Albright syndrome.
Sporadic mutation.
Inheritance pattern of multiple epiphyseal dysplasia.
Autosomal dominant.
Inheritance pattern of hypophasphatemic rickets.
X-linked dominant.
Inheritance pattern of hereditary vitamin D-dependent rickets.
Autosomal recessive.
Inheritance pattern of Marfan’s syndrome.
Autosomal dominant.
Inheritance pattern of Ehlers-Danlos syndrome.
Autosomal dominant.
Inheritance pattern of Duchenne’s muscular dystrophy.
X-linked recessive.
Inheritance pattern of Becker’s muscular dystrophy.
X-linked recessive.
Inheritance pattern of hemophilia A and B.
X-linked recessive.
Inheritance pattern of sickle cell anemia.
Autosomal recessive.
Inheritance pattern of Gaucher’s disease.
Autosomal recessive.
Inheritance pattern of hemochromatosis.
Autosomal recessive.
Inheritance pattern of Charcot-Marie-Tooth disease.
Autosomal dominant.
Inheritance pattern of neurofibromatosis.
Autosomal dominant.
Streptococcus viridans source.
Human bite.
Pasteurella canis source.
Dog bite.
Pasteurella multocida source.
Cat bite.
Most common risk factor for necrotizing fasciitis.
Diabetes.
Types of necrotizing fasciitis infections (4).
- Type 1 - polymicrobial
- Type 2 - group A beta-hemolytic strep
- Type 3 - marine vibrios
- Type 4 - MRSA
Characteristic osteomyelitis organism of sickle cell anemia.
Salmonella.
Nail through sole of shoe.
Pseudomonas aeruginosa.
HIV risk of seroconversion from contaminated needle stick.
0.3%
Risk of HIV transmission through blood transfusion.
1/500,000 per unit transfused.
Cat scratch fever organism.
Bartonella henselae.
Cat scratch fever treatment.
Azithromycin.
Inhibit cross-linking of polysaccharides in the cell wall by blocking transpeptidase enzyme.
Beta-lactams.
Beta-lactam antibiotic examples (2).
- Penicillin
2. Cephalosporins
Inhibit protein synthesis through binding to 30S-ribosomal subunit.
Aminoglycosides.
Aminoglycoside examples (2).
- Gentamicin
2. Tobramycin
Inhibit dissociation of peptidyl-transfer RNA from ribosomes during translocation (50S-ribosomal subunit).
Clindamycin and macrolides.
Examples of macrolides (3).
- Erythromycin
- Clarithromycin
- Azithromycin
Vancomycin mechanism.
Interfere with insertion of glycan subunits into cell wall.
Inhibits RNA polymerase F.
Rifampinin.
Inhibit DNA gyrase.
Quinolones.
This amount of antibiotic powder in cement does not affect the compressive strength of the PMMA.
2g abx per 40g powdered PMMA
Virchow’s triad.
- endothelial damage
- venous stasis
- hypercoagulability
Gold standard for diagnosing DVT.
Venography.
Warfarin mechanism of action.
Inhibition of vitamin K 2,3-epoxide reductase in the liver.
Total lymphocyte count threshold to promote healing.
1500/mm3
Transcutaneous oxygen level above this threshold promotes healing.
30mmHg
Treatment for malignant hyperthermia.
Dantrolene sodium.
First signs of malignant hyperthermia (2).
- Increased end-tidal Co2
2. Tachycardia
Gold standard for neuromonitoring intraop.
Wake up test.
These herbal medicines increase the risk of perioperative bleeding (3).
- Garlic
- Ginkgo biloba
- Ginseng
Technitium bone scan detects (3).
- Infection
- Trauma
- Tumor
Phases of three phase bone scans.
- Blood flow, immediate
- Blood pool, 30 min
- Delayed, 4 hrs
Indium scans are specific for.
Inflammation.
Type of stainless steel used in orthopaedic implants.
316L
Elements found in stainless steel (6).
- Iron
- Carbon
- Chromium
- Nickel
- Molybdenum
- Manganese
Healing below melting point.
Annealing.
Polyethylene particles of this size are most reactive.
0.1 - 1.0 micrometers
Main determinant of elastic modulus of cortical bone.
Mineral content.
Distance between threads in a screw.
Pitch.
To maximize pullout strength of screw (3).
- Large outer diameter
- Small root diameter
- Fine pitch
Nail bending rigidity related to this.
4th power of nail’s radius.
Force within a joint in response to forces acting on the joint.
Joint reaction force.
Coefficient of friction for human joints.
0.002 to 0.04
Coefficient of friction for metal-on-poly.
0.05 to 0.15
Primary lubrication mechanism for articular cartilage during dynamic function.
Elastohydrodynamic lubrication.
Screw home mechanism of knee.
External tibial rotation during last 15 degrees of extension.
This characteristic of the knee increases maximum knee flexion.
Posterior rollback.
Amount of rotation through C1-C2.
45 degrees.
Amount of rotation through subaxial cervical spine.
10 degrees.
Spine coupled motion.
Axial rotation with lateral bending.
Glenohumeral abduction.
120 deg
Scapulothoracic shoulder abduction.
60 deg.
Most important static stabilizer of the shoulder.
Inferior glenohumeral ligament.
Glenohumeral arthrodesis position (3).
15-20 deg abduction
20-25 deg forward flexion
40-50 deg internal rotation
Humeral head inclination
125 deg
Humeral head position relative to shaft
25 deg retroversion
Functional elbow ROM.
30-130.
Elbow carrying angle for men and women.
Men 7 deg, women 13 deg.
