Basic Science Flashcards
What are the 5 (or 7) layers of the growth plate
Reserve Zone (near epiphysis) Proliferative Zone Hypertrophic Zone - Maturation zone - Degenerative zone - Provisional zone (of calcification)
RPM DC
Reserve, Proliferative, Maturation, Degeneration, Calcification
What are the 3 stages of Endochondral fracture healing
Inflammation
Repair
Remodeling
What cell types are involved in the Inflammatory stage of Endochondral fracture healing?
Macrophages Neutrophils Platelets Fibroblasts Mesenchymal cells OsteoBlasts FibroBlasts
Main collagen type for Ehlers Danlos, Dupuytrens, Bone, Cartilage
BCDE (minus 4)
Bone 1
Cartilage 2
Dupuytrens 3
Ehlers-Danlos 5 (classic type)
4 types of Necrotizing Fasciitis
MultiMicrobial
MonoMicrobial (Usually Group A strep)
Marine (Vibrio vulnificus
MRSA
Name a urine marker of bone turnover
N-telopeptide
What are 5 types of wear in bearing surfaces
Adhesive Abrasive Volumetric Linear Third body
What blood test can be prognostic in Multiple Myeloma
Beta 2 Microglobulin
< 4 = median survival 43 months
> 4 = median survival 12 months
OR
< 3.5 = 62 months
< 5.5 = 44 months
> 5.5 = 29 months
Multiple Myeloma diagnostic criteria
CRAB and MDE (myeloma defining events)
CRAB: hyperCalcaemia Renal insufficiency Anaemia Bone lesions
MDE:
> 60% clonal cells on bone marrow
serum light chain ratio
What does OsteoProteGrin do and how
Inhibits Osteoclast activation and differentiation
Acts as a decoy receptor for RANK-L
What does Insulin-like Growth Factor - 2 do and how
Stimulates bone and cartilage formation
Acts through tyrosine kinase receptors on a variety of cells
What does Platelet Derived Growth Factor do and how
Signals Inflammatory cells to migrate to fracture site
Acts through tyrosine kinase receptors
What does Receptor Activated Nuclear Kappa Ligand do and how
Stimulates bone resorption
Acts through RANK receptors on osteoClasts
What does Bone Morphogenic Protein do and how
Stimulates proliferation and differentiation of pluripotent mesenchymal stem cells into bone forming cells
Acts through serine-threonine kinase receptors
Which bone graft substitute has the highest early compressive strength
Calcium Phosphate
CaPO
It is injected, then hardens into dahllite, which is 4 to 10 times harder than cancellous bone.
What is the name of the process by which primary bone healing occurs
Intramembranous bone healing occurs via Haversian remodelling with cutting cones
Strain <2 %
What is the name of the process by which secondary bone healing occurs
Endochondral bone healing occurs via chondrocyte activity (callus formation)
Strain of 2 to 10 %
Which BMPs are osteoinductive
BMP 2, 6 and 9 induce osteoblast differentiation
Which BMP has no osteoinductive or osteogenic activity
BMP 3
Demineralized Bone Matrix is Osteo(?inductive, ?conductive, ?genic)
Osteoconductive - contains collagen and calcium
Osteoinductive - contains BMPs and TGF-B
Has no stem cells and has no structural support
6 factors that lead to Catastrophic wear in TKA
Thickness of PE Surface design Kinematics Sterilization of PE Manufacturing of PE Technique (tight flexion gap, tight PCL, anterior slope)
6 factors that lead to Catastrophic wear in TKA
Thickness of PE (< 8 mm) Surface design Kinematics (varus alignment) Sterilization of PE Manufacturing of PE Technique (tight flexion gap, tight PCL, anterior slope)
Synovial WBC values in infected TKA, THA, acute and chronic
Infected if:
1100 in TKA > 6 weeks
27800 in TKA < 6 weeks
3000 in THA > 6 weeks
4350 in MoM THA
1166 in THA antibiotic spacers
Aminoglycosides - 1. Static or cidal, 2. type of bacteria, 3. mechanism
BacteriCidal
Aerobic
Gram -ve
30S ribosomal subunit
Quinolones - 1. Static or cidal, 2. type of bacteria, 3. mechanism
Mostly BacteriStatic
Broad spectrum
interfere with bacterial topoisomerase IV and DNA gyrase
Workup for Tuberculosis
Mycobacterium tuberculosis
Granulomatous infection
CXR
Mantoux
Quanterferon gold
Acid fast bacilli on cultures
Treat when RIPE
Rifampicin
Isoniazid
PyraZinaMide
Ethambutol
CRPS major and minor criteria
Major: Intense and prolonged pain Swelling Stiffness Discoloration
Minor: Trophic changes Osseous demineralization Temperature changes Palmar fibromatosis
