Biomedical Engineering Exam #2 || with A+ Guaranteed
Solutions.
What are the different types of fracture fixation devices? correct answers - Screws
- Plates
- Intramedullary Rods
- External Fixators
What does the stability of intramedullary rods depend on? correct answers - Mechanical
properties of nail
- Nail fit in IM space
- Mechanical properties of locking screw/bolts
What does the bending and torsional stiffness of intramedullary rods depend on? correct answers
- Nail diameter
- Nail slots
What do stabilizing pins/anchors do? correct answers -resist rotation
-prox and distal ends stay put so displaces less fragments
What are the advantages of external fixators? correct answers - Only technique that allows
stability to be adapted preoperatively, intraoperatively, and postoperatively and
- allows to treat soft tissue injuries while stabilizing complex fractures
What are the limitations of external fixators? correct answers - Compromise of blood supply in
fracture healing zone
- Interfragmentary movement
- Pin site infection
- Creates stress risers in adjacent bone
What is the most common reason for joint replacements? correct answers Arthritis
- Osteoarthritis
- Rheumatoid arthritis
What are the most common types of joint replacements? correct answers Hips and Knees
What are the two classifications of joint replacements? correct answers - Articular surface only
- Articular surface and bone substructure
What structural and functional characteristics must be considered when completing a joint
replacement? correct answers - Provide normal range of motion while transmitting joint forces
- Longevity (last lifetime of patient)
- Biocompatibility
What are the design challenges of joint replacements? correct answers - Biocompatibility
, - Hermeticity
- Structural design
- Delivery system
- Power management
- Detection
- Wireless communication
What is corrosion? How can you reduce it? correct answers Gradual degradation of materials by
electrochemical attack
- Can be reduced by surface oxide films
- Sensitive to wear
- Regeneration times vary by material
What material has the fastest surface oxide film regeneration time? Which has the slowest? Do
you want this to be fast or slow? correct answers Titanium = fastest
Stainless Steel = slowest
* want this to be fast
What is surface modification? What does it improve? correct answers Performed on biomedical
implants to improve:
- Corrosion resistance
- Wear resistance
- Surface texture
- Biocompatibility
What are four common types of surface modification? correct answers - Laser treatment
- chemical treatment
- HA
- add ceramic coating
What are some causes of joint replacements? correct answers - Joint diseases (most common
rheumatoid arthritis)
- Long term wear (ex:osteoarthritis)
- Bone fractures
- Avascular necrosis
- Acute injury
Did the first artificial knee or hip replacement come first? correct answers Knee - 1890
hip- 1891
shoulder -1893
Implants improved due to... (5) correct answers - new, better quality materials
- different fixation methods
- advanced implant design
- advance in properties and coatings
- less invasive techniques
Solutions.
What are the different types of fracture fixation devices? correct answers - Screws
- Plates
- Intramedullary Rods
- External Fixators
What does the stability of intramedullary rods depend on? correct answers - Mechanical
properties of nail
- Nail fit in IM space
- Mechanical properties of locking screw/bolts
What does the bending and torsional stiffness of intramedullary rods depend on? correct answers
- Nail diameter
- Nail slots
What do stabilizing pins/anchors do? correct answers -resist rotation
-prox and distal ends stay put so displaces less fragments
What are the advantages of external fixators? correct answers - Only technique that allows
stability to be adapted preoperatively, intraoperatively, and postoperatively and
- allows to treat soft tissue injuries while stabilizing complex fractures
What are the limitations of external fixators? correct answers - Compromise of blood supply in
fracture healing zone
- Interfragmentary movement
- Pin site infection
- Creates stress risers in adjacent bone
What is the most common reason for joint replacements? correct answers Arthritis
- Osteoarthritis
- Rheumatoid arthritis
What are the most common types of joint replacements? correct answers Hips and Knees
What are the two classifications of joint replacements? correct answers - Articular surface only
- Articular surface and bone substructure
What structural and functional characteristics must be considered when completing a joint
replacement? correct answers - Provide normal range of motion while transmitting joint forces
- Longevity (last lifetime of patient)
- Biocompatibility
What are the design challenges of joint replacements? correct answers - Biocompatibility
, - Hermeticity
- Structural design
- Delivery system
- Power management
- Detection
- Wireless communication
What is corrosion? How can you reduce it? correct answers Gradual degradation of materials by
electrochemical attack
- Can be reduced by surface oxide films
- Sensitive to wear
- Regeneration times vary by material
What material has the fastest surface oxide film regeneration time? Which has the slowest? Do
you want this to be fast or slow? correct answers Titanium = fastest
Stainless Steel = slowest
* want this to be fast
What is surface modification? What does it improve? correct answers Performed on biomedical
implants to improve:
- Corrosion resistance
- Wear resistance
- Surface texture
- Biocompatibility
What are four common types of surface modification? correct answers - Laser treatment
- chemical treatment
- HA
- add ceramic coating
What are some causes of joint replacements? correct answers - Joint diseases (most common
rheumatoid arthritis)
- Long term wear (ex:osteoarthritis)
- Bone fractures
- Avascular necrosis
- Acute injury
Did the first artificial knee or hip replacement come first? correct answers Knee - 1890
hip- 1891
shoulder -1893
Implants improved due to... (5) correct answers - new, better quality materials
- different fixation methods
- advanced implant design
- advance in properties and coatings
- less invasive techniques
