Orthopedics, which is a branch of clinical medicine that specializes in the diagnosis and treatment of musculoskeletal disease and trauma in the spine and extremities, owes its current status of advanced care to the development of biomaterial science more than any other clinical medical specialty

1. Biomaterials in Orthopedics
Group number
Biomaterials in Orthopedics

2. Agenda
Introduction
Basic concepts and definitions
Biomaterial classification
Orthopedic biomaterials applications
Complications associated with biomaterials
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3. Introduction
Orthopedics, which is a branch of clinical medicine that
specializes in the diagnosis and treatment of musculoskeletal
disease and trauma in the spine and extremities, owes its
current status of advanced care to the development of
biomaterial science more than any other clinical medical
specialty
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4. Topic One
Basics

5. Basic biomaterial concept

6. Young’s Modulus
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Material Properties - Basic Science - Orthobullets
1) Ceramic (Al2O3)
2) Alloy (Co-Cr-Mo)
3) Stainless Steel
4) Titanium
5) Cortical bone
6) Matrix polymers
7) PMMA
8) Polyethylene
9) Cancellous bone
10) Tendon / ligament
11) Cartilage

7. Chart
0
50
100
150
200
250
300
UHMW PMMA bone
cement
Bone cP-Ti Ti-alloy Stainless Steel Co-Cr-Mo alloy
Elastic
Modulus
Series 1 Column1 Column2
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8. Biomaterial Classification
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First
Generation
• Bio-inert materials
• Metallic, ceramic(alumina, zirconia),
polymers
Second
Generation
• Bioactive and biodegradable materials
• Glass ceramics, calcium phosphates,
resorbable polymers
Third
Generation
• Materials designed to stimulate specific
cellular response at molecular level

9. Biomaterials used in orthopedics
• Metal and metal alloys
• Ceramics and ceramometallic(ceramic + metals) materials
• Tissue adhesives
• Bone replacement materials
• Carbon materials and composites, polymers
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10. Common implant material used in
orthopedics
• Metal alloys:
• Stainless steel
• Titanium alloys
• Cobalt chrome alloys
• Non metals:
• Ceramics & bioactive glasses
• Polymers (bone cement, polyethylene)
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11. Ideal implant material
• Chemically inert
• Non-toxic to the body
• Great strength
• High fatigue resistance
• Low elastic modulus
• Absolutely corrosion proof
• Good wear resistance
• Inexpensive
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12. Stainless Steel
C O M P O S I T I O N
 Iron (62.97%)
 Chromium (18%)
 Nickel (16%)
 Molybdenum (3%)
 Carbon (0.03%)
F I R S T G E N E R AT I O N
• Widely used in traumatological
temporary devices such as
fracture plates, screws and hip
nails among others, owing to their
relatively low cost, availability and
easy processing.
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13. Stainless Steel
AD VA N TA G E S
• Relatively ductile
• Biocompatibility
• Relatively cheap
• Reasonable corrosion resistance
• Strong
• Used in plates, screws, IM nails, external
fixators
D I S AD VA N TA G E S
• Poor wear resistance
• Hight young's modulus – 200 G pascals
(10x that of bone)
• Stress shielding of surrounding bone and
bone resorption
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Commonly used is 316L (3% molybdenum, 16% nickel & L = Low carbon content)

14. Titanium alloys
C O M P O S I T I O N
• Titanium (89%)
• Aluminum (6%)
• Vanadium (4%)
• Others (1%)
• Most common orthopedic titanium alloy is
TITANIUM 64 (Ti-6Al-4v)
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15. Titanium alloys
Advantages:
 Corrosion resistant
 Excellent biocompatibility
 Ductile
 Fatigue resistant
 Low young’s modulus
 MR scan compatibility
 Osseointegration
Disadvantages:
 Poor wear characteristics
 Systemic toxicity – vanadium
 Relatively expensive
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16. Cobalt chrome alloys
• Contains primarily cobalt (30-60%)
• Chromium (20-30%) added to
improve corrosion resistance
• Minor amounts of carbon, nickel and
molybdenum added
• Uses:
• For bearing surfaces
• THR
• Metal on metal devices
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17. The implant bearing surfaces
M E TAL O N P O LY E T H Y L E N E M E TAL O N M E TAL
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18. Cobalt chrome alloys
AD VA N TA G E S
• Excellent resistance to corrosion
• Excellent long term biocompatibility
• Strength (very strong)
D I S AD VA N TA G E S
• Very high young’s modulus
• Risk of stress shielding
• Expensive
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19. Comparison of metal alloys
Young’s modulus
(GPa)
Yield Strength (MPa)
Ultimate tensile
strength (MPa)
Stainless Steel 316L 190 500 750
Titanium 64 110 800 900
Cobalt chrome F562 230 1000 1200
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ALLOY

20. Bioactive implants
• Coating of implant with a bioactive ceramic (HA and BGs)
• To chemically modify the surface of the material so as to obtain the deposition of a
bioactive ceramic in vivo or to induce proteins and cell adhesion and other
tissue/material interactions.
• Electrophoretic deposition
• Plasma spraying
• Radio frequency or ionic ray sputtering
• Laser ablation or hot isostatic pressure
• All are not cost effective
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21. Ceramics
• Ceramics are refractory polycrystalline compounds
• Usually inorganic
• Highly inert
• Hard and brittle
• High compressive strength
• Generally good electric and thermal insulators
• Good aesthetic appearance
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22. Ceramics
• Compounds of metallic elements etc., aluminum bound ionically or covalently with
non metallic elements
• Common ceramic include:
• Alumina (aluminum oxide)
• Silica (silicon oxide)
• Zirconia (Zirconium oxide)
• Hydroxyapatite (HA)
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23. Ceramics
AD VA N TA G E S
• Chemically inert & insoluble
• Biocompatible
• Strong and osteoconductive
• Low wear resistance
D I S AD VA N TA G E S
• Brittleness
• Very difficult- high melting point
• Very expensive
• High young’s modulus
• Low tensile strength
• Poor crack resistance
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24. Ceramics
• Alumina (inert ceramics):
• Femoral head
• Bone screws and plates
• Porous coating for femoral stems
• Porous spacers
• Knee prothesis
• Zirconia
• Femoral head
• Artificial knee
• Superior wear resistance
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25. PMMA (bone cement) (polymer)
• Mainly used to fix prosthesis in place , can also be used as void fillers
• Available as liquid and powder
• The liquid contains :
• The monomer N, N-dimethyltoluidine (the accelerator)
• Hydroquinone
• The powder contains:
• PMMA copolymer
• Barium or zirconium oxide
• Benzoyl peroxide (catalyst)
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26. Clinical application of orthopedic implants
• Osteosynthesis
• Joint replacements
• Nonconventional modular tumor implants
• Spine implants
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27. Recent advances
• Nickel free metal alloys
• Anti cytokine in the prevention of osteolysis around implants.
• Antibacterial implant.
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28. Summary
Adequate knowledge of implant material is an
essential platform to making best choices for the
implant. Future: to treat muskoskeletal disorders
with particular emphasis on immune modulation
and regenerative medicine. Advances in
biomedical engineering will go a long way in
helping the orthopedic surgeon.
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29. Thank You
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