Biomaterials are natural or synthetic substances that can be tolerated by the human body and are commonly used in orthopedic devices. There are three generations of biomaterials: first generation are bioinert materials, second generation are bioactive and biodegradable, and third generation stimulate specific cellular responses. Common biomaterial classes used in orthopedics include metals and alloys, ceramics, tissues adhesives, polymers, and carbon materials. Metals such as stainless steel, titanium, and cobalt chrome alloys are often used due to their strength and biocompatibility. Ceramics like alumina and zirconia are hard and brittle with high compressive strength. Complications can include infection, loosening

1. BIOMATERIALS IN ORTHOPAEDICS
PRESENTER: DR. CH. RAKESH SINGHA
2nd Year PGT
Dept of Orthopaedics, SMCH

2. INTRODUCTION
• Biomaterial is defined as natural or
synthetic substances capable of
being tolerated temporarily or
permanently by the human body.
• These biomaterials can be found in
things such as contact lenses,
pacemakers, heart valves,
orthopedic devices.

3. • The bioactivity of the material can be defined as its ability to bond biologically to
bone.
• Biomaterial have played integral roles in treatment modalities for damaged &
disease human joints & osseous defects.

4. BASIC CONCEPTS & DEFINITION
• Force applied will lead to deformation &
if continued beyond a certain point will
lead to ultimate failure.
• The force per unit area is stress &
deformation is known as strain.

5. • STRENGTH : The degree of resistance to deformation of a material.
• TOUGHNESS : Amount of energy per unit volume that a material can absorb
before failure.
• DUCTILITY/ BRITTLENESS : The amount by which a material deforms
before it breaks.
• HOOKE’S LAW : Stress is directly proportional to strain produced.

6. PROPERTIES OF BIOMATERIALS
• Highly inert.
• Hard but Brittle.
• High compressive state.
• Good electric & thermal insulator.
• Good aesthetic appearance.
• They are lighter than metals.

7. BIOMATERIAL CLASSIFICATION
• First generation :
- Bioinert material
• Second generation :
- Bioactive & Biodegradable material
• Third generation :
- Material designed to stimulate specific response at molecular level.

8. FIRST GENERATION
• Invented in 1980
• Bioinert – minimum immune response & minimum foreign body reaction.
• Same physical properties to match replaced tissue.

9. SECOND GENERATION
• Invented between 1980 – 2000
• Interacts with biological environment.
• Bioactive – it enhances biological response & tissue surface bonding.
• Biodegradable – it undergoes progressive degradation with healing &
regeneration of tissue.

10. THIRD GENERATION
• Invented in 2002
• AIM is to stimulate specific cellular response at molecular level
• Signal & stimulate specific cellular activity.

11. CLINICAL APPLICATION OF ORTHOPAEDIC IMPLANT
• Osteosynthesis
• Joint replacement
• Nonconventional modular tumour
implant
• Spine implant

12. BIOMATERIAL USED IN ORTHOPAEDICS
A) METAL & METAL ALLOYS
B) CERAMICS
C) TISSUE ADHESIVES
D) BONE REPLACEMENT MATERIAL
E) CARBON MATERIAL & POLYMERS

13. COMMON IMPLANT MATERIALS
METAL ALLOYS
• Stainless steel
• Titanium alloys
• Cobalt chrome alloy
NON-METAL
• Ceramics & Bioactive glass
• Polymers (Bone cement,
polyethylene)

14. A) METALS & METAL ALLOYS
1) STAINLESS STEEL:
• Composition :
- Iron
- Chromium
- Nickel
- Molybdenum
- Carbon
• Most commonly used is 316L
- 3%Mb, 16%Nickel, Low carbon

15. Advantages
• Strong & relatively ductile
• Biocompatible
• Relatively cheap
• Reasonable corrosion resistance
Disadvantages
• Poor wear resistance
• Stress shielding of surrounding bone
& bone resorption
• High Youngs modulus

16. 2) TITANIUM
• Contains:
- Titanium (89%)
- Aluminium (6%)
- Vanadium
• Most commonly used is Titanium 64

17. Advantages
• Corrosion resistance
• Excellent biocompatibility
• Ductile
• Low Young’s modulus
• MR scan compatibility
• Osseointegration
Disadvantages
• Poor wear characteristics
• Systemic toxicity – vanadium
• Relatively expensive

18. 3) COBALT CHROME ALLOYS
• Contains primarily Cobalt (30-60%)
• Chromium is added to improve
corrosion resistance
• Usually used for bearing surfaces in
THR.

19. Advantages
• Excellent resistance to corrosion
• Excellent long term biocompatibility
• Very strong
Disadvantages
• Very high Young’s modulus
• Risk of stress shielding
• Expensive

20. B) CERAMICS
• Compounds of metallic elements
bound ionically or covalently with
non-metallic elements.
• Common ceramics are:
- Aluminium
- Silica
- Zirconia
- Hydroxyapatite

21. • Ceramics are refractory polycrystalline compounds
- usually inorganic
- highly inert
- hard & brittle
- high compressive strength
- generally good electric & thermal insulator.

23. 1) ALUMINA ( inert ceramic)
• Better wear resistant with stainless
steel
• Application :
-femoral head
-bone screw & plates
-porous coating for femoral stems
-knee prosthesis

24. 2) ZIRCONIA (inert ceramics)
• Obtain from zircon
• Application :
- femoral head
- artificial knee
- bone screw & plates.

25. 3) BIOGLASS (bioactive ceramics)
• Hard , non-porous material of
calcium , phosphorous & silicon
dioxide.
• Osteointegrative & osteoinductive
properties.
• It is not used in high load bearing
devices due to low tensile strength
& toughness.

26. 4) CALCIUM PHOSPHATES (biodegradable
ceramics)
• Uses :
- Repair material for damaged bone
- Void filling after resection of bone tumour
- Repair & fusion of vertebrae
- Repair of herniated disc

27. C) TISSUE ADHESIVE
• Properties:
-Moderately viscous (spread easily)
-Ability to degrade at a appropriate rate
-Biocompatibility
• Commonly used are
- Fibrin gel, Albumin & mucopolysaccharides.

28. D) CARBON MATERIAL & POLYMERS
1) CARBON FIBRES:
• Application-
- Total hip replacement
- Internal fixation for fractures
- Spine surgeries
• Disadvantages:
- Release of carbon debris in to the
surrounding medium.

29. 2)PMMA (polymethyl methylacrylate)
• Polymethyl methacrylate (PMMA), is
commonly known as bone cement, and is
widely used for implant fixation.
• The powder contains:
- PMMA copolymer
- Barium oxide(radio opacifier)
- Benzoyl peroxide ( catalyst)

30. • Stages of cement reaction:
- Dough time 2-3mints
- Working time 5-8mints
- Setting time 8-10mints
• Mainly used to fix prosthesis & also
be used as void fillers.
• Available as liquid & powder

31. Advantages
• Tough
• Ductile
• Resilient
• Resistant to wear
Disadvantages
• Susceptible to abrasion
• Thermoplastic
• Weaker than bone in tension

32. 3) UHMWPE (ultra high molecular
weight polyethylene)
-A polymer of ethylene with MW of 2-6
million.
-Metal on polyethylene has high success
rate in bearing surface in THR
- Used for acetabular cups in THR
prosthesis & tibial components in TKR.

33. 4) BIODEGRADABLE POLYMER
• It consist of polyglycolic, polylactic
acid, copolymers.
• Hardware removal is not necessary
thus reducing morbidity & cost.

34. GENERAL TISSUE-IMPLANT RESPONSES
• All implant material elicit some response from the host.
• The response occurs at tissue-implant interface
• Response depends upon-
- type of tissue
- mechanical load
- amount of motion
- composition of the implant
- age of patient

35. COMPLICATION
1) INFECTION
2) ASEPTIC LOOSENING
- Caused by osteolysis from body’s reaction to
wear debris
3) STRESS SHIELDING
- Implant prevents bone from being properly
loaded
3) CORROSION
- Reaction of the implant with its environment
resulting in its degradation to oxides.

36. 5) METAL HYPERSENSITIVITY
6) MANUFACTURING ERROR

37. RECENT ADVANCES
• Aim is to use material with mechanical properties that match those of the
bone.
• Modification to existing materials to minimize harmful effect ex; nickel free
metal alloys.
• Possibility of use of anti-cytokine in the prevention of osteolysis around
implants.
• Antibacterial implant.

38. • POROUS TANTALUM is also being
successfully used clinically in several
orthopaedic application.
• It has - high volumetric porosity
-low elastic modulus
- good frictional characteristics
• Ideal candidates for weight bearing
application such as total joint
arthroplasty.

39. THANK YOU