Biomaterial

1. DESIGN OF DURABLE IMPLANT FOR
TOTAL HIP ATHROPLASTY
Azeez Akeem Abiodun
Akpan Udom Mark
Cooper Lackay
Igwebuike Chidebere. Millicent
Wehleekema Siaplay
Biomaterial
April 2016

2. OUTLINE
• Introduction
• Introduction: Total Hip Replacement
• Anatomy of Hip
• Indication of Total Hip Replacement
• Reason for Hip replacement
• Types of Hip replacement surgery
• Comparism of wear rate
• Suggested solution
• Business plan
• Conclusion

3. INTRODUCTION
• In 1960, Late Sir John Charnley
has done pioneer work in all
aspect of THA, including the
concept of low frictional torque
arthroplasty, surgical alteration of
hip biomechanics, lubrication,
materials, design and clear air
operating room environment [1].
en.wikipedia.org/wiki/John_Charnley 3

4. INTRODUCTION :TOTAL HIP REPLACEMENT
• Total hip arthroplasty is an
operative procedure in which
the diseased and destroyed hip
joint is resected and replaced
with a new bearing surface [2].
• Patients with arthritis can now
look to THA with the object of
maintaining stability, while
relieving pain, increasing
mobility and correcting
deformity.
• MOST SIGNIFICANT BREAK
THROUGH OF THE 20Th
CENTURY
http://www.healthcentral.com/ 4

5. ANATOMY OF HIP JOINT
• The hip is one of the body's largest weight-bearing
joints.
• Consists of two main parts:
• a ball (femoral head) that fits into a rounded socket
(acetabulum) in your pelvis.
• Ligaments connect the ball to the socket and provide
stability to the joint
• The bone surfaces of your ball and socket have a
smooth durable cover of articular cartilage that
cushions the ends of the bones and enables them to
move easily.
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6. INDICATIONS FOR THA :
• The primary indication for THA is incapacitating PAIN. Pain in
the hip in the presence of destructive process as evidenced
by X-ray changes is an indication.
• THA is an option for nearly all patients with diseases of the
hip that cause chronic discomfort and significant functional
impairment.
• Patients with limitation of movement, leg length inequality
and limp but with little or no pain are not the candidates for
THR.
Note: All options of treatment must have been explored
before considering THA [3].
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7. REASONS FOR HIP REPLACEMENT
Most common reasons for total hip
replacement:
• Osteoarthritis 60 %
• Rheumatoid arthritis 7 %
• Fractures/dislocations11 %
• Aseptic bone necrosis 7 %
• Revision 6 %
• Other 9% [4]
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8. HIP REPLACEMENT COMPONENTS
Acetabular component - consists of
two components
• Cup - usually made of titanium
• Liner - can be plastic, metal or
ceramic
• Femoral components
Head
Neck
stem 8

9. CONVENTIONAL BEARINGS
• Osteolysis secondary to polytetrafluroethylene ( Teflon)
particulate debris has emerged as the most notable factor
endangering the long-term survivorship of total hip
replacements.
• alternative bearings have been advocated to diminish this
problem
• These are-
-Metal-on-Polyethylene
-Ceramic-on-Polyethylene
-metal-on-metal
-ceramic-on-ceramic [5]
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10. METAL ON POLYETHYLENE
• This consist of basically three parts:
• an ultra-high molecular weight polyethylene
cup that replaces the hip socket,
• a metal ball to replace the femoral head and
• a metal stem that is inserted into the shaft
of femur to add stability to the prosthesis.
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11. CERAMIC-ON-POLYETHYLENE
This consist of basically three parts:
• an ultra-high molecular weight polyethylene cup
that replaces the hip socket,
• a ceramic ball to replace the femoral head and
• a metal stem that is inserted into the shaft of femur
to add stability to the prosthesis.
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12. METAL-ON-METAL BEARINGS
• Metal-on-metal implants seem to be tolerant of high
impact loading, and mechanical failure has not been
reported.
• wear rates less than 10 mm/y for modern metal-on-
metal articulations
• But there remains major concern regarding the
production of cobalt and chromium metallic debris,
and its elimination from the body.
• metal-on-metal (MOM) bearings have a ‘suction-fit’
less chance of dislocation
(J Bone Joint Surg [Br] 2003;85-B:650-4)
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13. CERAMIC-ON-CERAMIC BEARINGS
• Alumina ceramic has many properties that make it desirable as a
bearing surface in hip arthroplasty
• high density- surface finish smoother than metal implants
• The hydrophilic nature- ceramic promotes lubrication
• Ceramic is harder than metal and more resistant to scratching from
third-body wear particles.
• The linear wear rate of alumina-on-alumina has been shown to be
4000 times less than cobalt-chrome alloy–on–polyethylene.
• Ceramic-on-ceramic arthroplasties may be more sensitive to
implant malposition than other bearings. (J Bone Joint Surg [Br]
2003;85-B:650-4
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14. SURGICAL OPERATION FOR THR
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15. COMPARISM OF WEAR RATE OF DIFFERENT
COMBINATIONS OF THR
15(http://exactech.co.jp/uk/products/hip)

16. LATEST INNOVATIONS IN DESIGNING THA
• Ceramic-on-UHMWPE
• Ceramic-on-HXLPE
http://quotesgram.com/hip-replacement-
quotes 16

17. LATEST INNOVATIONS IN DESIGNING OF FEMORAL
HEAD
17
Bernard M et al, 2001

18. REINFORCING SYSTEMS
The main reinforcing materials that are biocompatible are
• Carbon fiber
• Glass fibers
• Polymer fiber
• Ceramics fibers
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19. PROPOSED SOLUTION
We propose that using Alumina Matrix Composite (AMC) will address
the brittle nature of alumina made femoral head.
• Calcium phosphate belong to group of bioactive synthetic material
 Hydroxyapatite (Non-resorbable)
 Tricalcium phosphate (resorbable)
• Using calcium phosphate as second phase will toughen the femoral
head by arresting crack through crack bridging.
• Research needs to be carried out to determine the best volume
fraction of hydroxyapatite particles that we provide the desired
fracture toughness.
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20. MECHANICAL PROPERTIES OF AMC
Source: Gulio et al, 2013
Source: Jabr.S et al, 2013
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21. RULE OF MIXTURE FOR COMPOSITE
By varying the volume fractions of the matrix and particles, we can determine
the best Young’s modulus of the composite that will resist crack propagation.
http://slideplayer.com/slide/3091954/ 21

22. RULE OF MIXTURE CONT’D
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23. BUSINESS PLAN
From data we got from CIA world fact book (www.cia.gov), Nigeria demographics
• 15-24 years: 19.3% (male 17,486,117/female 16,732,533)
• 25-54 years: 30.5% (male 27,67,644/female 3,571,301)
• 65 years and over: 3.1% (male 2,621,845/female 2,861,826) (2014 est.)
Reason for THA :
• Osteoarthritis 60 %
• Fractures/dislocations 11 %
Average cost of Total Hip Arthroplasty implant surgery:
Ceramic-on-ceramic $7,500
Metal-on-metal $5,500
With our proposed material, we will reduce the number times of revision and as well cost
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24. CONCLUSION
• We did literature review on various combinations of THA implant
• Our research shows that ceramic-on-ceramic THA has the lowest wear rate and
therefore has the potential of having greatest survivorship of all the
combinations.
• Disadvantages are:
Brittleness
High cost
In lieu of this, we propose
Ceramic-on-HXLPE (for efficiency and to reduce cost )
NanoAlumina matrix composite (AMC) to drastically reduce crack propagation and
toughening of the femoral head.
Thereby reducing cost and number of revision surgery.
http://www.jortho.org/
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25. REFERENCES
1. en.wikipedia.org/wiki/John_Charnley
2. http://www.uptodate.com/contents/total-hip-replacement-arthroplasty-
beyond-the-basics retrieved on 10th, April 2016.
3.http://www.niams.nih.gov/Health_Info/Hip_Replacement/hip_replacement_ff.
asp retrieved on 10th , April 2016
4. Monti khato et al:An analysis of the risk of hip dislocation with
contemporary total joint registry.
5. Brummitt K, Hardaker CS, McCullagh PJ, Drabu KJ, Smith RA. Effect
of counterface material on the characteristics of retrieved titanium
alloy total hip replacements. J Eng Med 1996;210(3): 191–5
6.Jabr.S, A. Madfa et al: Review article on Application of calcium
phosphate materials in dentistry.
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