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‘The low-down’
• The replacement- ‘The enemy’• The problem with Hip prosthesis• 3 Possible ways to improve the Hip prosthesis• Summary
Stem Cells
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The replacement
Stem cells therapy used in a patient.
Spire hospital, Southampton.
• The patient’s own bone marrow to harvest stem cells
• Stem cells grown in lab and injected into Hip with platelet rich plasma
• Problems: Expensive, storage, availability and regulatory issues.
Problems with Hip Prosthesis
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Mechanically-assisted crevice corrosionMicro motion + crevice
corrosion between head and stem
High Wear rates
Usually between Head and Cup
Capsule formation
Host reaction to bacterial infection of implant.
Infection liability
Can be infected very easily during surgery.
Hard to solve all at once
MPC Polymer
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2-methacryloyloxyethyl phosphorylchlorine (MPC).
MPC Polymer
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Solution 1
Fig1. Long‐term testing of the artificial
hip joint bearing surface grafted with MPC
About MPC
• Resemble phospholipid bilayer through polar groups• Can radically decrease wear between head and cup• Can prevent bacterial attachment due to
‘superhydrophilicity’/ inhibiton of cell adhesion• Does not cause inflammatory response when in
contact with macrophages
“Discovered in 1978 but could only produce 1mg per year!”
Fig1,2. Moro T, Takatori Y, Kyomoto M, Ishihara K, Hashimoto M, Ito H et al. Long-term hip simulator testing of the artificial hip joint bearing surface grafted with biocompatible phospholipid polymer. J Orthop Res. 2013;32(3):369-376.
Fig2. Showing MPC liner structure and
acetabular cup with MPC liner
PEEK FIBRESSelf Reinforced CompositeSO
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PEEK FIBRES
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Solution 2
Fig3. Difference in current as load increases,
in hip implants with/without PEEK Fibres
About PEEK Fibers
• Placed in between the taper region of the implant• Usually two fibres, which spread out to cover the
neck of the implant• Forms a tighter connection between head and neck• Results in soft, non-conducting layer, preventing the
loss of the oxide film.
“Compulsory with Metal implants in the US since 2014!”
Fig3. Google Books, (2015). Patent US20140197571 - Prevention of fretting crevice corrosion of modular taper interfaces in orthopedic implants. [online] Available at: http://www.google.com/patents/US20140197571 [Accessed 15 Feb. 2015].
CAPE LOADED PMMABone CementSO
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CAPE LOADED PMMA
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Solution 3
Fig4. Showing CAPE and GM
dispersion within a PMMA network
About CAPE loaded PMMA
• Active component of bee propolis ( used to fill holes in bee hives)
• Has antimicrobial, anti-inflammatory, antioxidant and anti-cancer effects
• Better compressive strength than GM-PMMA. Similar to native PMMA
• Higher packing density caused by reinforced chemical bonding between the PMMA and CAPE
• More controlled and sustained microbial release
Fig3: Lee H, Chang J. Antimicrobial spine-bone cement with caffeic acid phenethyl ester for controlled release formulation and in vivo biological assessments. Med Chem Commun. 2015;6(2):327-333.
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The Stem cell revolution is taking over from the Hip prosthesis
.
There are numerous problems with the Hip prosthesis
MACC, Wear, Capsulation and infection are the main ones
MPC can decrease wear rate significantly
PEEK can reduce MACC between the head and stem of a metal implant
CAPE loaded PMMA is a good replacement to GM-PMMA.
KEY TAKEAWAYSThe Important Stuff
That’s all. Thank you! Any Questions?
References
• Spirehealthcare.com. Stem cell technique prevents hip replacements [Internet]. 2015 [cited 26 February
2015]. Available from:
http://www.spirehealthcare.com/southampton/news/stem-cells-technique-to-prevent-hip-replacements/
• Plancher Orthopedics. Are Stem Cells the Future of Hip Replacement? - Plancher Orthopedics [Internet]. 2014
[cited 25 February 2015]. Available from: http://plancherortho.com/stem-cells-future-hip-replacement/
• J Centeno C. Efficacy and Safety of Bone Marrow Concentrate for Osteoarthritis of the Hip; Treatment Registry
Results for 196 Patients. Journal of Stem Cell Research & Therapy. 2014;04(10). • Moro T, Kawaguchi H, Ishihara K, Kyomoto M, Karita T, Ito H et al. Wear resistance of artificial hip joints with
poly(2-methacryloyloxyethyl phosphorylcholine) grafted polyethylene: Comparisons with the effect of polyethylene cross-linking and ceramic femoral heads. Biomaterials. 2009;30(16):2995-3001.
• Moro T, Takatori Y, Kyomoto M, Ishihara K, Hashimoto M, Ito H et al. Long-term hip simulator testing of the artificial hip joint bearing surface grafted with biocompatible phospholipid polymer. J Orthop Res. 2013;32(3):369-376.
• Google Books, (2015). Patent US20140197571 - Prevention of fretting crevice corrosion of modular taper
interfaces in orthopedic implants. [online] Available at: http://www.google.com/patents/US20140197571
[Accessed 15 Feb. 2015].
• Nakahara I, Takao M, Bandoh S, Sugano N. Fixation strength of taper connection at head–neck junction in
retrieved carbon fiber-reinforced PEEK hip stems. Journal of Artificial Organs. 2014;17(4):358-363.
• Rsc.org. From beehive to bone cement | Chemistry World [Internet]. 2015 [cited 25 February 2015]. Available from: http://www.rsc.org/chemistryworld/2014/11/bone-cement
• Lee H, Chang J. Antimicrobial spine-bone cement with caffeic acid phenethyl ester for controlled release formulation and in vivo biological assessments. Med Chem Commun. 2015;6(2):327-333.