The word tribology was first used in a landmark report by Jost as referenced by Bhushan. The etymology has to be referred to the Greek term tribos meaning rubbing, so that literally this would signify “the science of rubbing”. The equivalent ordinary English language is “friction and wear”. The Oxford dictionary defines tribology as the science and technology of interacting surfaces in relative motion and of related subjects and practices. Tribology as a science succeeds in applying effective analysis to solve problems of great economic significance for social communities, that is, reliability, maintenance, and wear of technical equipment, ranging from spacecraft to medical devices. Interest in the essential parts of tribology is older than recorded history. It is well-known that drills made during the Palaeolithic period for drilling holes or producing fire were fitted with bearings made from antlers or bones, and potters’ wheels or stones for grinding cereals, had preferable requirement for some form of bearings.
This science includes different disciplines such as friction, lubrication theory and technique, study and use of lubricants, microscopic and macroscopic theories of wear, study and use of wear resistant materials.
In particular, friction comes into play in the production processes and influence forces, powers, in play, consumption and quality of the parts. The wear changing surfaces and geometries of moulds and tools determining the consistency and quality of the geometries produced. Finally, the lubrication in the production processes is essential both in the manufacturing operations and in the operation of the machines.

Hip simulator

In the orthopaedics field, wear of the prosthesis is a significant clinical problem that involves, today, too many patients.
In total hip/knee replacement, improving the quality and outcomes in patients requires careful evaluation of the clinical data available, in order to fully assess the existing strengths and weaknesses. Holders of arthroplasty have become and continue to become younger. Each year runs over a million total hip and knee arthroplasty. This implies that the implants and materials used must be highly qualitative, in particular as regards resistance to wear. The total joint arthroplasty should be based on clinical trials in order to obtain the best possible results.

Knee simulator

In this regard, the research group of tribology conducts basic research and industrial use of simulators wear. In this way they are used protocols that allow to replicate/simulate particularly extreme conditions, thus establishing the limits of performance for the material.
There are several reports on the wear rates of different combinations: ceramic/polyethylene vs. metal/polyethylene. The cross-linked polyethylene achieved good results in both combinations. Undoubtedly, the surface roughness of a material is an indication of a good wear behaviour or not. The roughness is less for the ceramic-on-ceramic bearing.
The section of Tribology runs wear tests on medical devices for both hip or knee such as: ceramic-on-ceramic; metal-on-metal; metal-on-polyethylene; ceramic-on-polyethylene.
Other tests/set-up on other medical devices (ankle, shoulder, etc.) could be negotiated in order to define a protocol.
The group of Tribology has participated as a partner in several national and European projects. It should be emphasized, in particular, the participation in:

  • BIOKER, GROWTH 2000, Contract nº G5RD-2000-00483.
  • NANOKER, INTEGRATED PROJECT, Contract nº FP6-515784-2.
  • COST ACTION 533 (2006-2010).
  • COST ACTION NEWGEN MP1201 (2013-2017).
  • TEMPUS project WIMB, Contract no. 543898-TEMPUS-1-2013-1-ES-TEMPUS-JPHES (2013-2016).

Selected publications of the tribology group:

  • Santina Battaglia & Paola Taddei & Silvia Tozzi & Alessandra Sudanese & Saverio Affatato. Toward the interpretation of the combined effect of size and body weight on the tribological performance of total knee prostheses. International Orthopaedics (SICOT).
  • Laura Grillini, Saverio Affatato. How to measure wear following total hip arthroplasty. Hip Int 2013; 23 (3): 233-242.
  • Saverio Affatato, Laura Grillini, Santina Battaglia, Paola Taddei, Enrico Modena, Alessandra Sudanese. Does knee implant size affect wear variability? Tribology International 66 (2013) 174–181.
  • Saverio Affatato, EnricoModena, SimoneCarmignato, PaolaTaddei. The use of Raman spectroscopy in the analysis of UHMWPE uni-condylar bearing systems after run on a force and displacement control knee simulators. Wear 297 (2013) 781–790.
  • Saverio Affatato, Enrico Modena, Simone Carmignato, Thomas M. Grupp, Paola Taddei. Quantification of Wear Rates and Plastic Deformation on Mobile Unicompartmental UHMWPE Tibial Knee Inserts. Tribol Lett (2013) 52:57–65.
  • S. Affatato,
F. Traina,
M. De Fine,
S. Carmignato, A. Toni. Alumina-on-alumina hip implants A WEAR STUDY OF RETRIEVED COMPONENTS.  J Bone Joint Surg Br 2012;94-B:37–42.
  • S. Affatato, E. Modena, A. Toni, P. Taddei. Retrieval analysis of three generations of Bioloxs femoral heads: Spectroscopic and SEM characterisation. Journal of the mechanical behavior of biomedical materials 13 (2012) 118–128.
  • Saverio Affatato a, Paola Taddei, Simone Carmignato, Enrico Modena, Aldo Toni. Severe damage of alumina-on-alumina hip implants: Wear assessments at a microscopic level. Journal of the European Ceramic Society 32 (2012) 3647–3657.
  • Saverio Affatato, Pierangiola Bracco, Luigi Costa, Tomaso Villa, Virginio Quaglini, Aldo Toni    In vitro wear performance of standard, crosslinked, and vitamin-E-blended UHMWPE. J Biomed Mater Res Part A 2012:100(3):554–560.
  • S. Affatato, F. Traina, M. De Fine, S. Carmignato, A. Toni. Alumina-on-alumina hip implants - A wear study of retrieved components. J Bone Joint Surg Br 2012;94-B:37–42.
Content updated 25/06/2014 - 12:05
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