Thesis (Ph.D.) University of Alaska Fairbanks, 2004Approximately 600,000 total joint replacement surgeries are performed each year in the
United States. Current artificial joint implants are mainly metal-on-plastic. The synthetic
biomaterials undergo degradation through fatigue and corrosive wear from load-bearing and the
aqueous ionic environment of the human body. Deposits o f inorganic salts can scratch weight-bearing
surfaces, making artificial joints stiff and awkward. The excessive wear debris from
polyethylene leads to osteolysis and potential loosening of the prosthesis. The lifetime for well-designed
artificial joints is at most 10 to 15 years. A patient can usually have two total joint
replacements during her/his lifetime. Durability is limited by the body’s reaction to wear debris of
the artificial joints. Wear of the artificial joints should be reduced.
A focus of this thesis is the tribological performance of bearing materials for Total
Replacement Artificial Joints (TRAJ). An additional focus is the scaffolds for cell growth from
both a tissue engineering and tribological perspective. The tribological properties of materials
including Diam ond-like Carbon (DLC) coated materials were tested for TRAJ implants. The
DLC coatings are chemically inert, impervious to acid and saline media, and are mechanically
hard. Carbon-based materials are highly biocompatible. A new alternative to total joints
implantation is tissue engineering. Tissue engineering is the replacement of living tissue with
tissue that is designed and constructed to meet the needs of the individual patient. Cells were
cultured onto the artificial materials, including metals, ceramics, and polymers, and the frictional
properties of these materials were investigated to develop a synthetic alternative to orthopedic
transplants.
Results showed that DLC coated materials had low friction and wear, which are desirable
tribological properties for artificial joint material. Cells grew on some of the artificial matrix
materials, depending on the surface chemistry, wettability, morphology, microstructure etc. The
dry, lubricated, and cell culture friction tests showed that bovine serum albumin solution and
culture media performed as lubricants. Frictional properties varied. Glass and TR-2 (PET,
polyethylene terephthalate) showed good cell culture results and low friction. Both are suitable
materials, both as artificial joint implant coatings and as substrates for preparing total joint
implants via tissue engineering.Signature Page -- Title page -- Abstract -- Table of Contents -- List of Figures -- List of Tables xiii
List of Appendices -- Acknowledgements -- Chapter 1: Introduction -- Chapter 2: Experimental: materials, equipment, and methods -- Chapter 3: Tribological performance of alternative bearing materials for TRAJ: results and discussion -- Chapter 3: Tribological performance of materials as scaffolds for cell growth:
Results and discussion of cell culture - a tissue engineering approach -- Chapter 4: Tribological performance of materials as scaffolds for cell growth:
Results and discussion of cell culture - a tissue engineering approach -- Chapter 5: Tribological performance of materials as scaffolds for cell growth:
Results and discussion of tribological tests -- Chapter 6: Conclusions and future work -- Reference -- Appendice
