A considerable number of total-joint replacement devices used in orthopedic medicine involve articulation between a metallic alloy and ultra-high molecular weight polyethylene (UHMWPE). Though this polymer has excellent wear resistance, the wear particulate produced leads to the limited lifetime of the devices – osteolytic bone loss. Crosslinking has been shown to reduce the wear rate of UHMWPE, but can cause a reduction in various mechanical properties such as impact toughness. This study presents two alternate approaches to improving the wear performance of UHMWPE in orthopedic applications Previous work has shown that UHMWPE-based composites have wear resistance comparable to the irradiation-crosslinked polymer. Zirconium has been shown to have excellent corrosion resistance and biocompatibility, and the authors have used the material as reinforcing filler in UHMWPE with promising results. Compression-molded UHMWPE composites with up to 20 weight percent (wt%) of micro-sized zirconium particles were investigated with regards to wear behavior and impact toughness. These composites showed a significant reduction in wear compared to unfilled polymer while still maintaining impact toughness. These results reinforce the paradigm of using polymer composites for orthopedic applications and may provide a viable alternative to the property tradeoffs encountered with irradiation crosslinking. Apart from UHMWPE, novel materials including hydrogels and bio-derived polymers show great potential in orthopedics, but such materials require the development of innovative fixation techniques [1-3]. The development of controlled porous UHMWPE morphologies offers the opportunity to utilize and expand these developing technologies. Interconnected porous structures were prepared by dry mechanical mixing of NaCl particles and UHMWPE powders followed by compression molding. Samples were soaked in water to remove the embedded salt, leaving a porous UHMWPE structure. Computational simulations of porogen distribution and leaching predicted leaching to be 95% effective when initial salt concentrations were 60wt% and higher, which was found to match very well with the experimental data. It was found that varying the concentration and particle size of the porogen can tailor the final pore morphology to a specific application, while DMA results showed that storage and loss moduli depend greatly on porosity, but not on pore size. Finally, porous UHMWPE scaffolds were successfully impregnated with gelatin, confirming the compatibility of UHMWPE with hydrogel-based fillers.

This thesis research investigates the adhesion mechanisms of protein molecules to surfaces of biomaterials. New understanding in such adhesion mechanisms will lead to materials design and surface engineering in order to extend the lifespan of implants. The present research evaluates and analyzes the adhesive strength of proteins on pure High Density Polyethylene (HDPE), Single Wall Carbon Nanotube (SWCNT) enhanced HDPE composites, Ti-C:H coating and Ti6Al4V alloys (grade 2). The adhesive strength was studied through fluid shear stress and the interactions between the fluid and material surfaces. The adhesive strength of protein molecules was measured through the critical shear strength that resulted through the fluid shear stress. The effects of surface and material properties, such as roughness, topography, contact angle, surface conductivity, and concentration of carbon nanotubes on adhesion were analyzed. Research results showed that the surface roughness dominated the adhesion. Protein was sensitive to micro-scale surface roughness and especially favored the nano-porous surface feature. Results indicated that the unpurified SWCNTs influenced crystallization of HDPE and resulted in a nano-porous structure, which enhanced the adhesion of the protein onto a surface. Titanium hydrocarbon coating on silicon substrate also had a porous topography which enhanced its adhesion with protein, making it superior to Ti6Al4V.

隨著全球人口結構高齡化和醫療技術的日新月異，使得全球醫療器材市場，正以前所未有的速度，快速地蓬勃發展，預估2006年全球醫療器材市場的總值約為1,643.57億美元，相對於2006年我國醫療器材產業的營業額新台幣690億元，我國目前大概只佔全球醫療器材市場總值的1.4%，相較於半導體、以及電子業稱霸國際，全球醫療器材市場，不啻是我國廠商的一片藍海! 2004年全球骨科市場的價值達190億美元，預期未來十年的年平均成長率將高達10~13%，聯合骨科在人工關節的設計與製造，具有亞洲第一的水準，非常具有競爭優勢，然而，由於歐美知名品牌的公司規模及在中國人工關節市場先驅者的地位，聯合骨科如何在激烈的競爭環境中脫穎而出，考驗著聯合骨科經理人的智慧；目前，聯合骨科在台灣及大陸，分別擁有約20% 以及10% 的市場佔有率，並在西安與新竹建立生產基地。 透過實際參與中國人工關節市場操作的台灣及大陸的聯合骨科經理人、競爭廠商經理人、以及學術界的專家的角度，利用策略行銷4C成本理論，分析聯合骨科在中國人工關節市場的發展現況的優缺點與可能的成因之後，本研究建議聯合骨科在運用有限資源的有效性及時效性的考量之下，可以考慮優先解決買者的外顯單位效益成本以及買者的專屬陷入成本，進而取得市場上的優勢，除此之外，如果他們能夠持續地提升技術層面的優勢之外，更進一步的創造行銷與服務方面的效能，必能在中國的人工關節市場上，取得優勢，創造出更亮麗的成績；深耕中國、佈局世界，以期與世界級的品牌大廠，能夠在全球的人工關節市場競爭上，有更卓越的表現！ / Along with global aging population and rapid advancement of medical technology, global medical devices market is increasing at the fastest speed ever and is reaching US$ 164B in 2006. 2006 Taiwan medical devices market is US$ 2.3B which is only 1.4% of overall global medical devices market. Comparing with dominant positions of Taiwan semiconducting and electronic industries, global medical devices market is a great “Blue Ocean” opportunity! Global orthopedic market will reach US$ 19B in 2004 and is expected to grow at 10-13% annually for the coming 10 years. United Orthopedic Corporation （UOC） is very competitive and is in a leading position in orthopedic joint design and manufacturing in Asia. Due to relative large company size and market pioneer position of well-known US & European brands in China, management team of UOC is facing a tremendous challenge to win this game；So far, UOC is holding 20% and 10% of market share in Taiwan and China, respectively. UOC has set-up manufacturing bases in both Xian and Hsin-Chu. After consolidating individual assessment of UOC management team, competitors’ management team as well as experts from academic society who are personally involving in orthopedic joint market in China and applying the strategic marketing analysis of 4C theory, we have concluded the strength/weakness and their possible causes of UOC current market status in China. Based on our findings, we suggest UOC could consider utilize its limited resources effectively and efficiently, as priorities, to build up its competitiveness on Cost/Utility ratio and Asset Specificity. If UOC can create effectiveness on both marketing and service furthermore, it can achieve competitive advantage and better performance in China orthopedic joint market；Establishing a strong foundation in China and structuring its market position in the world. UOC will be able to tackle face-to-face competition with world-class orthopedic companies in global market!