Nano Materials and Structures for Superior Implants (Nanoplants)

Various RCUK funded projects at Loughborough University over the years have delivered significant foreground intellectual property and technology know-how related to the fabrication of nanostructured materials with outstanding properties, surpassing some of the commercial counterparts, relevant to the energy, electronic security and in particular healthcare sectors. Specifically it has been demonstrated that the hydrothermal ageing (HTA) resistance of zirconia based ceramics can be enhanced significantly by retaining a nano grain size below 180 nm even at low density components. This is highly relevant to the ~$5B hip replacement market where concerns about the toxicity / wear debris in metal and polymer components renders all-ceramic solutions increasingly attractive. HTA degradation (the unwanted conversion of tetragonal zirconia to a weaker monoclinic form in an aqueous environment) is the Achilles-heel for the use of zirconia ceramics in biomedical sector and was the reason behind the well-publicised failure of zirconia hip replacements around 2000. Thus, when HTA is countered, new opportunities open up. The proposed technology (involving novel nano-suspension control, granulation and then microwave assisted hybrid heating as well as flash sintering regimes; zirconia toughened alumina and zirconia ceramics will be considered) aims to deliver very small zirconia grain sizes that will both assist current compliance (e.g. ISO 13356, ISO 633-3) and open up novel all-ceramic hip replacements via multi-fold enhancement in HTA-resistance of porous and dense graded zirconia based structures. The methodology will be applicable to ceramic-metal graded implant structures also with suitable modifications. The retention of nano-size throughout all stages of ceramic component production is critical to delivering the target end properties that will assist the health and quality of life in a growing ageing population. This will be achieved via the development of implant structures (applicable for hip/knee prosthesis, finger joints and jaw & skull repairs) that deliver improved mobility over a longer time period thus reducing reliance on repeat surgery and in some cases confinement to use of wheelchair.

2008 data estimates that the global hip replacement market is ~$5.6B. Knees and Spines account for a further $6.7B and 8.1B respectively and adding in trauma, extremity, sports segments create a total market of ~$31B. Between 1995 and 2008, it enjoyed a 10-15% per annum growth rate. Despite the recent economic down-turn, growth rates remain at >6%.The business opportunity addressed by this project is to create hip (and subsequently other bone) replacement components featuring a superior performance nano-ZTA or nano-zirconia and thus make in-roads firstly into the $5.6B world-wide hip replacement market and subsequently within the ~$31B world-wide orthopaedics market. Based on Hip and Knee market data, Europe has a 30 % share of the market, whilst the USA has a 50% share; it should also be noted that use of ceramics is increasing with an average 20% of implants using ceramics predicted for 2013 and above. Interestingly, Europe (up to 50% utilisation) is embracing ceramics more than the US (5% utilisation) meaning significant future export opportunities. A closer inspection of the market data also suggests that the USA, Europe and Japan account for 80% of the market, even though from a population perspective, these regions make up just 20% of the 6.7B world population. This illustrates the huge global growth potential in this area: As the standard of living in India, China, other countries rises, so will the demand for joint replacement operations.
The project partner foresees at least a doubling of their ~1M current hip markets by 2017. LU sees significant IP generation and licensing opportunities. MAM supplies components that are used in the final implant (femoral head, acetabular cup) assemblies ultimately implanted by surgeons. Companies supplying final assemblies include the following big companies (turnovers adjacent): Stryker $5.75B; J&J $4.93B; Zimmer $3.99B; S&N $2.93B. Though not part of this consortium, such companies will have a key role to play in commercialising any nano-ceramic component emerging from the project. From an environmental aspect, nano-zirconia and eco-friendly microwave and flash sintering offers the potential for lower sintering temperatures (~300-600C reduction in peak firing temperatures respectively). This will lead to significant energy savings and less CO2 emissions.
Currently 61% of joint replacements are for the 65+ age group and 36% are at 45-64, figures in both age categories are set to rise as people live longer and younger people are increasingly willing to pay for operations that allow them to enjoy sports that place a strain on joints for longer. Being able to offer patients just one hip replacement during their life can have a massive impact on quality of life and hospital costs. In 2008 there were nearly 74,000 hip replacements (50,500 NHS) in the UK. A mean stay of a week in hospital and a "cost per day in hospital" of £225 leads to £80M/year NHS cost. It can be seen that 1 instead of 2 hip replacements will bring significant benefits. The goal of achieving implant surface porosity opens up the option of having slow release anti-bacterial agents that could prevent the 2-3% rate of infections associated with hip and knee replacements annually, that further costs £5.2M to NHS. Alternatively, if impregnated with mechanically enhanced hydroxyapatite, the porous surface could provide anchorage points for live bone (see Case for Support). This could reduce the recuperation time and pressure on hospital beds.
Sale of products and a reduction in raw material consumption and recycling, or increased market share through sales of superior products that may also be more durable, will help assisting in waste minimisation. Production costs can also be lowered, raising UK competitiveness and encouraging growth in UK advanced ceramics production via development of innovative and sustainable high value products, something identified as critical in the face of low cost competition.