Originally Published EMDM May/June 2005
Experts predict steady growth for this industry segment as advances in
materials and surgical procedures improve patient outcomes.
Did you know that we are in the fifth year of the Bone and Joint Decade? Neither did I. The multidisciplinary global campaign was formally launched by the World Health Organization in Geneva in January 2000. The initiative is intended to raise awareness of the suffering and costs associated with musculoskeletal disorders.
Let’s be charitable and say that the jury is still out on how effective the campaign has been. There is no denying, however, that demand for orthopaedic products will maintain steady growth for the foreseeable future. Patients with weary joints won’t quietly resign themselves to a diminished quality of life, and thanks to advances in biomaterials, manufacturing processes, and surgical procedures, they won’t have to.
In the developed world, bone and joint diseases account for half of all chronic conditions among people older than 50. Given the rapidly growing number of people in this age group, industry observers note that demographics alone will drive growth in the orthopaedics sector.
The European orthopaedic implants and trauma products market is forecast to exceed d 2.3 billion by 2008, according to a report published by Medtech Insight, a division of Windhover Information (London, UK).
Hip- and, increasingly, knee-joint replacements represent the largest market segment. In 2003, says a Frost & Sullivan report, the total value of the hip and knee replacement market was estimated at more than d1 billion. Going forward, the consultancy projects growth at a compound annual rate of 4.7%. One of the economic drivers identified by this and other reports is an increasing number of younger sufferers opting for joint replacement surgery.
Improving Patient Outcomes
Innovative procedures that have improved patient outcomes have played a considerable role in swaying younger patients to consider hip and knee implants. EUCOMED cites the remarkable results of minimally invasive surgical techniques. A total knee replacement operation performed in the UK in 2003 slashed hospitalization time to less than two days. The NexGen MIS Mini-Incision knee procedure developed by Zimmer (Warsaw, IN, USA) enabled the patient to leave the hospital after 45 hours instead of the standard eight days.
Advances in materials such as metal-on-metal and ceramic-on-ceramic components and the use of modified polyethylene have contributed to the development of more-durable implants. Innovations abound. For example, Metoxit AG (Thayngen, Switzerland) recently announced the development of an alumina-toughened zirconia that can withstand loads that are four times greater than conventional Al2O3 implants.
The firm reports that simulated testing shows that the load-bearing capacity of alumina ball heads in hip implants decreases by 90% when there is contamination between the metal and ceramic surfaces. This may place the fracture load under 10 kN. By contrast, the fracture load of the firm’s ATZ Bio-Hip composite material, which is composed of 80% tetragonal zirconia polycrystals and 20% alumina material, was almost 40 kN. To learn more about this product, see the article titled “Researchers Expand Biomaterials-Related Body of Knowledge” in the September 2004 issue of EMDM, or go to www.devicelink.com/emdm/archive/04/09/001.html.
The Virtues of
Virtual Product Development
Biomedical devices require physical testing before certification, release for clinical trials, and ultimate use by doctors and patients. “Physical tests are time-consuming, cost-prohibitive, and often incapable of providing a complete understanding of a product’s performance . . . in real-life applications,” says Leslie Rickey, industry manager, medical device market, at MSC.Software Corp. (Santa Ana, CA, USA). Virtual product development (VPD) processes and tools, including finite-element analysis simulation software, can speed the process, she adds.
VPD technologies are a subset of product life cycle management techniques that includes all technologies related to product design and engineering. VPD technologies rely on computer simulation to predict product performance. With VPD, an integrated combination of simulation software technology and traditional physical testing is used at each phase of the product design process to simulate and correlate product performance. “Using virtual prototypes to detect problems or performance issues early in the product development process enables problems to be correlated quickly,” explains Rickey. “The physical test process then becomes a validation phase, thereby reducing time to market.”
No two bones share identical geometry and material properties, continues Rickey. The cost of test equipment, as well as the time necessary to conduct experiments such as heavy fatigue testing of joint replacement products, make physical testing both an economic and a time issue. “VPD can help balance risks associated with new product development by providing the ability to simulate the reaction of complex materials to stress, temperature, fatigue, and other strain or loading scenarios,” says Rickey. This insight provides engineers with a better understanding of device behaviour and interaction, she adds, allowing them to make better decisions. “For example, an engineer can determine whether a new material or concept is feasible and what, if anything, should be redesigned.”
A finite-element analysis program developed by MSC.Software was used to examine implant failure modes at the Centre for Biomedical Engineering in London. The study could have been done by means of physical testing, noted researcher Sunita Ahir, PhD. But that would have required substantially more tests to cover the full range of design variations. The study is described in detail in the Engineering Insight column published in the November/December 2004 issue of EMDM,
which can be accessed via the Internet at www.devicelink.com/ emdm/archive/04/11/015.html.
On the following pages, EMDM profiles a sampling of suppliers of testing software, biocompatible materials, and metal fabrication and coating services relevant to the orthopaedics industry. Many more can be sourced on-line in the European Suppliers Directory at www.devicelink.com.
Wales Medical Engineering Institute Partners with Industry to Further Orthopaedics Research
Makers of orthopaedic products have a new resource at Cardiff University in the United Kingdom. The Institute of Medical Engineering and Medical Physics at the School of Engineering was launched in February to provide a framework for multidisciplinary research geared to applying engineering principles to healthcare.
The institute is currently working with industrial partners in the design, development, and testing of orthopaedic implants. Particular emphasis is placed on the development of numerical models to analyze human joint movement and the detection of deep vein thrombosis using novel imaging techniques. The institute has access to its own MRI scanner and a range of ultrasound equipment. A fully equipped gait-analysis laboratory incorporating high-speed cameras can be used to analyze knee function.
For more information about the institute’s activities, contact codirector and professor Len Nokes, Cardiff School of Engineering, by phone, at +44 29 20875907, or e-mail, email@example.com.
Swiss Watchmaking Supplier Turns to Medical Technology
A company with more than 100 years of experience making turned parts for the Swiss watch industry is increasingly making time for medical device OEMs. It routinely fabricates parts from materials such as titanium and stainless steel for use in orthopaedic, cardiology, dental, and hearing-aid products.
Boasting 120 machines, Lauener + Cie. S.A. (Boudry, Switzerland) can deep drill parts in dimensions from 0.60 mm diam, profile and tap medical threads, broach a variety of shapes, and mill complex geometries. A range of surface-treatment options are also available including passivation, anodization, laser engraving, heat treatment, and polishing.
The company is certified to ISO 9001:2000, ISO 13485, and ISO 14001. Strict quality controls are applied at each stage of the manufacturing process to ensure compliance with customer specifications.
Virtual Product Development Tools Designed for Orthopaedic Device Manufacturers
Custom software modules and professional services packages have been developed for use by the orthopaedics sector. MSC.Software Biomedical Packages from MSC.Software GmbH (München) provide engineers with full access to the firm’s SimOffice product portfolio of relevance to the device industry. The set of design, biomechanics, and finite-element analysis (FEA) software provides engineers with the tools they need to “design and test new devices as quickly and efficiently as possible,” says CEO and chairman Bill Weyand.
Designers of orthopaedic products can use various tools to perform functional simulations of devices using musculoskeletal models. Virtual loads, boundary conditions, and forces resulting from functional performance simulations can be incorporated into integrated evaluations of stress and strain, and durability assessments.
This focused approach to device development and virtual testing offers several benefits, the company says. Specifically, it helps to reduce risk and accelerate innovation,regulatory product approval, and time to market.
Thermoformed Sheet and Foam Packaging Protects Implants
By combining thermoformed sheet plastics with foam inserts, a simple tray is transformed into a protective cushion package. The system safeguards the product from shock and vibration throughout its distribution cycle without impinging on sterilizability.
The package was developed by UFP Technologies Inc. (Georgetown, MA, USA), which manufactures particulate-free packaging for hip- and knee-joint replacements, spinal disc spacers, bone fixators, and related implants.
The use of clear thermoformed plastics to create the outer shell facilitates item identification and retrieval. Combining such shells with compression-moulded foam retainers enables a single tray design to accommodate different products. The use of a standard base tray and modified foam inserts allows existing packaging to be adapted to evolving product designs. Foams are available in a range of colours to enhance brand recognition.
Manufactured in a Class 10,000 cleanroom, most of the packaging can be sterilized and is suited for use in a sterile environment.
Metal Fabricator Has Process Down Cold
Titanium and stainless-steel tubes from a UK-based supplier are routinely converted into intramedullary nails, cannulated screws, spinal vertebrae replacement implants, and other orthopaedic products. Fine Tubes Ltd. (Plymouth, UK) attributes its success as a supplier to this industry to the quality of the raw materials it sources and its mastery of the cold working process.
By cold working the material, the inner surface of the tubing maintains a consistent finish. This is very important if the tube requires secondary processing such as that performed to make an intramedullary nail, for example. An inconsistent finish or other flaw would prevent proper insertion of the nail into the guide instrument.
The firm recently opened a technical sales centre in München, Germany, to, among other things, provide support to its growing customer base of orthopaedic manufacturers on the continent. “We can now regularly visit our key customers and discuss their engineering requirements in their preferred language including German, French, English, Italian, Spanish, and Portuguese,” says medical business development manager Paolo Diodati.
High-Tech Materials Benefit Precision Components
A supplier of precision components made from high-tech materials reports a banner year in the development of new parts for medical equipment. Rubis Précis/Micropierre (Charquemont, France) processes biocompatible ceramic, ruby, and sapphire; vitreous carbon; titanium; stainless steel; gold; platinum; tungsten carbide; fused quartz; and optical glass into microassemblies.
Alumina and zirconia femoral heads for hip joints are among the products the firm has recently developed for the orthopaedics sector. Other device-related projects include the production of vitreous carbon electrodes for pacemakers, ruby knives for surgical use, and gold marker bands for stents.
The company attributes the increase in medical applications to the unique properties of the materials with which it works. These properties may include biocompatibility, corrosion and wear resistance, electrical and thermal insulation, and resistance to temperatures as high as 2000°C.
Orthopaedic Packaging Concept Spurs Cost Reduction
Prosthetic devices are very fragile and require protective packaging. Manufacturers typically opt for thermoformed blister packs, but this can be costly as each product line requires unique packaging, resulting in substantial tooling costs. Velfor Group (Saint-Pal-en-Chalançon, France) has developed an economical alternative.
The Velairpack system comprises thermoformed “bubbles” and a sealed elastic envelope that conforms to the shape of the device, which floats inside the blister package. A single blister design can be used to package a range of orthopaedic products, eliminating additional tooling and design costs. There is no risk of abrasion because the device does not touch the blister packaging itself. Standard packaging is now available for femoral stems, heads, and screws.
The Velairpack blister package was awarded the Prix Pharmapack 2005 at the Pharmapack event in Paris in January.
Velfor Group manufactures a range of blister packaging and pouches for implants and medical instruments. PA and PE bags can be produced on a contract basis for Class III implants. Class 10,000 and Class 100,000 cleanrooms are on-site, and the company employs a team of engineers who are dedicated to new product development and packaging customization.
Machining Firm Partners with Surface-Treatment, Sterilization, and Packaging Specialists
An extensive range of alloys and plastic materials are machined into orthopaedic products and medical devices by a specialty subcontractor knowledgeable about working exotic materials. Customers benefit by interacting with a single machining partner, according to Wyrsch AG (Freinenstein, Switzerland).
Facilities for gastight welding, cleaning stations, a helium leak-testing capability, and assembly workstations are all available in-house. The company has access to a network of reliable surface-treatment, cleanroom-packaging, and sterilization partners to ensure that customers receive a finished product to their specifications.
Orthopaedic Device Tray Sealers Ensure Parameters Are Met
Medical-grade tray sealers incorporate temperature and air-pressure process alarms, password-protected parameter setup protocols, and RFID writing and reading capability. Time, temperature, and pressure parameters are controlled though the operator interface terminal of the programmable logic controller. The sealers were developed by Belco Packaging Systems (Monrovia, CA, USA); CE-marked versions are available through the company’s UK representative, Medical Engineering Technologies Ltd. (Folkestone, Kent).
Part number catalogues used by orthopaedic device manufacturers benefit from the machine’s RFID writing and reading capability for seal fixture setup and recognition. The device self-loads process parameters by means of an RFID chip. This technology eliminates the possibility of a package being sealed with noncompliant parameters.
An autoindexing shuttle ensures consistent handling of components and packaging and allows for the use of thermal imaging for 100% documented seal inspection.
Machining Firm Has No Tolerance for Defects
Titanium and medical-grade 316L stainless steel are machined by a firm that has built a reputation on the production of tight-tolerance components with zero defects. A division of Machined Components plc, which supplies parts to the automotive and household products sectors, MCS Medical (Redditch, Worcs, UK) manufactures orthopaedic and dental implants, surgical screws, and related devices. The firm also offers bespoke R&D assistance to medical device OEMs.
Metal Fabricator Offers Full Range of Services
Specializing in the machining of titanium and stainless steel for the orthopaedics sector, a company offers OEMs a range of services beginning with the earliest stage of a project. Assistance with product development, design, and engineering; prototyping; serial production; packaging; logistics; and after-sales servicing is available. Carniaflex (Paluzza, UD, Italy) also offers laser marking, and assembly and packaging in a Class 10,000 cleanroom. The firm is certified to ISO 13485 and ISO 9001.
Materials-Testing Equipment Enlisted in Study of Fixation Devices
Following knee surgery, rehabilitation time may be affected by the degree of hamstring graft fixation to the bone. Stabilizing techniques include attaching bioabsorable screws or inserting biodegradable pins into the graft to provide extra support. In either case, it is vital to know if the implant is sufficiently flexible and stable to withstand everyday stresses. German researchers at Kiel and Westfalian Wilhelms University used a testing machine from Lloyd Instruments Ltd. (Fareham, Hants, UK) to compare the two fixation techniques.
Single and cyclical tensile loads were applied to the samples. Held in custom grips on the LR5KPlus testing machine, the samples were placed in a parallel orientation to simulate a worst-case scenario. After analyzing the maximum load results and stiffness data, the team concluded that pins and screws were equally beneficial as fixation devices.
The twin-column universal testing machine can test a variety of materials. A quick changeover of the sample grip can completely alter its functionality.
Femoral Heads Are Among Company’s Specialties
A company specializes in the production of femoral heads made from alumina and zirconia and the plasma-based surface treatment of orthopaedic implants. HTI Technologies (Décines, France) has developed a number of related products such as hard couples made from different biocompatible ceramics, humeral heads, and resurfacing heads. Plasma technology is used to coat implants in single or multiple layers of hydroxyapatite, titanium, and alumina.
Diamond-Like Carbon Coating on Implants Can Speed Patient Recovery
Prosthetic devices made from metal can cause an adverse reaction when implanted in a patient because metal ions migrate into surrounding tissue. Diamond-like carbon (DLC) coatings can prevent this from happening by imparting biocompatible, nonthrombogenic protection to the substrate, according to Diameter Ltd. (Uxbridge, Middx, UK).
Thin barrier layers of DLC applied to metal surfaces not only may prevent allergic reactions but also may provide a lubricious, wear-resistant surface. The process is used to coat knee replacements at the Royal National Orthopaedic Hospital in Stanmore, Middx, UK. The hospital uses this technique on devices that are implanted into patients allergic to cobalt chrome.
Because DLC can be deposited without external heating, it is suited for use with temperature-sensitive polymers as well as metals and ceramics. It can also be applied to recently hydrated collagen. Collagen is readily incorporated into the body, becoming vascularized and cellularized. The material is, however, thrombogenic and porous. With a DLC coating, the collagen is rendered impermeable.
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