Collaboration Early, Success Later

Collaboration Early, Success Later

There are many benefits to seeking input from your materials suppliers early in the productdevelopment process.

Erik Swain
Contributing Writer

The importance of material selection for an orthopedic device cannot be understated. Implants must be biocompatible with what they encounter in the human body and strong enough to withstand wear. Instruments must be able to handle the force that is brought to bear on them during operations. If the wrong material is selected, there can be tremendous risks to patients. Orthopedic medical device manufacturers must know well in advance of production that they are using materials that minimize these risks.

That is why materials suppliers and materials processing firms often are sought for input during the development phase of a new orthopedic implant or instrument.

“Orthopedic OEMs are not materials experts. They do not have metallurgists on staff,” said Rich Hockman, director of sales for Veridiam Medical Inc., a contract manufacturer based in San Diego, Calif. “So companies like ours bring to the table a materials background with an expertise in grades made for the medical market.”

Some OEMs make it a point to involve outside materials experts in the development process. Others don’t. Here are some reasons why bringing your materials partners in during the development stage is beneficial to your products and thepatients for whom they are used.

Why a Partnership?

The extent to which orthopedic OEMs seek input from their material suppliers on the development side usually depends on how close in design and function their new products are to any existing ones. The more novel the new product is, the more help they are likely to need in choosing materials and processes for it.

“Most of the orthopedic OEMs I have worked with are very conservative and try to stay with materials they have used in prior applications,” said Jeff Wilson, business development manager for engineering materials at Curbell Plastics, Inc., an Orchard Park, N.Y.-based plastics supplier. “The majority of the times I hear from R&D engineers are when a known material does not appear worth testing because of material characteristics read from a typical properties data sheet, when known materials have failed in early testing, when they have read about a new material and have no experience with it, when cost control is a consideration, or when they are working on a component outside of their area of expertise.

“If they are considering a new material, or using a known material in a radically different way, they should get a plastics professional involved as early as possible to minimize redesigns and testing,” he added. “Having spent time working in the medical market segment, we are familiar with most of the compliances required for polymer materials.”

Because of all the testing and potential risk associated with novel materials, OEMs will try to use substances that they already are familiar with, said Mike MacKay, president of MacKay Manufacturing Inc., aprecision manufacturing contractor in Spokane, Wash.

“Most of the time we get involved once the drawing is finished and the design is fixed. We bid the project to the drawing specifications and seldom are able to suggest or implement DFM (design for manufacture) solutions,” he said.

However, he added: “A few of our long-term, sophisticated customers do just the opposite. They ask us for DFM ideas at the earliest stages and, where possible, toimplement the ideas for cost reductions.”

In the ceramics area, orthopedics OEMs often look to materials experts to keep them updated on new varieties, and to test them, according to Andrew Nield, director of sales and marketing for C5 Medical Werks, an international medical ceramics firm based domestically in Grand Junction, Colo. “OEMs are always looking for new technical ceramic materials,” he said. “They want materials that perform better, but they also want materials that have been tested by the ceramics manufacturer so that they meetISO standards, U.S. Food and

Drug Administration standards andASTM (American Society for Testing and Materials) standards.”

On the materials processing side, OEMs often look to a processing partner “to work as an extension of their engineering and manufacturing operations, to bring the correct material suppliers together to work with them to help develop a device and design a manufacturing process for it,” said Mark Schaefer, corporate vice president of business development for Spectrum Plastics Group, a materials processor based in Minneapolis, Minn.

Given that in recent years medical device companies have outsourced functions that are not their core competencies, it is no surprise that they now are outsourcing some tasks related to materials development that they used to do in house.

Wilson said that one function Curbell often now performs is “compiling and presenting material performance data from the polymer resin manufacturers. With many polymers being notch sensitive, I have helped make some recommendations to part geometry that help improve part performance.”

Nield said firms such as his are being asked to design customized ceramic materials, rather than sell commodity ones. “This allows the OEM to differentiate based on ceramic material performance as an added benefit to their device,” he said.

Some functions still performed in-house may be done by people without much experience, so it often is a good idea to get the materials partner involved in those, too, said MacKay.

“Many times you assume that the engineer has already looked at these issues prior to setting the design to paper. Many times you will be disappointed,” he said. “It is common for the large companies to use engineers fresh out of school and they have not had enough experience to know about the different technologies available to them.”

Getting Started

When beginning a project, all parties involved must have a full understanding of its scope, said Nield.

“I think it is important to understand what the project scope is from the outset so that the material supplier and OEM fully understand who is developing which technology, so that there are no overlaps or gaps,” he said. “It is also important to understand the three main elements of project management related to the OEM’s project: specification, timeline, and cost.”

Spectrum’s Schaefer agreed. “We need a full scope understanding of what the OEM is attempting to accomplish, so that we can bring the correct resources to bear,” he said. “The discussion may even extend to regulatory recommendations, especially if we are dealing with smaller startup organizations.”

To facilitate this, materials partners should be involved “at the pencil-drawing-on-a-bar-napkin stage,” said MacKay. “Ask the supplier what they suggest for raw material, what type of machine tool that is best, what post processing is available in the area, whether there are any long lead time items on the BOM (bill of materials), whether they can use standard hardware, and related questions.”

In turn, the materials partner should have a long list of questions for the OEM that will assist in the design-for-manufacture process, MacKay said.

“In no particular order, we suggest raw material that we are familiar with and have the ability to heat treat in house,” he said. “We ask about tolerances, whether there is need for extremely tight ones and whether the part will work as well with more open tolerances. For example, can we have a larger radius here or there? How important are cosmetics? What are the best ways to achieve those requirements, and do we have that capability in house or do we have to send that to someone else? We also need to know how many parts will be ordered at a time, how many will be delivered at a time, and if there any packaging requirements.”

If the part is complex, a number of other issues will need to be addressed up front, explained MacKay.

“In that case, we may ask about the chance to make it from a casting or an extrusion,” MacKay told Orthopedic Design & Technology. “Sometimes the issue of standard size material comes up in the conversation. If they have specified a special round bar that only comes in a few sizes, then we are forced to buy the next size larger and waste the extra. I have seen surgical instruments that must start with a three-inch-round bar because of availability and end up with a one-inch-diameter part. If they had changed the raw material to one that was more available, the waste could have been eliminated.”

If the project consists of making a new version of an existing product, the first meeting between the OEM and its materials partner should go over materials-related challenges that the current design faced, said Hockman. “We ask the OEM what technical issues related to materials they have in the current design,” he said. “Strength? Sharpness? Ductility? Then, 99 percent of the time, we can iterate off of the design given those issues we’ve been told about. It may be that an orthopedic surgeon can only use an instrument 80 percent of the way through a procedure, and then he has to switch to another one. That’s a signal that we need a particular material that can last longer in the application. Also in orthopedics, a surgeon tends to use a lot of blunt force in his procedures. He may have to do a lot of bending of the instrument, or putting excess pressure on it, which means the product breaks or wears down during the procedure. That indicates that the strength of the material may be an issue. So we have to talk about what areas the OEM is looking to improve upon.”

Once that discussion has happened, the materials partner usually can recommend some materials for the application,Hockman said.

“We then give the OEM technical data sheets showing what the materials’ properties are, and they can compare them to what they are using now,” he explained. “For example, if they are using 304 stainless steel, they may want to upgrade to 455 or 465, which offer more strength and corrosion resistance.”

Sometimes the discussion will involve multiple materials experts.

“This depends upon the OEM,” said Nield. “Some prefer us to work with the OEM only and some prefer us to work with their other suppliers. This really depends on the culture of the OEM. Typically, the larger OEMs have more technical resources and prefer to manage the project in-house as they feel this is a good way to protect their IP (intellectual property).”

There is more to the process than just discussion. Often, the input from materials experts will result in prototypes that are used for real-world testing, accordingto Hockman.

“They may have surgeons actually try out a new instrument design, because there’s a feel to it,” he said. “Surgeons usually end up with a preference for a certain weight, ductility, and strength. The OEM may test out a couple of materials at once with them.”

Things to Remember

There are certain considerations that easily can be overlooked during materials selection, and OEMs may need to rely on their partners to help ensure that they are adequately addressed.

For example, said Wilson, OEMs sometimes select a material because of a single property, when they should be taking into account a number of different properties. That may work with metals, but it will not work with plastics.

“Plastics are very different than metals and have certain characteristics that must be taken in to account when making a polymer material selection, so the engineer must consider multiple typical properties of a material when making a selection,” he said. “Some of the characteristics are creep, resistance to steam for sterilizing, modulus degradation, and chemical resistance, just to name a few.”

OEM personnel also should keep in mind that the materials suppliers are most likely more familiar with the full range of materials that could be used than they are, said Hockman.

“Companies like ours have access to materials previously not known to OEMs,” he explained.

“Once they realize they are able to use different materials to solve their technical problems, that excites them. As procedures become shorter and less invasive, orthopedic tools and products must stand up to greater rigor than they have in the past. New materials can help solve those problems.”

Making the Decisions

Final authority for materials selection almost always falls to the OEM.

“This is mostly done, in my opinion, because of liability reasons and so their subcontractors do not substitute materials of a lesser quality,” said Wilson.

However, the members of the OEM’s team who are responsible for that decision should have a strong sense of what input they need from their partners.

“All we can do is help them not waste time considering, designing, or testing with products that most likely will not perform adequately in the application,” said Wilson.

MacKay agreed. “We are not designers or engineers, so we do not make any decisions on raw material,” he said. “We suggest materials that may be cheaper, easier to machine, obtain, heat treat, paint etc. Our customer always has the final approval of raw material.”

Materials partners can be particularly helpful when it comes to doing analysis, said Nield.

“We design the formulation of our own materials using the laboratories of our parent company, which is the largest technical ceramics manufacturer in the world,” he said. “This gives us the opportunity to analyze new materials down to the atomic level. In developing a material, we have free reign, but the end result must be a material that will pass OEM and U.S. Food and Drug Administration scrutiny, along with efficacy, plus cost and manufacturability constraints.”

Schaefer said that while OEMs almost always reserve the final decision on material choice for themselves, sometimes they let their partners take the lead on processing issues.

“Once we’ve sat down with the OEM and fully understood the scope of the project, we frequently take the lead role on bringing all the correct people together,” he said. “For an injection molding project, that could mean the mold maker, the processor, the materials supplier, and whoever else needs input up front to ensure a good and safe product with an appropriate shelf life. So we often will function as the extension of the manufacturer’s engineering and manufacturing operations, but all design and sterility issues remain the OEM’s.”

Best Outcomes

Allowing your materials partners to give input in the early stages of new product development can save much time and money over the long haul, and produce better and safer orthopedic implants and instruments. When it comes to making decisions on materials, OEMs should not be strictly considering price, but should have confidence that the right choices will eventually produce cost savings thanks to manufacturability and safety.

“Customers are always looking to reduce their costs on instruments but are seldom agreeable to design changes after the drawing has been approved,” said MacKay. “The price of the instrument is primarily dictated by the design, the BOM, and the ability of the customer to place that item in a shop that specializes in that niche market. If the customer gets the supplier involved very early in the design process, provides reliable annual usage forecasts, and uses long-term agreements on the purchasing side, the outcome will be best.”

Erik Swain is a freelance writer based in Phillipsburg, N.J. He has covered the medical device industry for 13 years.