Instruments Evolve
More thought is going into how orthopedic surgical instrumentation is designed, tested.
Erik Swain
In the world of orthopedic devices, surgical instruments may not get the same attention as implants, but they are every bit as crucial to a successful operation. If an instrument is designed or manufactured poorly, or feels uncomfortable to the surgeon, there is a risk that the patient could be harmed or the implant might not be placed properly.
Since orthopedic implant designs are changing so rapidly, it is no surprise that the same is true for orthopedic surgical instruments, as the latter must be complementary to and compatible with the former.
More Rigorous Design
It is also no surprise that these days more thought is being put into how orthopedic surgical instruments are designed and made.
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“In general, we have seen a significant change in how our OEM customers are designing instruments for their upcoming instrument launches,” said Barry L. Parker, senior vice president of the Design and Developmental Center at Symmetry Medical Inc., a Warsaw, Ind.-based instrument manufacturer. “The primary focus in the recent months has shifted towards two areas. One being ergonomic instrument design, and the second being design aesthetics. The goal for these initiatives is fairly straightforward, as the overall intent is to create a unique instrument design that is easy to use and comfortable for surgeons performing surgery multiple times in one day. In addition, surgeons are asking for increased use of audible and textile feedback features in order to achieve a physical conformation of their expectations.”
Van Flamion, director of the Global Design Center at Paragon Medical Inc., an instrument manufacturer headquartered in Pierceton, Ind., agreed. “Ergonomics are important,” said Flamion.
“Surgeon-friendliness is what the user focuses on. There are the normal ‘fiddle factor’ issues, but what also must be evaluated is whether the instrument is a good, efficient use of the surgeon’s time. Can it perform a surgical task at that time in the most efficient manner? That means not having to attach and detach a bunch of different parts. It has to be simple, effective, and do the job that it needs to do. That is a big part of what drives the design of instrumentation.”
For those reasons, he said, Paragon always tries to get surgeons to provide input during the design process.
Changing Landscape, Changing Demands
These tasks are made more challenging by the changing landscape of the hospital business, said Peter Ran-dall, vice president of sales for Holmed Corp., a maker of orthopedic surgical instruments based in South Easton, Mass.
“Surgeons want something that is comfortable in their hands. A lot has to do with where a surgeon is trained,” said Randall. “Ten years ago, surgeons were servicing one hospital. Now, they work at two or three hospitals. So, their demands have changed. They do not have the same loyalties that they may have had before. They may not be using the same manufacturer’s equipment everywhere they work. So, they want more uniformity between manufacturers on things like the size of the handle and the number of steps required and the bending and other ergonomic issues that come up during the surgery.”
For example, said Duane Audette, senior estimator at Metal Craft, an Elk River, Minn.-based contract manufacturer, the comfort demands have led his company to make more instrument handles using silicone overmolds. “It has got a soft, squishy feel, which enables you to have a good grip even when your hands are wet,” he said.
Cost issues are driving changes in design and manufacturing principles, too. These include not only costs associated with the part, but those associated with processes along its entire lifecycle.
“We’re seeing a trend toward single-use disposable instruments today, many of which are made from polymer families,” said Flamion. “There are cost and processing factors for that. Current instruments can be used over and over and be re-processed, but there is a cost associated with reprocessing. So we can injection mold a single-use instrument out of a polymer and get the cost down.”
PEEK, (short for polaryl-ether-etherketone), is the most common polymer material used, but others may be employed “depending on the application and the properties desired,” he said.
“It must be biocompatible and have the mechanical and structural properties to meet the requirements of the application. If it is disposable, the structural issues are not as important because it does not have to hold up. Reusable instruments must hold up to multiple autoclave treatments over their lifecycles.”
They also must be small enough to accommodate minimally invasive surgical procedures, he said. “You have to know what new prosthetic technologies look like, and many of them demand that the instrumentation get smaller and more intricate,” he said. “We especially have to pay attention to orthobiologics.
How that evolves will definitely change the way instruments look, feel, and perform. How implant technology shifts impacts the design of instrumentation.”
These demands also affect the manufacturing process, because the designs require tighter tolerances than before, said Audette. Sometimes, he said, those demands create unrealistic ideas. “Just because you can make something in a 3-D computer model does not mean you can make it in reality,” he said. “So, sometimes we have to help with modifications of the design. Almost anything can be done; it is just a question of how much you want to pay. For example, some things can’t be made in one piece. So, we may have to make it with more than one part, or we may have to alter some design features.”
And the requirements are leading to different materials being tried out for orthopedic instrumentation applications, suppliers say.
“The orthopedics industry is constantly seeing new materials enter into the marketplace,” said Parker. “Everything from new implant materials such as PEEK to different types of instrument coatings is being consistently introduced in order to give the OEM a new look and feel in the marketplace.”
Likewise, Randall pointed out that new versions of medical-grade titanium are becoming more popular. And Audette of Metal Craft noted that “we are getting more requests for high-purity metals. For example, some people are wanting 465 (alloy) instead of 17-4.”
Another challenge is that instrument manufacturers have to do more design with computer-aided surgery in mind, Flamion said. “As technology gets more contemporary, individuals may want to try out new technologies, though of course not everyone wants to jump to high-tech,” he said.
Sterilization Issues Are a Major Factor
Sterilization issues are also forcing manufacturers to rethink how they design and make orthopedic surgical instruments. One factor to consider is that more instruments are being sterilized in Europe and Asia, where sterilization standards and methods can be different from those in North America, Randall said. “Because the dollar is so weak and many implant manufacturers have worldwide operations, they are often opting to have their instrument kits sterilized in Europe or Asia,” he said. “That means you have to be careful about your material selections, because you can’t base them only on compatibility with U.S. sterilization processes.”
Complex inspection methods ensure quality. Photo courtesy of Metal Craft. |
“We know that infection rates are still too high,” said Flamion. “Some very harsh, corrosive chemicals are being used for sterilization, especially in Europe because of the concern over mad cow disease. We have to keep an eye on the different chemicals and sterilization processes in use. So, that impacts material selection. For a reusable instrument, you have to think about how the materials you choose will survive the entire process, not just how they will hold up in the OR. For that reason, we partner with suppliers of coatings to create combinations that we evaluate.”
Also, Audette noted, welded products have come into favor, because “there is no place for biomatter to get in.” And the fewer deep holes an instrument has, the easier it is to clean and sterilize.
He noted that manufacturers can now make instruments with holes as small as .04 inches in diameter. The importance of sterilization issues cannot be understated, said Parker.
“Sterilization will always remain a major focal point during the product development cycle,” he said. “For example, cleaning and sterilization product testing is typically one of the first questions asked during conversations regarding interest in our products. We realize this is a valuable asset to the customer and we make sure this aspect is routinely covered during our product development cycle. In addition, our team has access to an independent test lab partner that gives Symmetry input on designs during the testing process. This is a valuable asset, and we take this information and apply it to current and future instrument designs. This knowledge base is a significant value-add to our veteran professional services team and is ultimately passed along to our customer base.”
Extra Reliance on Suppliers
Many instrument manufacturers have had to expand their knowledge bases, as they are being relied upon more heavily by the large implant manufacturers, Randall said.
“A lot of them have trimmed their budgets, and personnel and are relying more on fewer suppliers,” he said. “They are relying on us to do most of the design work for their general [surgical instrument] products. And they are looking for us to hold a lot of the engineering files and design history files. In the last one to two years, they are giving over control of these things. They are trying to create single-source duties. That is a major shift from how it used to be.”
Not surprisingly, he said, the driving factor behind this change is cost.
“A lot of this has to do with cost burden; they want to relieve themselves of a large chunk of time and cost,” he said. “If [an instrument company] wants their business, they must be willing to absorb the costs of these tasks, and perform the necessary training for their employees. That means things like becoming ISO certified; that is becoming a requirement for vendor firms. If you excel at things like design and recordkeeping, larger orthopedics companies will give you more business.”
That trend, Randall added, forces instrument manufacturing firms to pay more attention to the quality of the products they take on. “
There is a lot more work upfront than before. They have to consider a wider range of issues,” he said. “What factors are critical to the design? How is this product going to be tested? What happens in the field when this product gets used? There is more thought and energy going into those types of questions from a vendor’s standpoint.”
This also is true with sterilization, he said. “Before, the larger implant OEM companies would handle it. But now, because we are so much more involved on the design side, we have to think about how an instrument is going to be sterilized—and about sterilization validation procedures.”
Economics and Demographics
Of course, given the nature of the economy today, some implant manufacturers are looking for price reductions from their instrumentation suppliers. While vendors might be able to accommodate small rollbacks, implant makers need to be realistic about it. “One company asked us for a 17 percent reduction,” said Randall. “That is crazy. How can anyone reduce their prices by 17 percent? Every nickel adds up. People are paying attention to inventory levels to keep them as low as they can, and everyone wants to be competitive on price, but there are limits.” And, he noted, if firms go too far with reducing inventory, they risk supply shortages, which can lead surgeons to go with a competitor.
Regardless of temporary pricing and economic issues, however, demand for orthopedic surgical instruments is not particularly flagging. The demographic trends are not changing: More people are in need of replacement hips and knees, as well as spinal implants, at younger ages.
“Even with the economic downturn, surgical manufacturing is holding its own,” said Audette. “It may not be booming like it had been, but it’s hardly suffering.”
Erik Swain is a freelance writer based in Phillipsburg, N.J. He has covered the medical device industry for 12 years.