Instrument Manufacturing Leads Toward Smarter Surgeries

According to Allied Market Research, the global surgical equipment market is expected to grow at a compound annual growth rate of 6.3% by 2027.¹ Innovation in this category is driven by the ever-widening applications for creative robot-assisted and minimally invasive (MI) surgical procedures. Surgical instrument design, material selection, and manufacturing are trending toward more complex, multifunctional instruments that help surgeons perform procedures with more efficiency, resulting in less risk to the patient and shorter time on the operating table. These tools have a variety of uses, ranging from shaping and holding to access, visualization, and removal of medical implants. They can be either reusable or one-time disposable instruments for both mini-open or MI surgeries.

Instrumentation embraces any component used in a surgical procedure that does not remain in the body. These include taps and drills, as well as the normal retractors, holders, and screwdrivers. Robotics and supporting navigation tools are also considered instruments. Disposable instruments are becoming more popular in hospitals for reducing infection risk and the cost of sterilization. Additive manufacturing (AM) methods can also be used to create customized instrumentation, often with fairly quick turnaround times, for scheduled surgeries.

A steady transition is under way toward single-use and surgery-ready solutions to support ambulatory surgical centers (ASC). “Optimized and tailored procedural sets and sterile implants allow for faster operating room turnover and, hence, more cases per day for surgeons who see the ASC as their production line,” said James B. Schultz, vice president of customer solutions for ECA Medical, a Thousand Oaks, Calif.-based designer and manufacturer of high-precision single-use instruments and sterile pack procedural kits and delivery systems for orthopedic and spine procedures. “Solutions that provide excellent outcomes while reducing costs and reprocessing are the way of the future for the outpatient setting and many busy emergency departments for upper and lower extremity fracture repair.”

Like all medtech companies, orthopedic device manufacturers are still stressed by wobbly supply chains and sudden material availability problems, often accompanied by volatile price swings. Staffing is also increasingly difficult to manage and labor shortages can slow down production. All these factors have negative impacts on lead times, on-time delivery, and capacity, but most OEMs and their contract manufacturers (CMs) have found workaround solutions to keep production going.

Such challenges, however, “also present opportunities to rise above and improve operations, and that is what we are doing,” said Michael Gauthier, president of Gauthier Biomedical, a Grafton, Wis.-based biomedical designer and manufacturer of advanced instruments for orthopedic surgery. “We are focused on specific areas of our business to provide a more consistent supply of instruments for our customers.”

What OEMs Want

OEMs are asking for more services from their supply chain partners, at less cost. To keep costs down, OEMs want their CMs to get involved earlier in the design for manufacturing process (DFM) to troubleshoot materials and design, reduce assembly steps, maximize production, and get high-quality, differentiating products to market as quickly as possible. Orthopedic manufacturers often push their CMs for quick turnaround on prototypes and shorter production lead times, which can sometimes be accomplished with AM equipment or hybrid AM/computer numerical control (CNC) machines.

A simple way to reduce cost and improve operating room (OR) efficiency is to transition toward single-use instruments. Reusable orthopedic instruments are some of the most complicated devices in the medical world, with many components, complex assemblies, and moving parts that must fit perfectly together. For example, a retractor can have 70 or more components. Therefore, OEMs view single-use (disposable) devices as a way to deliver the same high performance at lower cost, while also reducing the risk of healthcare-associated infections, a serious problem in hospital environments.

Ultimately, medical device manufacturers (MDMs) are always on the hunt for high-performing suppliers that can troubleshoot and innovate and provide the highest-quality instruments, on time. These MDMs realize that, overall, it takes more money and time to reject and re-design sub-standard instruments than to produce high-quality instruments the first time, which are made exactly to specification for high-performance applications.

“Our customers weigh their options regarding cost, on-time delivery, and quality,” said Justin Meyers, vice president of operations for Carolina Precision Technologies, a Putnam, Conn.-based provider of precision-machined spine and orthopedic instruments and implants. “We hold all these factors in high regard and rely on design for manufacturing at our quoting stage to help reduce costs, lead times, and improve quality and function.”

Surgical instruments are designed to enhance surgeon performance and reduce the amount of time a patient is in surgery and recovery. “Robotic instrumentation is advancing rapidly as robotic surgery becomes more accepted in the medical space,” said Alice Higdon, vice president of sales for Trimaster, a Guelph, Ont.-based manufacturer for surgical instrumentation, including milling, turning, 5-axis machining, lathe, deep gun drilling, and grinding. “With the increase in surgeries performed in ASCs, disposable instrumentation is gaining a larger foothold as well. Disposable instruments are also gaining traction in hospitals as a way to reduce the cost of sterilization.”

To meet these growing needs, OEMs are producing and delivering clinically robust instrumentation that provides distinct economic value and improves patient outcomes. Most implant OEMs sell single-use instruments with their implants, turning instrumentation from a cost center with reusable case and tray models (on loan or consignment) to a profit center in selected market segments. Distributors worldwide are interested in adopting single-use solutions because they reduce their cost of sales per transaction and eliminate the hassle of reprocessing.

“With multi-year sterile shelf life, the single-use sets are procedure-specific and optimized instruments that are always ready for use with sterile implants,” said Schultz. “It means a sales rep never loses a sale because the instruments and implants are not ready for use. This risk was highlighted during the recent pandemic when reps could not get into the operating room or meet with their surgeons.”

OEMs also want instruments that have a high degree of customization. “Not only are instruments expected to have multiple colors and finishes, the trend is to incorporate the highest level of design and detail along with different coatings, logos, and construction techniques,” said Gauthier. “OEM customers are looking for high-quality instruments with brand recognition and our team of designers looks forward to enhancing these full instrument/implant systems.”

CM vertical integration is also valued by OEMs as a way to reduce costs, improve communication, develop in-depth partnerships, and speed up time to market. “At Gauthier Biomedical, we have built our company around control of the vertical integration process, from beginning to end, giving us the ability to make the part completely in-house,” said Gauthier. “This is not common in the industry—we are not just a general contractor, but also a designer and manufacturer of the entire instrument.”

Of course, as medical device designs become smaller and more complex, DFM is increasingly important for reducing iterations, improving design, and streamlining production.

“It is very beneficial to get all manufacturing partners involved early and reduce time to market by optimizing the design earlier for the most efficient and cost-conscious manufacturability,” said Meyers.

The main goal of DFM is determining the most effective materials and manufacturing technologies (or combination of technologies) for a new product design. For example, engineers at the Department of Biomechanical Engineering at Delft University of Technology in The Netherlands have used AM to design and build a new, fully 3D-printed handheld steerable instrument for laparoscopic surgery, which is mechanically actuated using cables. AM processes allowed the team to reduce the number of components while still improving the functionalities of the final design. “The pistol-grip handle is based on ergonomic principles and allows for single-hand control of both grasping and omnidirectional steering, while compliant joints and snap-fit connectors enable fast assembly and minimal part count,” stated lead researchers Costanza Culmone and Kirsten Lussenburg.²

One of the greatest benefits of AM for this design is that it enables personalization of the handle to meet each surgeon’s grip by adjusting specific dimensions in the CAD model, which increases the surgeon’s comfort during surgery and reduces fatigue. “The instrument combines the advantages of additive manufacturing with regard to personalization and simplified assembly, illustrating a new approach to the design of advanced surgical instruments, where the customization for a single procedure or user’s need is a central aspect,” added Culmone and Lussenburg.

Material Choices

Surgical instruments are made from a variety of materials to ensure the highest level of performance. Preferred materials are surgical-grade stainless steel, ceramic, tungsten carbide, titanium, polyetheretherketone (PEEK), and nitinol. Titanium’s nonmagnetic properties make it an ideal choice for surgical instruments that are used in magnetic resonance imaging (MRI) environments. Nitinol, a nickel-titanium alloy, is known for its unique shape memory, biocompatibility, and exceptional elasticity under stress, making it a good selection for instruments such as stents, dilators, suction cannulas, ablation catheter tips, orthopedic implants, and wires for locating breast tumors.

“PEEK is an attractive precision plastic in the medical field because of its abrasion resistance, chemical resistance, high ductility and elongation, hydrolysis resistance, and low outgassing,” said John MacDonald, president of AIP Precision Manufacturing, a Daytona, Fla.-based designer and high-precision manufacturer for the orthopedic industry. “These qualities make PEEK a material pick for medical procedures inside the body or in the operating room.”

A popular PEEK material for orthopedic applications is TECATEC PEEK MT CW50. These black plates of PEEK are reinforced with 50% by volume carbon fibers. “This reinforcement elevates the stiffness and strength to be many times those of plates made from unreinforced PEEK, or plates with short-fiber reinforcement,” said MacDonald. “It is also autoclavable as it shows no significant loss of mechanical properties or degradation, even after many sterilization cycles. It is suitable for gamma sterilization and is X-ray transparent, making it an ideal material for medical applications in multi-use conditions. Applications range from the orthopedic market, with the joint reconstruction and traumatology segments, to surgical instruments and the dental market.”

Glass-fiber-reinforced specialty polymers (including PEEK) are formulated to be strong enough, and temperature- and chemical-resistant enough, to replace metal components in medical devices, resulting in lower-cost, lighter-weight surgical instruments that are easier to use and can still withstand harsh sterilization environments. Other benefits of these specialty polymers are improved stiffness, rigidity, and strength.

“Advanced materials that are partially glass-filled, 3D-printed, or machined allow for broad application in demanding spine and large joint procedures and for tight tolerance navigation for MI surgery and arthroplasty procedures,” said Schultz. “Manufacturing of molds, expertise in injection molding of resins, and ability to meet critical quality tolerances with an acceptable quality limit [AQL] in-process inspection criteria, are crucial to a predictable instrument. We are making single-use, surgery-ready instruments and procedural kits for essentially all orthopedic and spine procedures, including demanding lumbar spine, sacral joint, instruments with infrared trackers for robots, and for large joint arthroplasty navigation that, until recently, was dependent on costly reusable instruments.”

Popular coatings include chrome, titanium nitride, diamond-like carbon, and aluminum titanium nitride for corrosion resistance, improved function, and aesthetics. “These types of coatings and their use on instruments, for both function and aesthetics, are helping to create a new class of instruments,” said Gauthier. “The instruments look so good they help sell the implants.”

New coating materials that enhance the performance of surgical instruments continue to be developed. For example, NChemi Engineering Nanomaterials, a spin-off company from the Center for the Development of Functional Materials (CDMF) in Brazil, has developed Plenus Duty—a coating for medical and industrial applications that can increase the hardness of a metal surface by 90% and reduce the friction by 50%. This unique material is deposited as a thin nanometric film of zirconium less than 0.2 microns in thickness on stainless steel surfaces. The coating can be applied to surgical instruments of any size and shape—without the need for any modification or pre-treatment—and maintains its sharpness and durability for a longer time period compared to diamond coatings.

A Smart Future

Manufacturing is advancing at a rapid rate due to deployment of AM, Industry 4.0, and Internet of Things (IoT) technologies, all of which enable the digitalization of tools, processes, and devices. Many of these gains are due to improvements in software and artificial intelligence (AI)—for example, vision-based AI surgical tracking technologies utilize machine vision, pattern recognition, and deep learning to analyze positional images captured by a robotic endoscope to evaluate a surgeon’s navigational skills.³ The movement and orientation data are extracted from the surgical instrument and analyzed to assess the surgeon’s skills and navigational abilities.

A new class of medical instruments, equipped with a soft electronics system, improves diagnostic and therapeutic cardiovascular interventions in MI surgeries. Scientists at George Washington University and Northwestern University applied stretchable and flexible matrices of electrode sensors and actuators, along with temperature and pressure sensors, to a balloon catheter system. The new system performs a variety of functions, including simultaneous in vivo measurements of temperature, force of contact, and key electrophysiological parameters, all in real time, during a surgical procedure. The technology dramatically reduces the length of invasive ablation procedures and the amount of time that patients and doctors are exposed to X-ray radiation.⁴

“We have taken new breakthrough materials and fabrication techniques typically employed by the semiconductor industry and applied them to the medical field, in this case cardiology, which will improve cardiac outcomes for patients and allow physicians to deliver better, safer, and more patient-specific care,” said biomedical engineering professor Igor Efimov, part of the George Washington University research team.⁴

Digital enhancements to handheld and robotic surgical tools enable tracking and other capabilities in the operating room. Surgeons can use up to 250 different tools during a surgical procedure to perform a variety of tasks, including cutting, cauterizing, suturing, suctioning, and bleeding control. Hospital staff must manually count each tool, both before and after surgery, to be certain none are missing, which is a tedious and time-consuming process.

However, a radio-frequency identification (RFID) chip and antenna can be embedded into metal surgical instruments during the manufacturing process and sealed with a biocompatible sealant, allowing tools to be tracked during and after surgery. The Wyss Institute at Harvard University, in collaboration with clinicians at Brigham and Women’s Hospital, tested a vapor deposition process to deposit a dielectric material directly onto the tool’s metal surface, pattern a conductive antenna on top of the dielectric using sputter techniques, and attach and seal an RFID chip to the antenna. This system successfully wirelessly tracked and counted the instruments via an antenna in the operating room.⁵

Xerafy has also developed and validated a medical-grade RFID technology that uses ultra-high frequency RFID tags embedded in surgical instruments. Using this system for surgical instrument tracking, Rigshospitalet in Denmark estimated it saved 31,000 hours a year in OR procedures alone.⁶

During robotic surgeries, surgeons must adjust the laparoscope frequently to provide a better field of view, which increases their workload and leads to longer procedures, with more surgeon fatigue. Scientists at the Department of Biomedical Engineering in the City University of Hong Kong in China have developed a data-driven control method that automatically adjusts the field of view through the laparoscope. Using a deep learning method, the system can predict the position of key points on the surgical instruments, allowing it to identify their precise location and readjust as needed. “By automating the task of laparoscopic view adjustment, we hope to lay a foundation for the development of more intelligent surgical robot systems,” said lead researcher Hangjie Mo.⁷

As the orthopedic field moves forward and continues to innovate, “emerging capabilities such as artificial intelligence, machine learning, and next-generation sequencing technologies will deliver new and powerful ways to provide more cost-effective treatment of illness and disease and advanced surgical instruments and implants will continue to transform the industry,” said Brad Womble, senior director of strategy, marketing and mergers and acquisitions for Jabil Healthcare. 

References

1. bit.ly/odt230141
2. bit.ly/odt230142
3. bit.ly/odt230143
4. bit.ly/odt230144
5. bit.ly/odt230145
6. bit.ly/odt230146
7. bit.ly/odt230147

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Mark Crawford is a full-time freelance business and marketing/communications writer based in Corrales, N.M. His clients range from startups to global manufacturing leaders. He has written for MPO and ODT magazines for over 15 years and is the author of five books