Design for Orthopedic Instrumentation

The machining sector in the orthopedic device industry is highly specialized, especially for the production of precise technologies such as orthopedic drills, guidewires, and fixation pins. The demand for high-quality, high-precision parts continues to grow as medical devices become more intricate and patient-specific. With minimally invasive surgical procedures increasing in popularity for an ever-growing range of applications, the ergonomics and design of instruments play a crucial role in enhancing surgical techniques. Well-designed instruments improve precision in the operating room (OR), as well as operating efficiency and enhanced patient outcomes.

The most notable trend in computer numerical control (CNC) machining is the integration of automation, Internet of Things (IoT), and data analytics to enhance efficiency. Instruments with embedded features for real-time feedback and data capture are more prevalent, enabling greater precision and enhanced surgical outcomes. The integration of robotics and navigation is a key trend, especially for low-profile products that are designed for ambulatory surgery center (ASC) settings. These require accurate machining and calibration to align end-effectors with robotic systems or navigation arrays.

ASCs are enthusiastic about single-use and surgery-ready instruments and sterile pack instrument kit solutions, especially for the strong shift toward minimally invasive surgeries. “The ASC is a surgeon production line requiring efficiency and speed,” said James Schultz, vice president of sales and marketing for ECA Medical Instruments, a Thousand Oaks, Calif.-based designer and manufacturer of single-use instruments and sterile pack, surgery-ready procedural kits for medical implant preparation and fixation. “Optimized and tailored sterile pack instrument sets and sterile implants allow the implant OEMs to meet customer needs and solve active pain points.”

These capabilities allow ASC teams to improve OR case flow and turnover, improve efficiencies, and reduce operational costs.

“Ultimately,” added Kevin Rebello, global quality manager for Medical Component Specialists, a Bellingham, Mass.-based provider of orthopedic and interventional components, devices, and instrumentation, “the key focus is on enhancing manufacturing efficiency, reducing waste, and maintaining stringent quality control standards to meet the complex regulatory requirements of the medical field—thereby improving the patient experience.”

Latest Trends

Although additive manufacturing (AM) is coming on strong in the medical device space, traditional CNC machining remains the dominant manufacturing technology for surgical instruments due to its ability to provide the high precision required for orthopedic components. This is especially true for implants and minimally invasive surgical procedures.

A growing trend within the orthopedic market is the development of instruments that have a high degree of customization. Medical device manufacturers (MDM) are eager to make high-quality instruments with brand recognition that will stand out in the marketplace. “Not only are instruments expected to have multiple colors and finishes, but the trend is to also incorporate the highest level of design and detail, along with different coatings, logos, and construction techniques,” said Michael Gauthier, president of Gauthier Biomedical, a Grafton, Wis.-based designer and manufacturer of instruments for orthopedic surgery, ranging from branded multi-color ratcheting and torque-limiting handles to fully custom orthopedic instruments.

Depending on the application, customization may require the design of lightweight and ergonomic versions to reduce surgeon fatigue during long procedures. This also requires innovative material choices and advanced manufacturing techniques, such as AM, to create complex geometries without sacrificing durability. “Automation and robotics in surgical settings are also driving demand for customized instruments compatible with robotic systems, requiring extremely high levels of precision and innovative designs to ensure seamless integration,” said John Ruggieri, senior vice president of business development for ARCH Medical Solutions, a Bloomfield Hills, Mich.-based provider of precision machining, contract manufacturing, and supply chain integration for medical device companies.

Sustainability goals also influence instrument design in terms of recyclable materials, ease of disassembly, and reduction of waste. Although demand for single-use disposable products is increasing, some MDMs still prefer reusable instruments with enhanced sterilization capabilities, which reduces dependence on disposable tools. To meet these varied demands, MDMs and their contract manufacturers (CMs) use a wide range of contemporary materials, processes, and methodologies to achieve clinically robust solutions that yield measurable economic value. “These also include various polymer materials and hybrid instruments that use both polymers and steel where loads and boundary conditions dictate, as well as a wide range of manufacturing processes including injection molding of plastics, metal injection molding, 3D printing, traditional machining, and milling,” said Schultz.

What OEMs Want

Surgical instruments are tools and devices that help medical teams perform medical procedures. A surgical instrument is any component or device that supports the preparation, implantation, or maintenance of a surgical procedure. Most surgical instruments are classified by the FDA as Class II; if instrumentation is packaged with implants, it can be up-classified to Class III.

“Procedures can be anything from simple skin biopsies to joint replacements to brain surgery,” said Korey Lieser, instruments operations manager for Cretex Medical | rms, a Minneapolis, Minn.-based medical device contract manufacturer that provides engineering services, AM, metal fabrication, and precision CNC machining. “Each product has its own unique material, design, and production needs.”

Instruments also support a wide range of surgical steps including trajectory, imaging, diagnostics, telemetry, and robotics. “In healthcare facilities, it is essential to have reliable, procedure-ready surgical instruments that are always available. In the ASC, in particular, the focus is on efficiency gain for improved case flow and ability to perform more surgeries per day,” said Schultz.

MDMs are bringing surgical instrument designs to their CMs that require tight tolerances, high precision, and consistency. This is, in part, due to the growing demand by MDMs for customization and faster turnaround times. “There is also an increasing need for adaptable processes that can handle the complexities of small, intricate parts and still maintain cost efficiency,” said Rebello.

MDMs want partners that are technically adept and also strategically aligned with their goals, allowing them to deliver innovative, regulatory-compliant, and market-ready surgical solutions quickly. MDMs are also expecting their CMs to take on more responsibilities. For example, “there is a push from manufacturers to take on full regulatory responsibilities, including owning the design history file [DHF] and technical files for complete systems, alongside standard instruments, and taking on the whole project management from design to launch and early market support,” said Francois Samson, strategic marketing director for Intech Medical, a global provider of contract design and manufacturing services for mission-critical devices and components for orthopedics and surgical robotics.

Serdar Omur Goren, vice president of Sayan Orthopaedics, a Türkiye-based designer and manufacturer of orthopedic and spinal instruments and implants, is experiencing increased demand from his ortho customers for greater assistance in completing the European Union Medical Device Regulation [EU MDR] transition. “This involves gaining approval from the notified body for the technical files and clearer definition of any rework done during/post production,” said Goren. “EU MDR is still a game changer in Europe, as some vendors have decided not to manufacture for the medical market because of the requirements of MDR.”

To meet their constant need for speed, MDMs are always on the hunt for CMs that can deliver high-quality products with faster turnaround times, within compressed development cycles, and still maintain strict regulatory compliance. MDMs are asking for advanced manufacturing technologies to achieve tighter tolerances, improve ergonomics, and enhance functionality in their instruments. “MDMs also want CMs that can provide the highest-quality instruments with a production scale that can match the most demanding launch quantities and timelines,” said Gauthier. “It ultimately costs more to reject and remake sub-standard instruments than to receive high-quality instruments the first time, made exactly to the print.” 

Squeezed by time and resource constraints, MDMs also look to drive down costs by finding efficiencies elsewhere in their supply chains. For example, experienced CMs that can simplify the engineering process to find creative and cost-effective solutions are in high demand. This is where design for manufacturability (DFM) especially comes into play. “Our engineering team partners with customers to understand their needs and goals so we can advise them on the best materials and methods to build their components and devices as efficiently as possible,” said Lieser. “DFM principles enable us to reduce costs and meet deadlines without sacrificing commitment to quality.”

DFM Delivers

Making surgical instruments can be more challenging than manufacturing other types of devices and products. For surgical instruments, there are often additional layers of complexity that present different challenges compared to other types of medical devices. Running DFM is critical for identifying and eliminating unnecessary steps or technologies/features, which simplifies the design and the manufacturing processes and controls costs.

This is especially true as surgical instruments and their components become smaller and more complex. It is essential to carry out DFM early in the design process to ensure optimized production and functionality. “DFM allows us to minimize production challenges, improve cost efficiency, and enhance performance,” said Ruggieri. “Design for additive manufacturing [DFAM] unlocks new design possibilities using additive technologies for intricate and lightweight components, some with desired features that are only possible via AM. Having expertise in both DFM and DFAM ensures that customers achieve the ideal balance between innovation, manufacturability, and scalability.”

For example, Intech’s Prototype Garage houses prototype-dedicated cells at each of its production sites to foster collaboration with MDMs early in the development phase. “This ensures that technical conversations occur before design freeze so our customers feel confident when engaging in verification and validation parts and full-blown production,” said Samson.

Surgical instruments often have low-volume and high-mix production cycles, which are typically more costly compared with higher-volume implant production or shorter-lifecycle cutting tools such as drills, reamers, and taps. “The capital expenditure nature of the instruments sometimes makes for challenging delivery conversations,” said Samson. “It is our job to offer creative solutions such as holding semi-finished inventory to ensure we have safety stock on hand and offer fast turnaround times to support customer operations effectively.”

High Precision, High Quality

Dimensional tolerances in medical machining can be extremely tight—often in the range of microns—making precise quality control vital. Machine vision systems and enhanced quality inspection tools are now being used more frequently for non-contact measurement and real-time feedback. Micro machining has seen a rise in demand as medical devices and components continue to miniaturize. “With applications ranging from micro guidewires to miniature surgical tools, micro machining is expected to play a critical role in the future,” said Rebello. “Its capabilities are necessary to achieve the miniaturized, highly intricate components that are becoming the standard in modern medical technologies.”

Manufacturing complex surgical instruments with challenging geometries and tight tolerances often requires MDMs and CMs to adapt/upgrade their production and quality processes. “That is why Cretex Medical is investing in multi-tasking machines that allow for simultaneous milling, turning, and even grinding within the same machine tool,” said Lieser. “This ensures speed, precision, and repeatability. To further improve our quality process, we use computed tomography [CT] inspection technology. Non-destructive testing allows us to inspect intricate components more accurately than ever before.”

A helpful innovation for manufacturing instrument components is UV-activated adhesives, which can secure complex parts during machining, especially surgical navigation components. Since UV curing does not depend on evaporation for a complete cure, it happens almost instantly when exposed to ultraviolet light—much faster than other types of adhesives. This allows MDMs to speed up production lines and get products to market faster and more efficiently. Also, robotic dispensing systems make it easier to apply adhesives compared to manual application. “These adhesives allow precise multi-axis machining of complex or delicate components, especially when full access to the part is required,” said Samson. “There are many applications for this in the surgical navigation field.”

With constant cost pressures, MDMs look for savings wherever they can find them, including in their supply chains. MDMs have growing interest in working with partners who utilize vendor-managed inventory (VMI) systems, which reduce inventory costs and ensure critical components are always available. “VMI programs, and expanded supply chain scope, provide tailored inventory management that aligns with MDM production schedules, helping to improve efficiency and mitigate supply chain risks,” said Ruggieri.

Industry 4.0

Sensors, robotics, and automation have significantly improved process efficiency, enabling instrument manufacturers to track real-time machine performance, collect data, and predict maintenance needs. For some manufacturing scenarios, automated CNC machining has enabled lights-out operations, improving efficiency and reducing costs (no full-time staff required).

Although AM excels at creating complex geometries and prototypes quickly, CNC machining remains the preferred method for the highest precision, especially for ortho devices where exact tolerances and finishes are critical. CNC machines can produce parts at higher speeds and with better surface finishes compared to AM, as well as produce geometries that AM has yet to master, such as deep holes and intricate internal features.

AI continues to have major impacts on medical device manufacturing through analytics and real-time production monitoring. Tools like FactoryWiz, for example, are designed to capture and leverage critical machine data and metrics, such as cycle times, machine uptime, and defect rates. This enables manufacturers to identify problems faster, reduce downtime, and increase throughput. “Technology that saves money and increases production scale, while still maintaining rigorous quality standards, allows manufacturers to be even more agile and responsive to the evolving needs of the medical device market,” said Lieser.

As greater volumes of operational data are gathered and analyzed from a wide range of implant types, designs for next-generation implants (and their required tools and surgical instruments) will also evolve. In the implant market, AI algorithms are being used to monitor real-time patient data and adjust functions as needed. For example, AI-enhanced cardiac implants can detect arrhythmias and adapt pacing patterns to optimize heart function. Similarly, neural implants used in deep brain stimulation can learn from a patient’s response and fine-tune stimulation parameters, minimizing side effects while maximizing therapeutic benefits. “As implants become safer and more adaptive, we expect to see growth in the type and volume of interventional procedures, which will likely drive increased demand for specialized instruments,” said Lieser.

Continuous Learning

Many MDMs underestimate the capability of CNC machining in terms of complexity and precision. For instance, some may assume that certain internal geometries or tiny features can only be achieved with additive manufacturing. “In reality, CNC machining, especially Swiss machining and precision grinding, can handle such requests with superior precision and efficiency,” said Rebello.

Samson agreed.

“MDMs often underestimate the feasibility of creating ultra-precise, complex designs,” he added. “Advanced technologies like micro machining, laser cutting, and additive manufacturing make these achievable with reliability.”

One of the toughest challenges in the manufacturing process is geometric dimensioning and tolerancing (GD&T). Generally, MDMs only use GD&T during a product’s design stage. That data is then given to their CM, who then determines the best way to manufacture that design. “Engaging with DFM during the GD&T phase ensures that the instrument’s design not only performs the intended function, but also maximizes the efficiency of the manufacturing process,” said Lieser. “This drives down costs and speeds the delivery of products to patients. Bringing the supplier onboard early in the surgical instrument design process pays dividends in the long run.”

Looking ahead, advances in AI and machine learning for process optimization, along with improved hybrid manufacturing technologies, are expected to bring greater efficiencies. Additionally, new materials and coatings designed to reduce wear and improve performance continue to be released, further expanding machining capabilities.

The growing emphasis on sustainability will also have a significant impact on materials and designs for surgical instruments. For example, the shift toward single-use instruments reduces the environmental impact of sterilizing devices for reuse, but can also increase the amount of waste. “Finding a way to make single-use instruments from biodegradable materials, while continuing to ensure quality standards are met, would reshape the industry,” noted Lieser.

“Right now,” said Schultz, “surgery-specific, single-use kits allow the ASC team to improve OR case flow and turnover, improve efficiencies, and reduce operational costs by as much as $800 to $1,000 per surgery. They also reduce the carbon footprint by over 35% compared to traditional reusable case and tray instrument sets. These are huge and compelling end-user benefits as the industry strives to cut costs while conducting more surgeries per day.”

Staying at the forefront of technology requires a commitment to learning and ongoing improvement. The most innovative and agile MDMs and CMs likely have learning/knowledge positioned as a pillar in their corporate culture. They know how to design and develop smaller, more complex, and highly functional surgical instruments. These designers and engineers understand that achieving ultra-high precision requires advanced machining, micro fabrication technologies, and rigorous quality control processes.

These companies believe in collaborating with their customers through DFM to manage design complexities and miniaturization challenges. DFM is essential for learning—for example, the process can lead to the development of new proprietary methods and products. Additionally, supply chains with the same value systems are often willing to share their specialized knowledge (sometimes derived from work they have done in other industries). MDMs are excited to find capable partners that fit into this ecosystem and help shorten lead times, find reliable sourcing for specialized materials, provide advanced inventory management solutions, and navigate regulatory pathways.

The final key to making these elements work even more efficiently is through vertical integration, which accelerates communication, R&D, prototyping, and decision making through the immediate sharing of cross-disciplinary knowledge.

“For example,” said Samson, “Intech has developed its own proprietary processes to machine the smallest cannulated screws for small fracture. We have also actively participated in the design and development of navigation arrays and instruments with active trackers for robotic companies.”

Gauthier agreed.

“At Gauthier Biomedical, we have built our company around control of the process from beginning to end,” he said. “We have the ability to make the part complete in-house. This is unique—we are not just a general contractor, but a designer and manufacturer of the entire instrument—from beginning to end.” 

This article originally appeared in ODT Magazine.

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 more than 15 years and is the author of five books.