Designing Orthopedic Devices for Additive Manufacturing

When most people picture 3D printing applications in the medical industry, they often envision innovative and ambitious use cases, such as synthetic blood vessels, bones, and even entire organs—like a new heart for someone with heart failure.

These aspirational concepts move innovation forward and may become reality in the not-too-distant future. However, prioritizing futuristic thinking can make it easy to overlook incremental innovations that 3D printing, or additive manufacturing (AM), can enable today. For example, surgeons are increasingly switching to patient-specific single-use instruments for complicated medical interventions. These customized tools can be individually 3D printed for maximum customization for the surgeon while still meeting strict medical standards.

The opportunities to leverage AM to improve current products or production processes in the here and now is enormous. In order to unlock the full potential of additive manufacturing for orthopedic design and manufacturing, however, design engineers need to ask difficult questions, get comfortable having tough conversations, and not shy away from challenging the status quo. In short, they need to start thinking additively.

The Benefits of AM
It’s important to note at the onset that additive manufacturing isn’t a universal replacement for other manufacturing processes like injection molding, polymer casting, and CNC machining. Instead, it needs to be viewed as another tool in the production toolbox. Orthopedic design professionals need to understand both where the technology excels and its limitations.

For example, AM typically performs best from a cost-benefit standpoint in low-volume production scenarios that require about half a million parts or less. While not ideal for mass production, it can be ideal for mass customization for joints or implants.

Traditionally, orthopedic implants have been produced in a variety of standardized sizes, but this might not provide the exact right fit for every person. People are unique, and one-size-fits-all has been a challenge in the orthopedic world. However, with additive manufacturing technology a hip or knee joint, spinal implant, or another orthopedic device can be made to fit the person and produced very quickly and efficiently.

Another limitation: materials cost and availability often lag for AM compared to other processes. This gap might turn organizations away from AM at the onset without realizing these perceived shortcomings create the perfect opportunity to begin thinking additively by challenging design legacy.

Yes, AM materials have slightly different properties than casting or molding, but parts designed for AM also look and perform differently than those fabricated using other processes. Ask yourself: Why is this specific material used for this specific part in the first place? Is it cosmetic, functional, or is that just the way it’s always been done? 

If you’ve always used a specific material for a functional purpose, what function does it serve? Does it have specific properties needed or required by FDA regulations? By looking at the practical elements of the part instead of simply consulting a pre-existing data sheet, you can better identify needs versus nice-to-haves and look for AM materials that will meet those demands.  

Designing for AM and Considerations for Success
When it comes to designing parts for AM, there are several questions and considerations to guide the process and ensure an organization uses AM to its fullest potential.

What problem(s) must be solved? Start by asking, “Why do I want to use additive manufacturing?” Can it reduce the overall weight of a component, simplify assembly, or even eliminate the need for physical warehouses by creating digital inventories?

AM shouldn’t be another process for creating the same part in the same way. That’s a recipe for disaster. Instead, AM is a transformative technology, one that allows design engineers to break down components into their simplest elements and rebuild in a more efficient and practical manner.

What’s the business case? Most organizations immediately look at the ROI of AM vs. other manufacturing processes and if it costs more to 3D print a part, it’s not worth it.

When it comes to AM, decision-makers must think more holistically and long-term. In an apples-to-apples cost-benefits analysis, AM may be more expensive at the onset to reproduce a single part.

Designers must challenge the status quo again. Can two or more parts be combined in the 3D printing process, eliminating additional assembly further in the process? Or can a component be redesigned to utilize less material and eliminate materials waste without forfeiting strength or durability, saving more on materials costs in the long run?

What are your goals? Set measurable, quantifiable goals at the onset of your AM journey. This will provide clear directives to employees and help ease long-term decision-making when everyone understands what the organization is trying to achieve.

Foster a learning environment. Like any digital transformation, additive manufacturing is a journey, not a destination. Mastery of the process will take time, and even then, employees will likely continue to identify areas for improvement or new ways to leverage AM for organizational success.

By creating an environment that encourages learning and exploration, employees feel empowered and engaged to try new things without the repercussions that often come with failure. And they will fail—the important thing is to fail fast, learn from those failures, and apply lessons learned from those failures to future endeavors.

Understand your level of acceptable risk. No two organizations are alike; the levels of acceptable risk between organizations—or different departments in the same organization—may vary significantly. For AM to succeed, there must be some level of investment and commitment to the technology, otherwise an expensive printer ends up in the corner of the warehouse collecting dust.

For risk-averse organizations, start small and build toward something bigger. Don’t hesitate to enlist the services of an experienced AM partner with proven expertise helping organizations successfully implement and utilize AM. The best partners have a demonstrated ability to help identify the value AM can have on their business processes in a step-by-step manner at every part of the process, from start to part.

Advancements in AM technologies over the past few years have made it less of luxury technology and more of a must-have in the medical industry, especially within orthopedic design and manufacturing, where customization is the future. Business leaders taking a short-term view of their manufacturing processes will quickly find themselves left in the dust by organizations that adopt, implement, and ultimately succeed through the opportunities and capabilities presented by additive manufacturing.