Orthopedic devices play a crucial role in providing pain relief, improving mobility, and enhancing the quality of life for patients suffering from musculoskeletal disorders. The medical devices and procedures used in orthopedics are constantly being upgraded due to changing consumer needs. Technological advancements and integration of digital technologies have triggered changes in demand, for patients and healthcare professionals alike.

With additive manufacturing, orthopedic implants can be done quickly and precisely in greatly reduced timeframes. (Image courtesy of Ampower GmbH & Co. KG, and YXLON International FF35 CT High Resolution Industrial CT System)

The challenge of the top players in the global orthopedic device market is to develop devices that have all these features and maintain affordability. Research, development, and investments in collaborations are predicted to rise to facilitate enhanced product portfolios. Because of these factors, the healthcare sector is adopting additive manufacturing (AM) at an astonishing pace. Major manufacturers are even using AM in regenerative medicine, tissue engineering, bioprinting, and other advanced processes.

The growth of the orthopedics market poses a huge opportunity for industrial computed tomography (CT) as a quality inspection tool for this highly regulated industry, where quality and safety are of the utmost importance. This article explores how CT can be a valuable tool for design and quality engineers to help them ensure that their critical products meet and exceed regulatory standards. This article also details the benefits of CT for AM.

Orthopedic Device Industry

According to a recent report by Frost & Sullivan, the orthopedic devices industry will continue to grow in the global medical technology space and is expected to rank third in sales volume after cardiology and in-vitro diagnostics by 2020. The market is predicted to reach $43 billion by 2024. Some key factors driving the growth include:

  • Steady rise of degenerative disease.

  • Growing geriatric population.

  • High prevalence of obesity and sedentary lifestyles.

  • Early onset of musculoskeletal disorders.

The demands of the market have driven the early adoption of technological advances and new product launches. Manufacturers have made significant enhancements to implant materials and processing methods of implants, which has made them more reliable and durable over extended periods of time. For example, manufacturers are developing implants made of a new type of polymer called highly cross-linked polyethylene (HXLPE), which will significantly extend the lifetime of implants.

Careful inspection of a hip cup with industrial CT, while they are still in the design phase, helps to ensure that the hip cup matches all specifications before it goes into production. (Image courtesy of Ampower GmbH & Co. KG, and YXLON International FF35 CT High Resolution Industrial CT System)

What's Hip? New Technologies

Additive manufacturing, also known as 3D printing, is gaining momentum in the orthopedics industry with the production of customized implants, medical devices, and orthotics from diverse materials. AM technology reduces surgery times, allows for custom design, leads to better stability of the implant in the long run, and is improving the clinical outcomes of surgical procedures.

  • Instruments: Polymer printing technologies is used to customize surgical guides that improve surgical precision.

  • Patient-Specific Implants: Metal 3-D printing is used to create patient-specific implants. Micropore structures promote improved biocompatibility between metal and bone.

  • Anatomical Models: Polymer implant models allow surgeons to prototype and review compatibility before an actual surgery.

  • Biologics: This AM technique produces tissues and simple structures for surgical repair.

Additive Manufacturing in Healthcare

AM is becoming a valuable tool in the healthcare market for several reasons. One of the most important is the freedom of design it offers for complex structures. Another is the ability to personalize devices to fit individual patient needs.

Another medical application where AM is having a big impact is the ability to rehearse before procedures. Surgeons can use data from MRI and CT scans to build 3D models of the patient's anatomy they will operate on. They then use this 3D CAD data to manufacture 3D printed models, enabling them to practice challenging surgery techniques on realistic models to perfect technique. This allows surgeons to be more precise, reduce risks, and operate faster, all of which helps deliver better clinical outcomes.

Hip replacement candidates today are trending younger and tend to be more active with lifestyles that include biking, swimming, and even jogging. Providing implants to these atypical patients requires a new design and manufacturing approach. Orthopedic implants that are designed specifically for the patient can be very expensive and time consuming to make using traditional manufacturing techniques like casting or forging, but with AM they can be done quickly and precisely in greatly reduced timeframes. Two of the major advantages of 3D printing for these applications are the ability to use patient-specific data to build the implants and the ability to create matrix or lattice patterns on the surface of the parts. These patterns aid osseointegration and reduce rejection.

Industrial CT Connects All the Parts

The human body consists of more than 37 trillion cells, 100 billion of which are brain cells, 206 bones, and 340 joints. If that isn't complex enough, imagine having to build and inspect an implant device to replace one of those parts. The more intricate and complex the structure is, the more difficult it can be to work with. This can create quite a challenge for busy manufacturing plants to remain productive. That is where the power of industrial CT can help to connect all the parts together.

CT scanning is often the best solution for nondestructive measurement of objects with complex shapes, because it is a non-contact technique that doesn't require line of sight to the region of interest. This is especially important when it comes to something as intricate as the creation of an implant. Even though no human body is exactly like another, implants must fit perfectly and be biocompatible so that they can bring about a long-term improvement in the patient's quality of life. So, for example, a hip implant requires a very complex structure for bonding to the organic structure.

3D printing allows a part like this to be built, but inspection can present a huge challenge. It can be impossible to inspect a component with traditional methods of laser, light, or contact metrology. CT is often the best technique for a comprehensive inspection.

Initial Part Design

Today there are more than 100,000 hip cups being produced annually by additive manufacturers for use in hip replacement surgeries. They are made in very standard sizes such as small, medium, and large, which are then fit to the size of the patient. Careful inspection of these parts with industrial CT, while they are still in the design phase, helps to ensure that the hip cup matches all specifications before it goes into production. This is a critical step because the lattice structure needs to be just right in order to help the bone to grow in through the implant.

CT scanning can be the best choice for nondestructive testing of medical implant products producing the most complete, accurate data in a short amount of time. (Image courtesy of Ampower GmbH & Co. KG, and YXLON International FF35 CT High Resolution Industrial CT System)

Certifying the Process

Another important step is to certify the process being used to print the part, which is very important in the highly regulated medical industry. This includes finding the best powder and identifying the best parameter settings for the process to print the specific design needed. This can take months to set up correctly. Industrial CT can speed up the process with proper inspection of powder quality and faster identification of the parameters.

Some of the typical flaws that come from the powder bed fusion process such as porosity, lack of fusion, balling, excessive surface roughness and entrapped powder, can be resolved and quantified simply with CT. If, for example, powder remains inside the sample, it could be very dangerous for the patient receiving the implant because the human body could absorb the titanium powder into their bloodstream. The CT scan data makes it fast and easy to identify these issues sooner, thus reducing time and increasing productivity.

Better Quality Assurance = Better Quality of Life for Patients

Today's patients are more educated about their healthcare options than ever before. With information at their fingertips, they can compare treatments and success rates among hospitals and physicians alike. When it comes to orthopedic implants such as hip or knee replacements, patients are expecting the outcome to eliminate pain, improve mobility, and provide better quality of life.

AM is a manufacturing method that has been shown to solve clear and persistent problems in orthopedics. Utilizing industrial CT as a quality control tool can help to deliver on the promise of better healthcare products for patients worldwide. CT scanning can be the best choice for nondestructive testing of medical implant products producing the most complete, accurate data in a short amount of time. This technology will enable its owner to keep up with the demand for high-quality orthopedic specialty products.

This article was written by Jeff Urbanski, Key Account Manager with YXLON, Hamburg, Germany. Nils Achilles, MSc, YXLON Sales Manager, Science & New Materials, contributed to this article. For more information, visit here.