ZEISS Insights: Technical Papers

ZEISS Medical Industry Solutions

Quality Assurance for Orthopedic Implants

ZEISS Insights: Technical Papers

Quality Solutions for All Types of Implants

Different Implants, same Manufacturing Processes

While many different implants and fixation philosophies exist, and the solutions are diverse, the manufacturing processes of the individual components remain similar. Due to their material properties, orthopedic implants can be classified according to the manufacturing processes. This enables us to offer tailored quality solutions in the individual segments, which leads to an increase in productivity in your process. Explore the quality gates for the metal manufacturing process and the plastic manufacturing process.

Dental Implants

Due to the shape of dental implants, the thread measurement of the entire component surface is most challenging.

Shoulder Implants

A shoulder implant consists of a glenosphere, a glenoid implant, peripheral screws, and a humeral stem. The measurement of narrow stem's freeform profile is the biggest metrological challenge for this type of implant.

Spinal Implants

The full inspection of rods without datum references is the greatest difficulty in measuring spinal implants. For these implants, intervertebral discs are fixed by spinal rods and monoaxial pedicle screws.

Hip Implants

It is the low tolerance of multiple parts made of several materials that makes measurement of hip implants challenging. These implants are comprised of an acetabular cup, a polyethylene liner, a femoral head and a femoral stem.

Knee Implants

When measuring knee implants accurately, it is important to ensure that no white marks are left behind. A knee implant consists of metallic and plastic components.

Bone Implants

Bone screws and bone plates are used for implants in the field of trauma & extremities. The biggest metrology challenge of bone plates are multi-axis measurements of shallow bores on a freeform surface.

Metal Working Process

Orthopedic implants must function flawlessly even under the demanding physiological conditions in the human body. This makes it a central requirement for manufacturers to gain a deep understanding of orthopedic materials - metallic compounds, ceramic, and polymers - and the resulting organic reaction. One of the most important steps in the metal working process is assessing the raw materials properties to ensure the performance of the product. Other important challenges are the geometric dimensioning, technical cleanliness during the manufacturing process and efficiency gains through minimizing waste.

From Raw Material to Finished Parts

Quality Gates and Solutions

Stock cylindrical metal. Colored to show grain size and direction of metal domains with an image from a microscope to the top left of the cylinder.

Metallography

Analysis of Raw Material

The challenge

Assure constant quality of raw material from a micro to nano scale with respect to e.g. porosity, voids, cracks, fissures and grain size

Your benefit with ZEISS

Determine the root cause of failure to improve overall reliability

Software Solutions

Light Microscopy Systems

Electron Microscopy Systems

Initial Forging of the hipstem from stock material. Voids in blue to show possible defects in forging process. Magnified voids above the stem.

Quality of Raw parts

Inspection of Primary Shape

The challenge

Ensuring that the components are produced in good shape and without fissures voids, cracks or critical inclusions

Your benefit with ZEISS

Fast inspection of produced components to prevent cost-intensive failures later in the manufacturing process

See an application in more detail

Software Solutions

3D Scanning Technology

CT- and X-Ray Systems

Forged stem shown to show flashing form the forging process. Would be as received part from the supplier.

Incoming Inspection

Efficient Verification of Supplied Parts

The challenge

Ensuring supplied parts are within the margins for machining and processing
Fast inspection cycle times to reduce probability of bottlenecking

Your benefit with ZEISS

Programable inspection plans, which are executable in CNC
Optimize your machining time and sort out waste parts before they turn into products

Software Solutions

3D Scanning Technology

Coordinate Measuring Machines

Stem further processed. Image above shows microscope image of debris on filter. From cleaning processed part.

In Process Control

Observation of Processing Quality

The challenge

Detect and classify particulate contamination to fulfill the quality standards in the medical industry
Inspections in process steps are necessary to control the processing and avoiding unnecessary scrap.

Your benefit with ZEISS

Combine particle detection and classification in a Technical Cleanliness workflow that not only finds particles, but also helps classify them by contamination or wear origin
Avoid further processing of scrap parts

Software Solutions

Light Microscopy Systems

Electron Microscopy Systems

3D Scanning Technology

Mostly processed stem. Lines describing nominal lengths. Image above to show stylus making contact with the part to measure said dimensions.

Geometric Dimensioning

Final Dimensioning

The challenge

Critical factors for quality assurance are cycle time and the reliability of results
Tight profile tolerance on polished surfaces and complex freeforms are a challenge for traditional inspection methods

Your benefit with ZEISS

Increase usable acceptance range by decreasing measurement uncertainty
Reduce operator influence and need for manual inspection by using CNC inspection
Fast contactless evaluation of freeform surface analysis

Software Solutions

3D Scanning Technology

Coordinate Measuring Machines

Completed hip stem. Showing highlighted witness marks. A topography image above the stem shows morphological characteristic of the finished surface.

Surface Analysis

Final Visual Inspection

The challenge

Finished products have to be checked to guarantee the correct layer thickness and a flawless surface quality
Polishing results in a mirror-like finish that poses challenges for optical inspection

Your benefit with ZEISS

Fast contactless evaluation of roughness
Reproducable and fast results in final inspection

See an application in more detail

Plastic Manufacturing Process

Due to the manufacturing process, plastic implants can be produced very efficiently as large batches, but also individually. Sometimes these are customized parts that have been specifically manufactured for the patient. This is because the great advantage of plastics in medicine is that they can be shaped in a variety of ways and can therefore be adapted well to the respective needs of the patient. Especially ultra high molecular weight polyethylene (UHMWPE) has seen great successes in medical implant applications due to its high abrasion resistance, high toughness, and great biochemical inertness. The precise manufacture of the sometimes very small parts with complex geometries is now technologically possible thanks to ultra-modern machines and systems.

From Raw Material to Machined Parts

Quality Gates and Solutions

Initial geometric dimensions of stock material and shape.

Incoming Inspection

Efficient Verification of Stock

The challenge

Ensuring supplied parts are within the margins for machining and processing
Fast inspection cycle times to reduce probability of bottlenecking

Your benefit with ZEISS

Programable inspection plans, which are executable in CNC
Optimize your machining time and sort out waste parts before they turn into products

Software Solutions

3D Scanning Technology

Coordinate Measuring Machines

Processed plastic part with highlighted dimensions. Image above shows voids on the interior of the part.

Geometric Dimensioning

Final Dimensioning

The challenge

Critical factors for quality assurance are cycle time and the reliability of results
Tight profile tolerance on polished surfaces are a challenge for traditional inspection methods

Your benefit with ZEISS

Increase usable acceptance range by decreasing measurement uncertainty
Reduce operator influence and need for manual inspection by using CNC inspection
Evaluate GD&T supported by smart software tools and workflows

Software Solutions

3D Scanning Technology

CT- and X-Ray Systems

Coordinate Measuring Machines

Quality Assurance for Additively Manufactured Implants

Additive manufacturing is a modern manufacturing method. It offers a lot of potential for a wide variety of customizable medical devices: From hip and knee to spine implants, trauma components through to Patient Specific Products (PSP). To produce precise, reproducible, and FDA-compliant additively manufactured medical parts, strict quality assurance requirements must be met.

Learn more