Bone Screws

Achieving Specific Finishes for Trauma Implants

In our last trauma implant blog, Rosler Metal Finishing discussed the materials used in trauma implants. From hip replacements to cranial plates, there are numerous uses for trauma implants; each with its own unique surface finishing needs and requirements.

Trauma implant manufacturers must achieve the necessary surface finish to ensure patient safety and best results. These finishing requirements can range from simple cleaning or deburring to surface smoothing and high-gloss polishing.

This blog will answer the question: What techniques are used to finish off trauma implants?

What types of finishes are used?

Trauma implants are subject to multiple finishing operations throughout the manufacturing process. After manufacturing steps including forging, blanking, machining, and thread cutting for screws, the workpieces usually undergo a surface cleaning (descaling, de-oiling), deburring, edge radiusing, or surface grinding operation, before they receive their final finish.

Before insertion into the body, trauma implants generally must have a very smooth, polished surface with low Ra values.

How are these finishes achieved?

Among various technologies available, mass finishing and shot blasting play a key role in developing industry standards for finishing trauma implants across various stages from an intermediate surface treatment step during the manufacturing process or the final finish right before implantation.

These techniques:

  • Create homogeneous, all-around “isotropic” (multi directional) finishes as opposed to “anisotropic” (mono directional) surface appearances produced by machining, belt and wheel grinding, rolling, drawing, or extrusion.
  • Can handle all materials that are used in the production of trauma implants.
  • Produce consistent, repeatable finishing results with easy-to-control mechanical processes and eliminate the quality fluctuations inherent in manual finishing operations.
  • Handle a multitude of diverse tasks that range from general surface cleaning to high gloss polishing.
  • Are available in a wide spectrum of equipment, from simple, low-cost stand-alone machines to fully automated finishing systems.
A process for finishing bone plates that involves both mass finishing & shot blasting.
A process for finishing bone plates that involves both mass finishing & shot blasting.

Can shot blasting and mass finishing be combined?

Yes! Trauma implants frequently require a combined shot blasting and mass finishing treatment. Shot blasting may be used as a preparatory cleaning or peening step followed by a mass finishing process for surface smoothing and polishing.

In the example of bone plates and screws below, both implants require multiple surface finishing steps and the type of each finishing varies based on the desired results.

Are combined technologies affordable?

Both mass finishing and shot blasting technologies are highly adaptive to customer needs and offer flexible, modular solutions that can offer economical advantages.

The equipment spectrum ranges from small manual or semi-automatic machines, ideal for low production volumes, to fully automatic systems for high volume production.

For relatively simple processes, the costs per piece can be as low as a few cents. Even with more complex, multi-step finishing operations for high-value components – such as orthopedic implants – the costs for cut-down after casting/forging, followed by surface smoothing, and polishing may amount to just a few dollars – a small fraction of the total component costs.

The most significant cost reduction is achieved through the stability of the finishing process thus ensuring repeatable, high-quality finishing results with zero scrap rates.

The Rosler Way

We understand the importance of precise finishing on trauma implants. Whichever step and finishes your workpiece requires, Rosler Metal Finishing to help you find a better way and achieve exact results. Contact us today to discuss your unique challenges.

Check back for additional blog posts about trauma implants in the future.

Leave a Reply