Hip femoral stems

For orthopedic implant industries

THE COMPANY

The client is a company whose activity revolves around medical device development and manufacturing, with a strong presence in the orthopedic implant manufacturing sector. This organization is looking to enhance its position in the trauma industry, innovating and improving patients’ quality of life by minimizing rejection of the implants or premature failure.

THE PROBLEM

Despite the increase in lifespan for total hip implants over recent years, as engineers explore new designs, materials, and manufacturing processes, there remains ample room for improvement to further extend their lifespan and reduce the risk of failure.

One of the challenges faced by implants is fretting corrosion, which occurs due to the repetitive movement, exposure to bodily fluids, and mechanical stress during functionality. Moreover, the polishing and finishing processes have a significant impact on the fatigue and tensile strengths of the implants, potentially affecting their overall performance. Additionally, it is worth noting that polished implants may not always achieve complete biocompatibility, further highlighting the need for advancements in this field.

THE GOAL

The company was looking to improve the production efficiency and the quality of milled stainless steel hip femoral stems. The customer needed to surface finish stems that had been previously processed by manual polishing with belts, plastic and nutshell abrasive polishing and a final manual buffing. Concerning the polishing target, it consisted in mirror finishing surface, and a significant roughness reduction with an Ra goal of 0.03 micrometers.

THE SOLUTION

After extensive testing, the solution designed by GPAINNOVA successfully replaced a lengthy, multi-step process. This process included a hand belt station, a plastic polishing station, a walnut shell polishing station, a hand polishing station, and a waste recycling station. The replacement was achieved with a faster and cost-effective two-step process involving only hand belts and DLyte finishing. Moreover, this method satisfied all the technical specifications. These specifications encompass high-gloss polishing, prevention of premature failure and corrosion, maintenance of tight tolerances, enhancement of corrosion resistance without requiring subsequent processes. Consequently, the customer not only attained a swifter, more cost-efficient, and environmentally conscious solution for their surface finishing needs, but also ensured the biocompatibility of the treated femoral stems. This approach also preserved the laser marks on all the pieces and achieved the desired surface roughness.

Additionally, time savings with DLyte were significant. Based on a processing time of 64 minutes, the DryLyte Technology was able to achieve a high-quality surface finish a batch of 24 pieces.

TECHNICAL BENEFITS

01. Geometry and tolerance preservation & homogeneous results across the piece
02. Laser mark perfectly preserved & upper hole polishing
03. Best-in-class concerning surface roughness (Ra under 0.03 micrometers)
04. Longer lifespan for treated parts
05. Biocompatibility and non-cytotoxicity proved

OPERATIONAL BENEFITS

01. Reduced footprint
02. Time and cost reduction
03. Exposure of workers during process and maintenance
04. Handling and storage of media
05. No need for multistep processes
06. Easy waste management