Endocon GmbH, a German medical device company, has turned to additive manufacturing to improve hip and knee replacement surgeries. The company utilized metal AM technologies from GE Additive to create the endoCupcut, an innovative medical device that makes hip cup extraction easier, more cost effective and more reliable.
In an increasingly aging population, there are certain things that need to be addressed. For one, medical professionals are seeing a growing need for hip and knee replacement surgeries. The operations, which are performed on hundreds of thousands of people per year, have become fairly commonplace in the medical world and are typically safe and straightforward.
If any loosening, abrasion or infection occurs to the patient, however, the removal of a hip cup can present a range of difficulties for surgeons. Traditionally, medical professionals have relied on a rudimentary chisel to remove the hip cup, which—as one can imagine—comes with all sorts of risks: the bone and tissue can be damaged or the removal can result in an uneven surface which makes putting a new implant in all the more difficult.
To confront this challenge, Heidelberg-based Endocon developed an acetabular cup cutter, which helps in the hip cup removal process by making it easier and less risky. Crucially, it also allows surgeons to dramatically reduce operation times.
The medical device, which integrates 3D printed blades, was developed using GE Additive’s Concept Laser DMLM technology (and specifically its Mlab cusing 100R machine). The blades are designed to precisely cut along the edge of the acetabular cup, which gives surgeons the ability to loosen and extract cementless hip cups without compromising the patient’s bone. Because of the endoCupcut’s high precision, surgeons are even able to implant the same size hip cup into the patient once the removal is complete.
The reusable medical device can be fitted with up to 15 3D printed blades made from stainless steel and ranging in size from 44 mm to 72 mm. This means that depending on the patient, surgeons can choose the most efficient size of blade.
By using additive manufacturing to develop the medical device, Endocon saw a number of benefits over traditional manufacturing processes such as casting. For one, 3D printing the blades sped up the production time dramatically. While it would have taken up to three and a half months to cast a single batch of blades, the company was able to 3D print the blades in just three weeks.
Second, the 3D printed blades showcased a rejection rate of under 3% compared to rates of up to 30% for casted blades. This was achieved by making minimal changes to the original casting model and using 17-4 PH stainless steel material.
“We’ve also been able to reduce the cost per blade by around 40 to 45%,” added Klaus Notarbartolo. “That means cost savings for us and in turn for our customers. When you combine that with a reduction in product development time, higher efficiency and lower rejection rates, then the business case for additive really becomes attractive.”
In making the endoCupcut device, Endocon has worked with Weber-KP, a 3D printing service bureau specializing in metal AM. The Weber-KP team reportedly takes care of many aspects of the process, starting with data preparation and orientation on the build platform, to the printing and finally to extensive post-processing (including surface finishing, hardening and bead blasting).
Impressively, the 3D printed medical devices have demonstrated high performance properties, including good corrosion resistance and hardness levels. That is, rather than crack at 600 N, the 3D printed blades have demonstrated plastic deformation after 1.8 kN. In terms of hardness, Endocon reports 42+-2 HRC compared to 32 HRC using casting.
“Endocon’s ability to solve multiple challenges using additive is impressive example of how it can have a positive impact for smaller companies targeting the orthopedic industry,” said Stephan Zeidler, business development manager for medical at GE Additive. “What started with the need for a reduced time-to-market in terms of product development and flexible production of various shapes and sizes has resulted in a smart, innovative medical product that enhances patient outcomes. Moving the entire production process from casting to additive manufacturing was a logical step and that shift continues to provide inspiration for future projects.”
Presently, Endocon’s hip cup removal device is already being implemented by a number of medical professionals in Germany, who have seen positive outcomes in terms of reducing surgery times. In fact, Endocon reports that using its 3D printed blades, surgeons can cut surgery time down from an hour and a half to only three minutes.