KLS Martin Group Uses LaserCUSING to 3D Print Patient-Specific Craniomaxillofacial Surgical Implants and Systems

Imagine looking in the mirror and not recognizing yourself…this can be an unfortunate reality for people with severe craniomaxillofacial (CMF) deformities or traumas. In addition to having one or more of their five senses not working properly, affected people can also be ridiculed or even shunned by the people around them; on top of the pain they’re already feeling due to the deformity, not fitting in with one’s peer group can often lead to depression. CMF surgery uses osteosynthesis and skull distraction to correct these deformities and injuries, and one of the leading providers of implants for CMF surgery is Karl Leibinger Medizintechnik. The company belongs to medical device company KLS Martin, which is headquartered in Germany, but revealed plans to construct its first US manufacturing facility in Florida last summer, close to its North American subsidiary KLS Martin LP.

About a year ago, KLS Martin partnered with 3D Systems to 3D print the final implant for young Grace Kabelenga’s complex surgery. Since 2013, KLS Martin’s patient-specific implants have been additively manufactured, based on fellow German company Concept Laser‘s patented LaserCUSING process, and one of its M2 cusing machines is on the floor at Karl Leibinger Medizintechnik. The company follows the same approach for all of its surgical instruments: instead of working out a standard solution, focus on the individual patient. In keeping with this philosophy, Frank Reinauer, the Head of Innovation and Production of Biomaterials at Karl Leibinger Medizintechnik, always uses 3D printing to manufacture patient-specific implants for these often complex CMF surgeries.

“We have of course long had our eye on the additive approach,” said Reinauer. “But we also had very precise notions of what the machine needed to be capable of. After the first decade of 3D metal printing, the time seemed to have come to get involved.”

Surgeons have to choose the right CMF implant for operations: conventionally manufactured implants can be made of plastic (polyether ether ketone, or PEEK, is often used), titanium mesh, or deep-drawn metal sheets, and also additively manufactured titanium implants. Titanium, which offers biocompatibility and high corrosion resistance, allows bone to grow, which makes it “the perfect material for implants in combination with lattice structures made by additive manufacturing.”

“From numerous aspects we view titanium as providing the benchmark for implant technology,” said Reinauer.

He continued, “But there is another very important aspect in favor of additively manufactured titanium implants: the patient-specific geometry and precision fit. Ultimately this means a high level of functionality.”

Some of the benefits of using titanium to 3D print patient-specific implants include:

• definable edege and surface texture ensure good bone ingrowth
• high strength
• quicker patient recovery
• elastic, and resistant to high temperature and corrosion
• functionality and aesthetics are positively affected by precision fit and freedom of geometry

KLS Martin is a specialist in the field of titanium osteosynthesis. It was determined, soon after KLS Martin adopted 3D metal printing, that laser melting was the way to go for this. Thanks to additive manufacturing, large-scaled reconstructions, with complex geometries, can be produced, and the geometric freedom of 3D printing makes for aesthetically pleasing results for patients.

“In craniomaxillofacial surgery, reconstructions of the skull (cranium), the upper or lower jaw and the nose in the midface are treated by surgeons – with the exception of the dental area, for which dentists are responsible,” explained Reinauer. “Internally we refer to ‘everything above the tie.’ Corrective methods are distraction and osteosynthesis. We often have to work with very complex and large-scale reconstructions which should also live up to a high aesthetic standard.”

The company is a global supplier of items necessary for CMF operations, like pins, plates, meshes, screws, lasers, implants, and distractors. When a bone “forgets” to grow, distraction osteogenesis encourages it to grow again. Karl Leibinger Medizintechnik also makes good use of a digital process chain: implants, distractors, and other parts, even large-scale ones, are quickly manufactured on its M2 cusing machine, which makes it possible to safely process reactive materials like titanium.

“The surgeon may of course also decide to opt for a solution in PEEK or for deep-drawn sheets from us,” said Reinauer. “A laser-melted solution, let’s say made of titanium, offers him the advantage of a biocompatible material which is also suitable for allergy sufferers. In addition, titanium has very high strength. Particularly with laser melting, we can tailor the construction very specifically to the patient’s anatomical structure, that is to say the optimum geometry, and incorporate the biological structure at the same time. We can define specific, including partial, surface roughnesses which help to ensure that the implant grows in well. Titanium, originally a material from the aerospace sector, has developed into a benchmark for medical technology. The material has set the standards in titanium osteosynthesis.”

More and more surgeons are utilizing these types of implants – Karl Leibinger Medizintechnik has delivered thousands all around the world. But it’s not as easy to get an implant from medical suppliers as just picking up the phone and calling an engineer. But, the company uses a system specifically designed to make the process easier for both sides.

“Engineers are not doctors and doctors are not engineers. But both worlds must talk to one another. We offer a transparent order handling system to enable this to happen. It is a web-based platform which can also be controlled via an APP in which we and the hospital side are in dialog and can see what and when something is happening. In addition to the patient-specific implants, anatomical models for optimum presurgical planning can also be requested on this site. It is often also necessary to cater for special requests in the construction, for example when removing a tumor that needs to be planned on a larger scale. We then also offer a complete implant kit which can be installed very quickly and precisely in an operation. Before making the decision to fabricate, the doctor sees a draft design and a price quotation. This means we are able to supply additively manufactured implants for an operation within a week. A patient-specific implant is a great gift, but it also requires a finely tuned process chain between the engineer and doctor through to the operation,” said Reinauer.

The doctors have a chance to see a first design draft, and a price quotation, before making their final decision to purchase the implant, which Karl Leibinger Medizintechnik engineers make using imaging data, from a provided MRI or CT scan, that’s sent to them by a radiologist. Thanks to this system, the company can build and send these 3D printed implants within a week, to the relief of the surgeons, and undoubtedly, the patients themselves. Discuss in the LaserCUSING forum at 3DPB.com.