The Present State and Future Implications of Patient-Specific Anatomy Models with 3D Printing

First results from the application of 3D models in clinical practice confirm the expectations for additive manufactured models in the medical field. The Hospital Dahme-Spreewald, in Germany, was one of the first hospitals that decided to use models created by a service provider, MMM GmbH (Medizinische Modellbau Manufaktur/Medical Model Manufactory).

“For a complex operation on the pelvis of the patient, the 3D fabricated model was optimal to test whether, as thought, the operation is possible,” explains Professor Dr. med. Michael Wich, an expert on trauma surgery at the Hospital Dahme-Spreewald.

The fact the there was an exact replica at a scale of 1:1 (life size model) made it possible to adjust implants prior to the surgery.

Medical imaging techniques and diagnostic procedures such as computed tomography (CT) for hard tissue (e.g., bone structures) and magnetic resonance imaging (MRI) or ultrasound scanning (US) for soft tissue (e.g., organs) have been established and improved for a long time in the medical field. Similar to the additive manufacturing process, those processes are based on a layer-wise representation method of bodies or body parts and it provides nearly all the required information to fabricate additive manufactured anatomical models. To create a model, the MRI or CT data of the patients are converted into a digital 3D model using a special software. The replica is printed using a 3D printer and finished by hand. The use of different materials provides an almost lifelike feel. This means that bone models are made of hard materials and organ models are made of flexible materials. It’s also possible to combine both characteristics in one model or to display foreign objects like implants. Thus, the models can be used as a realistic replica of the original and finished with the existing instruments in the operating room. The fabrication of an individual model is a complex, interdisciplinary process that requires the cooperation of physicians, radiologists, computer scientists and engineers.

In the case of a 27-year-old female patient it was necessary to print an individual 3D replica of the pelvis. Multiple fractures and previous surgeries made it necessary to have a detailed 3D printed model to plan the surgery and prepare the instruments and implants. The treatment was carried out successfully as planned and physician and patient spent about 20 minutes less in the operating room. Above all, the patient was able to leave the hospital after only 6 days.

Translucent pelvis with flexible spinal disc and implant

(photo credit: Materialise)

The benefit of patient-specific anatomy models lies primarily in the precise planning of complex medical procedures. This allows the surgeon to adapt implants and medical instruments to each unique situation. In addition, the communication with colleagues and patients is facilitated by an individual model. The use of these models contributes significantly to the better planning of surgeries, helps to shorten the duration of the operation and minimizes the burden on the patient. Economically, it supports to manage operations effectively and helps to avoid complications and follow-up procedures. As a result, it shortens hospital stays, and even amortizes the costs of the models.

It becomes clear, however, that the field of application is not only in the clinical field. Already today, anatomical digital models build the foundation in medical technology for the development of patient-specific instruments.

“We provide the company with the digital model of the patient, so that an individual instrument — e.g., a not quite straight extending endoscope — can be prepared,” says the CEO of MMM GmbH, Dr. Marcel Pfützner.

In the future, implants and instruments are individually tailored and manufactured to the patient based on patient-specific models. In summary, it is shown that additive manufacturing processes have the potential in certain areas of medicine to support the previous diagnosis and individualize the further treatment.

MMM GmbH, established in Germany near Berlin, is a service provider for the medical technology industry. With its AnatomX series the company specifically focuses on the development and production of patient-specific anatomical bone and organ models.

Thanks to Stephan Zeidler and MMM GmbH for this article.

Let us know what your thoughts relating to the use of 3D printed medical models are in the MMM GmbH 3D Printed Patient-Specific Medical Models forum thread at 3DPB.com.