Researchers at Skane University Hospital in Sweden have collaborated with 3D printing company Materialise to put teenager Fanny Fellesen back on her feet with a new 3D printed hip implant.
Fanny Fellesen

Fellesen, a Swedish 16-year-old with neurofibromatosis, a congenital disease also known as “Von Recklinghausen’s disease,” has coped with severe hip pain her entire life. A skeletal deformation of the left hip, along with a neurofibroma that devastated her pelvis, meant a great deal of pain and difficulty for the teenager.

In 2010, doctors surgically removed Fellesen’s neurofibroma, but after suffering a femur fracture a few months later, her situation worsened. At the time, Fellesen was left with no other option but home schooling, as for two years she was unable to physically attend classes. Doctors believed that Fellesen would require a wheelchair for the rest of her life.
Enter Professor Rydholm from Skane University Hospital in Lund, Sweden. In 2012, Rydholm contacted Mobelife, a subsidiary of Belgian company Materialise focused on medical 3D printing. The Mobelife team of engineers set to work designing a customized acetabular implant for Fellesen.
Using Mimics software, specialists imported and segmented a CT scan of Fellesen’s hip in order to reconstruct the defective area and examine the pre-operative situation. By way of anatomical templates, physicians were able to conduct a surgical planning directly based on the patient’s unique anatomy. This customized process involved placing landmark points, which were then used to determine the position of the acetabular cup and flanges and secure them in position.
virtual design of tri-flange customized cup
A customized implant was designed that matched the anatomy of the patient’s hip, allowing for an optimized fit. For Fellesen’s procedure, the Mobelife team used 3-matic, a medical 3D printing software that allows users to work directly on triangulated surfaces. Patient-specific flanges were designed, and the screws’ location was determined. In order to support the screws, Fellesen’s bone quality was analyzed via the grey values of the CT data in Mimics. Additionally, the Mobelife team performed a Finite Element Analysis (FEA) to confirm that the implant and bone assemblage would withstand the many motions and stresses of the hip joint. A surgeon verified the final design, which was then exported for 3D printing. LayerWise was used to 3D print the “triflanged” cup in titanium.
FEA simulation of the triflange cup
After the hip implant was delivered to the hospital and surgically attached, Fellesen reported almost immediately that she was, remarkably, pain-free. Within only a few months, the teenager was able to walk, replacing her wheelchair with a crutch. Currently, about a year and a half after her surgery, Fellesen is attending school again, walking entirely without crutches.
Belgian-based 3D printing company Materialise was established in 1990. After closely collaborating with partner Mobelife for several years, the two companies became fully integrated under the Materialise brand name in March 2016. To date, Fellesen’s case has proven to be one of Materialise’s most successful medical 3D printing solutions.