3D Printed Medical Models for Hip Surgeries Prove to Be Helpful but Expensive

Researchers explore the efficacy of 3D printed pre-operative models for hip surgeries in the recently published ‘Advantages and disadvantages of 3D printing for pre-operative planning of revision hip surgery.’ Total hip arthroplasties (THA) are extremely common today, treating patients who may be suffering from arthritis of the hip; however, the procedure requires a skilled surgeon and staff, along with comprehensive pre-planning.

For this research study, the team of scientists 3D printed a life-size model using a CT scan from a 66-year-old male with coxarthrosis, and one arthroplasty in his background already for the left side, in February of 2017. The CT scan and the X-ray for his right side showed both a pelvic defect and severe acetabular defect.

The CT scan was imported into 3D Slicer to effect differentiation of the pelvis and the hip from the soft tissue. The researchers stated that they segmented the digital image of the pelvis by deleting pixels and isolating the pelvis. They then saved the highlighted data for 3D printing on a Formlabs 2.

“The 3D model enabled visual assessment of the complex acetabular deformity. Given the complexity of our case, the hemipelvis model allowed a life-size anatomical representation of the operative field,” stated the researchers.

(a) CT scan of the defect. (b) CT scan of the defect.

Preoperative radiograph demonstrating large acetabular defect with screw penetration.

The surgery was uneventful, with the research team explaining that a trabecular metal cup was implanted in the male patient, and the femur was rebuilt with a cementless Alloclassic stem. Surgeons reported a ‘satisfactory’ outcome for the surgery, with post-operative rehabilitation beginning right away, and then the patient bearing partial weight on the healing hip and leg area for a total of six weeks.

In using the 3D printed model for pre-operative planning, the orthopedic team was able to hold it, rotate it, and view it before undertaking the procedure.

“Our model improved diagnostic accuracy and helped us predetermine the implant and the implant size,” concluded the researchers. “Complex acetabular deformity reconstruction was planned and managed efficiently with good surgical outcome.”

There were some concerns regarding 3D printing of the medical models however, as the researchers found it to be demanding, requiring a somewhat advanced skill set. They also found the process to be ‘a time extended process,’ with each model taking around 12 hours to print. And in these cases, because the 3D template must also be presented with a CT scan each time, the process is more expensive overall and means extra exposure to radiation for the patient.

3D printed medical models are changing the face of education, training, and planning around the world in clinical settings and operating rooms. Today, these models mean that doctors are able to deal with bone fractures more comprehensively, give better preoperative education to aneurysm patients, and even use such devices to reconstruct anatomy like the eye socket.

What do you think of this news? Let us know your thoughts; join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

a) Life-size 3D model (anterior vi6ew). (b) Life-size 3 model (posterior view).