We have also invited certain notable guests to share their expertise in the field of 3D printing and its future applications.

Rok Vojković, MD, Borut Pompe, MD, PhD
Department of Orthopaedic Surgery, University Medical Center, Ljubljana, Slovenia
Preoperative planning of revision total hip arthroplasty with a 3D printed hemipelvis model in juvenile idiopathic arthritis

We present a clinical case report of a 31-year old male patient with juvenile idiopathic arthritis scheduled for bilateral revision total hip arthroplasty due to component loosening after roughly 15 years. The challenge of revision being mainly the extensive bone defects in the acetabula, we began to search for the best way to plan the procedure. Based on computed tomography scans of the patient’s hips and pelvis, mechanical engineers produced a 3D printed model of the patient’s left hemipelvis. We used the model to plan the left-sided revision outside of the operating room using real instruments and implants, determining the best possible type and size of the acetabular component. We subsequently performed the actual surgical procedure on the patient using the preoperatively chosen posterior acetabular wall augment (TMARS, Zimmer Biomet) implant, which fit perfectly intraoperatively, and performs well postoperatively, as documented by clinical follow-ups. The right-sided revision is scheduled in the near future and it will be planned in the same manner. We want to present that 3D printing is a helpful tool for better planning of the revision total hip arthroplasty in complex cases.