Saving Jojo's Leg with Pre-Surgical Planning in 3D
A five-year-old boy named Jojo from a village near Munich was diagnosed with a rare malignant tumor called Ewing`s Sarcoma. Usually found in the diaphysis (middle part) of long bones Jojo`s tumor was located in the distal part of his left femur and very close to the growth plate. Since tumor-endoprostheses are not available for such young children due to their small anatomical dimensions, an amputation or rotation plasty has to be performed in these cases.
But the surgeons in Munich aimed at avoiding to amputate the leg of this five-year-old boy. Therefore they developed a surgical plan in order to resect the tumor with wide margins and reconstruct the bony defect with biological material (a combination of his own fibula and a donor bone) but without harming the adjacent growth plate. To realize this courageous and complicated plan the surgeons from Munich contacted Materialise.
Firstly, CT and MRI scans were uploaded to Materialise Mimics and a digital 3D model of his femur was created based on the uploaded radiographic data. Working closely together with Dr. Ulrich Lenze and Dr. Carolin Knebel, both surgeons at the Orthopedic Department of the Klinikum rechts der Isar in Munich, Materialise clinical engineer Antoon Dierckx helped to plan the resection of the tumor as well as the subsequent reconstruction with donor bone (allograft) all in 3D. Since young donors of allografts are likewise very rare, one further tricky part was to find a donor bone which meets the anatomical preconditions and fits to the dimensions of Jojo`s bone. Therefore, the surgeons were finally forced to use the humerus of an adult donor, two of them being provided by the German Institute for Cell and Tissue Replacement (DIZG). By use of a CT-scan of the donor bone and the digital Materialise surgical planning software it became obvious that only one of them would have a nearly perfect fit onto the patient`s bone
Afterwards, patient-specific resection guides were designed which allow for a precise resection of the affected bone segment according to the surgeon`s specifications. In this special case, an individualized 3D-printed titanium plate was manufactured, too, which was used to ensure a stable osteosynthesis of the allograft and the remaining local bone.
The operation lasted about 8 hours. During that time Jojo`s parents anxiously did their best to pass the time while their son was being operated. The efforts of the surgeons were rewarded: the operation was a success. The head of the surgical team - Professor von Eisenhart-Rothe – concluded, that the tumor was entirely resected and the surgeons were able to preserve the leg. If everything goes to plan and no complications occur, he will have the chance to make a nearly full recovery and use his leg without major restrictions.