A novel 3D‐printed patient‐specific limb‐sparing radial endoprosthesis for treatment of primary osteosarcoma in a Great Dane

OBJECTIVE: To describe a novel titanium three-dimensional-printed patient-specific radial endoprosthesis (3D-PSE) for the successful treatment of a primary osteosarcoma in a 7-year-old female Great Dane. STUDY DESIGN: Case report. METHODS: The dog presented with a 10-day history of swelling of the right distal radius. Computed tomography (CT) revealed an osteolytic lesion involving the distal metaphysis and diaphysis of the radius which was highly suspicious for an osteosarcoma (OSA). Thoracic CT showed no metastases. CT data was used to create a virtual 3D-model of the affected limb within computer-aided design software which was used for virtual osteotomy planning and the design of the 3D-PSE. During surgery 3D-printed patient-specific guides were used to execute osteotomies. The 3D-PSE comprised plate sections for attachment to the proximal radius and metacarpals 3, 4 and 5, and an integrated cage for bone graft to replace the radial defect. Histopathology demonstrated OSA, and postoperative adjuvant chemotherapy comprised five IV infusions of carboplatin every 3 weeks. The Liverpool Osteoarthritis in Dogs (LOAD) questionnaires were completed by the owner preoperatively and for each follow-up until the 6-month re-evaluation. RESULTS: No complications occurred intra-/post- or perioperatively. LOAD scores preoperatively, and at 6, 12 and 24 weeks postoperatively were 19, 13, 11 and 10. Ten months after surgery thoracic radiographs revealed multiple pulmonary metastases, but the dog remained asymptomatic for a further 6 weeks when progressive dyspnea and lethargy prompted euthanasia. Lameness was absent at that time. CONCLUSION: The described novel 3D-PSE provided an effective function-preserving solution as part of a multimodal treatment of a giant breed dog with OSA of the distal radius.