Abstract
This study presents the mid-term outcomes of a novel "biological prosthesis" for pediatric humerus reconstruction after major bone tumor removal. This approach involves a hollow 3D-printed titanium custom-made prosthesis combined with bone grafting. The primary aim was to preserve and revitalize the unaffected autologous proximal or distal humeral stump. Between 2017 and 2021, we treated five pediatric patients (mean age 11.2 years; range 7-17) with humeral bone sarcomas. A one-stage surgical procedure involved tumor resection and implanting a hollow 3D-printed custom-made prosthesis. In two cases, we preserved the proximal humerus; in two, the distal part; and in one, both. Graft materials included homologous bone chips in three cases and free vascularized fibular grafts in two cases. All patients were clinically and radiographically assessed after a mean follow-up of 32.2 months (range of 14-68). No significant complications were observed, and no implant revisions were needed. Osseointegration was evident in all cases within eight months post-surgery; vascular support for the remaining autologous stump was demonstrated in all cases. Our hollow 3D-printed custom-made prosthesis and bone grafting offer the potential for partial or complete articular surface preservation. This approach encourages revascularization of the epiphysis, leading to satisfactory outcomes in humerus reconstruction within the pediatric population.