Case report on metastatic pelvic bone tumor treated with frozen autograft by liquid nitrogen

Introduction and importance: Frozen autograft recycling has been used for biological reconstruction of bone defects following tumor excision, more commonly in extremities. We report on the histological outcome of a pelvic recycled frozen autograft. Case presentation: We investigated the pelvic frozen autograft removed in 2 years and 8 months after surgery because of soft tissue recurrence in pelvic floor. The autograft bone showed no evidence of revitalization and was non-viable with patchy inflammation, and no residual tumor. There was only fibrous union but the autograft bone remained mechanically stable. Clinical discussion: We confirmed the clearance of tumor cells with the treatment with liquid nitrogen. The union at the host-graft junction might be affected by the previous radiotherapy, the presence of infection, the small contact area limited by the anatomy, and the inadequate compression across the osteotomy interface with the fixation. Conclusion: Frozen autograft treated by liquid nitrogen can be used safely for biological reconstructions after pelvic tumor excision. (C) 2021 The Authors. Published by Elsevier Ltd on behalf of lIS Publishing Group Ltd.