ABM/P-15-enhanced bone graft in oncologic cervical spine reconstruction: two case reports and narrative discussion

Bone consolidation in musculoskeletal oncology is challenging after pathological fracture, radiotherapy, repeated surgery, extensive reconstruction, or compromised vascularity. Successful healing also requires segmental mechanical stability. Anorganic bone mineral/P-15 (ABM/P-15) bone grafts provide an osteoconductive mineral scaffold with a synthetic collagen-mimetic peptide surface, but their use in oncologic cervical spine reconstruction remains sparsely described.

At the McGill University Health Centre, a tertiary referral center, we report two complex cervical oncologic reconstructions in which ABM/P-15 was used as one component of multicomponent fusion constructs. A young adult male with metastatic solitary fibrous tumor, prior radiotherapy, upper cervical nonunion, and pathologic fracture underwent revision occiput-to-T2 fusion with local autograft and ABM/P-15. A young adult female with recurrent cervical chordoma after prior resection and proton-beam radiotherapy underwent combined anterior and posterior tumor resection, instrumentation, and fibular graft reconstruction augmented with ABM/P-15. In both cases, rigid reconstruction plus adjunctive grafting was followed by CT and radiographic evidence of bridging bone or host-graft incorporation without implant loosening or pseudoarthrosis at approximately 12 months. Standardized Visual Analog Scale (VAS)/Numeric Rating Scale (NRS) and Neck Disability Index (NDI) scores were not collected.

These two cases document radiographic fusion after complex oncologic cervical reconstructions in which ABM/P-15 was used as an adjunct. The perceived rationale was to provide an osteoconductive, collagen-mimetic surface in compromised host biology, but these cases do not establish that ABM/P-15 independently caused fusion or improved oncologic safety. The findings should be interpreted as descriptive and hypothesis-generating.