REPAIR OF HUMAN SKULL DEFECTS USING OSTEOINDUCTIVE BONE ALLOIMPLANTS

To estimate the efficacy of cranioplasty in clinical practice, autolyz ed, antigen-extracted, allogenic (AAA) bone was prepared from cortical bones of human organ donors. AAA bone implants consisted of completel y demineralized bone powder, completely demineralized pliable bone chi ps, surface-demineralized bone chips with pliable crevices, surface-de mineralized rigid bone chips, or combinations thereof, 21 patients rec eived AAA bone cranioplasties and were followed-up for between 12 and 58 months (average: 29 months). No infection or rejection of any of th e AAA bone implants occurred. X-ray assessments as well as bone scinti graphies revealed osseous integration and remodelling of the AAA bone implants with minimal resorption, with the exception of completely dem ineralized AAA bone chips which showed partial resorption (2 cases). H owever, the partial resorption of completely demineralized AAA bone ch ips ceased after the implants had been remodelled. In 4 cases, the ost eosynthesis material was removed between 10 and 18 months after the cr anioplasty. In another case, a re-entry was necessary because of recur rence of an intracranial tumor, All of these five AAA bone reconstruct ions showed bleeding surfaces and osseous consolidations at the time o f re-entry. A bone biopsy taken from one of these cranioplasties showe d osteoinduction on the surface of the AAA bone implants. This first c linical review of cranial reconstructions using osteoinductive AAA bon e implants emphasizes the therapeutical application of AAA bone for cr anioplasty. Large AAA bone chips from human skull bones facilitate the reproduction of the skull's convexity especially when combined with p reoperative stereolithography-based planning.