Hydroxyapatite cement (BoneSource TM) for repair of critical sized calvarian defects—an experimental study

Aim: In an experimental study the hydroxyapatite cement BoneSource TM was tested for the ability in relation to the defect size and for its resorption properties. Material and methods: In an animal study, BoneSource TM was applied to repair bicortical defects of different sizes in frontal bones of six Goettingen minipigs. The area was evaluated radiographically and histologically 12, 18 and 40 weeks postoperatively. Results: After 40 weeks approximately 90% of the hydroxyapatite cement had been resorbed and replaced with bone. After 12 weeks, approximately 30% had been degraded, and 40% after 18 weeks. In small bone defects, the mucosa of the frontal sinus lined the bone substitute (BoneSource TM). In the reconstruction of large areas, a membrane was used to stabilize the material. Despite this membranous support, BoneSource TM material prolapsed into the frontal sinus. Discussion: Hydroxyapatite cement is for the repair of bone defects. It can be moulded to shape the reconstruction. Its use is limited by the defect size and the need for a dry bed. Conclusion: BoneSource TM is well suited to repair small defects with proven high biocompatibility. However, in large defects, the material is not sufficiently stable.