Effects of collagen membrane application and cortical bone perforation on de novo bone formation in periosteal distraction: an experimental study in a rabbit calvaria

OBJECTIVES: The aim of the present study was to assess the impact of collagen membrane application and cortical bone perforations in periosteal distraction osteogenesis. STUDY DESIGN: A total of 32 New Zealand rabbits were randomized into four experimental groups, considering two treatment modalities. Calvarial bone was perforated or left intact (P+/-). In half the animals, the distraction mesh was covered with a collagen membrane (M+/-). All animals were subjected to a 7-day latency period and a 10-day distraction period. The samples were harvested after 4-week and 8-week consolidation periods and analyzed histologically and by means of micro-computed tomography. RESULTS: Primary, woven bone observed at the 4-week consolidation period was gradually replaced by lamellar bone at the 8-week consolidation period. Significant increase in bone volume was found in all groups (P < .001) and in bone mineral density in groups I (P-/M-; P < .001), III (P+/M-; P < .001), and IV (P+/M+; P = .013). Group III (P+/M-) showed significantly more new bone at the 8-week consolidation period compared with the other three groups (P = .001), with no differences observed in bone mineral density between groups at a given time-point. CONCLUSIONS: In the present model, cortical bone perforations have more impact on the osteogenic process compared with the application of a collagen membrane.