Periosteum and Bone Marrow Effects on Bone Regeneration: Histomorphometric Evaluation of a Lengthening Model in Rabbit | Insight Medical Publishing

Bone function requires a good repair system. The quantitative role of each healing component, mainly periosteum and bone marrow/endosteum and of their interactions is not clearly known. To evaluate more precisely the role of periosseous tissues in bone formation, we chose a bone lengthening model in rabbits. Nineteen purebred immature male New Zealand white rabbits were fitted with a femoral lateral external fixator and randomly assigned to 4 intervention groups: 1) Periosteum (PS) and bone marrow (BM) preservation; 2) PS preservation and BM destruction; 3) PS destruction and BM preservation; 4) PS and BM destruction. Animals were killed on day 30 and histology showed different bone regeneration modes. The most frequent ossification in the centre of the distraction gap was enchondral ossification. For bone formed between cortices only group 1 showed a difference (p=0.034). Density of the formed bone at the periosteal site showed a positive effect only with PS preservation, with an interaction of BM and PS. Density of group 4 was different from groups 1 (p=0.028), and 2 (p=0.001). No difference was present between groups at the endosteal sites. PS had a positive effect on the thickness of the formed bone at the periosteal site, with an interaction between PS and BM, but not at the endosteal site. A difference in thickness was noted between group 2 and 4 (p=0.018). Periosteum forms more bone and more likely to spread than bone marrow, but for restoration of the cortical wall, preservation of both shows optimal density results. Bone does not seem to form from surrounding tissues when both periosteum and bone marrow are destroyed.