Hematological Changes after Caprine Demineralized Bone Matrix Implantation in Ulnar Critical Defect of Rabbit Model.

Several animal models have been used in fracture healing and bone graft studies, but hematological responses are seldom reported. Therefore, the present study reported the hematological changes observed in rabbits that underwent xenografting of caprine demineralized bone matrix (CDBM).  Twenty-four (24) male rabbits (2.5 ± 0.5kg) were acquired for the purpose of this study and were randomly assigned to three groups: autologous bone graft (ABG), unfilled (NC), and caprine demineralized bone matrix (CDBM). Blood samples were collected through cardiac puncture under xylazine-ketamine anesthesia on day 0 (baseline), and on days 28 and 56 postsurgery and were analyzed manually within 2 hours of collection. Statistical analysis was performed using a two-way analysis of variance (ANOVA) with repeated measures, and a -value < 0.05 was considered significant.  There was an overall significant difference in the values of total white blood cell count (  = 0.0043), neutrophil count (  < 0.0001), monocyte count (  = 0.0184), red blood cell count (  = 0.003), hemoglobin concentration (  < 0.0001) and packed cell volume (  < 0.0001) across the days and the treatment groups. There was, however, no overall significant difference in lymphocyte count (  = 0.4923), basophil count (  = 0.4183), and eosinophil count (0.4806) within days.  Response to CDBM grafting in rabbits could, therefore, be said to be characterized by marked leukocytosis with neutrophilia, lymphocytosis, and monocytosis by day 28 of postgrafting. This could form the basis with which hematology can be used to monitor body response of bone graft animal models.