Experimental Research On Repairing Rabbit Vertebral Of Bone Defect With The Compound Of Concentrated Autologous Bone Marrow Cells And Injectable Rebone Gu Tai

Objective:To Investigate the histological and biomechanical properties of the compound of concentrated autologous bone marrow cells and injectable Rebone Gu Tai, using a rabbit vertebral bone defect model.Methods:Forty-eight healthy New Zealand white rabbits were utilized in the present. Eeah group was divided into histological examination and biomechanical inspection.Three vertebral bone defects were surgically created randomly from L1-L7 in eath rabbit, and the defects were filled with concentrated autologous bone marrow cells/ CPC composite,CPC alone or left empty as a control. At 2, 4 and 8 weeks after surgery, general morphology and histological were observed. The average area of new bone tissue, the average gray level and the average optical density were measured using Motic medical image analysis system; Biomechanical properties were determined using the value of vertebral compressive strength and stiffness for all the experiment group , the normal control group and non-experimental hollow model .Result:1. General morphology when observed: incisions in all animals have varible edema but no infection. Specimens was removed, There was no significant tissue extravasation; 2. Histomorphological observation: after 2 weeks, 4 weeks and 8 weeks, experimental group showed less infiltration of inflammatory cells, fibrous connective tissue proliferation new bone formation, a good combination with the surrounding bone, CPC was gradually absorbed and degradated;The curtts of positive control group was similar to those of experimental group,however, osseointegration was poor andCPC degradation and absorption was slow; negative control group showed a large number of inflammatory cell infiltration fibrous connective tissue repair, hematoma, and osteoid formation, a rich blood supply. Using Motic medical image analysis system for measuring the average area of new bone tissue, the average gray level, the average optical density, multi-factor analysis of variance test showed the experimental group, compared with the positive control group, and negative control group (P<0.0001, P<0.0001); positive control group and negative control group (P<0.0001) at different time period in each group; 3. Biomechanical testing: In the average strength and stiffness, the normal vertebral body control group, the experimental group and the positive control group showed significant differcence when compared with non-experiment hollow vertebral model and negative control group (P<0.05) . There was no significant differcence among the normal vertebral body control group and experimental group and positive control group (P>0.05); negative control group and non-experiment hollow vertebral model group showed significant differcence (P<0.05). at different time points, the average strength of the experimental group, the positive and negative control group had a increase trendy; the average stiffness of the experimental group and the negative control group had the increase trend, The average stiffness of the positive control group during the period did not change significantly; repeated measure analysis of variance showed strength and stiffness of the experimental group were stronger than those of the positive control group and negative control group at different time period(P <0.05, P<0.05); those of positive control group were stronger than those of negative control group(P<0.05); the same group at different times, strength and stiffness showed significant differcence in each time point (P<0.05)except that the stiffness of the positive control group showed no significant differcence ( P>0.05) .Inclusion: Concentrated autologous bone marrow cells/ CPC composite can sustain bone induction, enhance bone formation and speed CPC degradation which is compatible with biomechanican after bone formation; It can restore strength and stiffness which suggested that Concentrated autologous bone marrow cells/ CPC is a kind of indeed bone filling material for bone defect after thoracolumbar fractures, especially for Kyphoplasty after osteoporotic vertebral compression fractures.