Objective To study the vascularization of the compositeof bone morphogenetic protein 2 (BMP-2) gene transfected marrow mesenchymal stem cells (MSCs) and biodegradable scaffolds in repairing bone defect. Methods Adenovirus vector carrying BMP-2 (Ad-BMP-2) gene transfected MSCs and gene modified tissue engineered bone was constructed. The 1.5 cm radial defect models were made on 60 rabbits, which were evenly divided into 4 groups randomly(n=15, 30 sides). Different materials were used in 4 groups: Ad-BMP-2 transfected MSCs plus PLA/PCL (group A), AdLacz transfected MSCs plus PLA/PCL (group B), MSCs plus PLA/PCL (group C) and only PLA/PCL scaffolds (group D). The X-ray, capillary vessel ink infusion, histology, TEM, VEGF expression and microvacular density counting(MVD) were made 4, 8, and 12 weeks after operation. Results In group A after 4 weeks, foliated formed bones image was observed in the transplanted bones, new vessels grew into the bones, the pores of scaffolds were filled with cartilage callus, osteoblasts with active function grew around the microvessels, and VEGF expression and the number of microvessels were significantly superior to those of other groups, showing statistically significant difference (Plt;0.01); after 8 weeks, increasingly more new bones grew in the transplanted bones, microvessels distended and connected with each other, cartilage callus changed into trabecular bones; after 12 weeks, lamellar bone became successive, marrow cavity recanalized, microvessels showed orderly longitudinal arrangement. In groups B and C, the capability of bone formation was weak, the regeneration of blood vessels was slow, after 12 weeks, defects were mostly repaired, microvessels grew among the new trabecular bones. In group D, few new vessels were observed at each time, after 12 weeks, broken ends became hardened, the defectedarea was filled with fibrous tissue. Conclusion BMP-2 gene therapy, by -upregulating VEGF expression, indirectly induces vascularization ofgrafts,promotes the living of seed cells, and thus accelerates new bone formation.
The causes of development of 56 cases of bone defects from firearm injuries of extremities were analyzed, and the advantages of transfer of vascularized iliac bone graft with deep iliac circumflex vessels in 28 cases and the indications of transfer of vascularked fibular bone graft with fibular vessel in 15 cases and the exporiences in 9 cases from the methed of transter of seapula-cutaneous composite graft were summarized. It was emphatically pointed out that the half-circle typo externa fixators had its unique advantages in the treatment of the bone defects of long bones of extremities from firearm injuries. It would enentually become the method of priority for the treatment of fractures, nonunion of fractures and bone defects of extremities from firearm injuries.
Abstract An experiment was carried out to investigate the possibility of the establishment of an osteoblasts bank which could supply osteoblasts in repairing bone defect. Osteoblasts were isolated from thetibial periosteum of eight New-Zealand rabbits and cultured in votro. A bone defect, 1.5cm in length was made in both radii of each of the 8 rabbits. The cultivated osteoblasts, gelfoam as a carrier were randomly implanted into the defects of the radii of rabbits. Accordingly, the contralateral radial defects wereimplanted with gelfoam absorbed with the Hanks solution as control. The healing of bone defects was evaluated by roentgenographic examination at 2, 4, 8 and 12 weeks after operation, respectively. It was shown that the implanted cells had osteogenetic capability and could be possible to promote healing of the bone defects. It was suggested that further study needed to be carried out in this field.
Abstract To examine the effects of porous tricalcium phosphate (TCP) combined with autogenous red bone marrow (BM) in therepar of bone defects, 21 cases of bone defects were implanted with the above prepared composite material, 17 cases had benign or low-grade malignant tumors and 4cases had old fractures. Serial X-ray films were taken after surgery. The results showed that new bone formation was seen between the interface of the implantand surrounding host bone after 6 weeks, and osseous union developed after 12 weeks. Evident osteogenesis in all patients was observed after a follow-up for 1～3 years. TCP-BM is both osteoconductive and osteoinductive. Its function was similar to the fresh autogenous cancellous bone graft and TCP-BM had the potencyof promoting the repair of osseous defect. It was suggested that TCP-BM might be an ideal material for treating bone defects.
There were several methods, such as free single and folded fibulae autograft, composed tissue autograft, however, it is still very difficult to repair long segment bone defect. In December 1995, we used free juxtaposed bilateral fibulae autograft to repair an 8 cm of femoral bone defect in a 4 years old child in success. The key procedure is to strip a portion of the neighboring periosteal sleeve of juxtaposed fibulae to make bare of the opposite sides of the bone shafts, suture the opposite periosteal sleeves, keep the nutrient arteries, and reconstruct the blood circulation of both fibular by anastomosis of the distal ends of one fibular artery and vein to the proximal ends of the other fibular artery and vein, and anastomosis of the proximal ends of the fibular artery and vein to lateral circumflex artery and vein. After 22 months follow up, the two shafts of juxtaposed fibulae fused into one new bone shaft. The diameter of the new bone shaft was nearly the same as the diameter of the femur. There was only one medullary cavity, and it connected to the medullary cavity of femur. This method also cold be used to repair other long segment bone defect.
ObjectiveTo investigate the reconstruction mode selection of acetabular bone defect and the effect on the acetabular cup position in cementless total hip arthroplasty (THA). MethodsA retrospective analysis was made on the clinical data of 78 patients (78 hips) with acetabular bone defect according to the selection criteria who underwent THA between February 2008 and February 2014. In 39 cases having acetabular posterosuperior bone defect with defect area less than 30%, impaction bone grafting was performed (group A); in 24 cases having acetabular posterosuperior bone defect with defect area of 30%-50%, structural bone or tantalum block grafting was performed (group B); in 10 cases having acetabular medial wall bone defect with defect area less than 30%, impaction bone grafting was performed (group C); and in 5 cases having acetabular medial wall bone defect with defect area of 30%-50%, titanium mesh combined with impaction bone grafting was performed (group D). There was no significant difference in gender, age, and side between groups A and B, and between groups C and D (P>0.05). The acetabular abduction angle, anteversion, the horizontal and vertical distances of actual and true rotation center after operation were compared. ResultsThe patients were followed up 7-25 months. Prosthesis loosening occurred in 2 cases of group A, sciatic nerve injury and hip joint dislocation in 1 case of group B, respectively. At immediate after operation and last follow-up, there was no significant differences in the horizontal or vertical distance of actual and the true rotation center between groups A and B (P>0.05); significant difference was found in the horizontal distance between groups C and D (P<0.05), but no significant difference in the vertical distance (P>0.05). Difference was statistically significant in the acetabular abduction angle and anteversion between groups A and B (P<0.05), but difference was not significant between groups C and D (P>0.05). ConclusionIn patients with acetabular posterosuperior bone defect, reconstruction methods will have effect on acetabular abduction and anteversion; early acetabulum prosthesis loosening may be associated with too large acetabular abduction angle and inappropriate reconstruction methods. In patients with acetabular medial wall bone defect, the vertical distances of rotation center will shift upward in varying degrees, and reconstruction methods have effect on the horizontal distances of rotation center.
In the study of repair of massive bone defect with free vascularized fibula graft, 13 cases were reported, in which traumatic defect in 7 cases, segmental resection of bone from tumors in 5 cases and osteomylitis in 1 cases. They all were treated successfully with vascularized fibular graft. After a follow-up of 6 months to 7 year, bone healing was observed with satisfactory and rehabilitation of functions. In one case, fatigued fracture occured twice due to early walking. It was concluded that free vascularized fibular graft was very helpful in the repair of massive bone defect, but prolonged external fixation after operation might be important to prevent fractur of grafted bone.
Repair of bone defect by compound of bone morphogenic protein (BMP) and its prior bone matrix gelatin (BMG) was compared with repair by BMP with hydroxyapatite(HA). The results showed that the BMP/BMG group was found fibrous callus in the bone defect in 4th week. In 8th week a large quantity of osseos trabecula was found. In 12th week the BMP was absorbed completely and was replaced by newly formed bone. In 16th week the recanalization appeared in the bone cavity. While in the BMP/HA group, although the fibrous callus was appeared in the 4th and 8th weeks, the HA was not absorbed. In the 12th and 16th weeks the change was similar to that in the 8th week and no recanalization of bone marrow cavity. It was suggested the BMP/BMG compound might be an ideal material to repair the bone defect.
Objective To evaluate the osteogenesis of three bio-bone derived materials in repairing segmental bone defects. Methods Sixty Japanese rabbits were made 10 mm radius segmental defects and divided into 5 groups(groups A, B, C ,D and E,n=12). Composite fully deproteinised bone(CFDB, group A), partially deproteinised bone(PDPB, group B), partially decalcified bone(PDCB, group C), autogenous iliac bone graft(group D) and no implant(group E) were implanted into the radius segmental bone defects of rabbits. The specimens were examined after 4, 8, 12 and 24 weeks; the osteogenesis was evaluated through X-ray radiograph and undecalcified solid tissue histological examination.Results The border between the material and host’s bone was distinct after 4 weeks and blurred after 8 weeks; the density of partial edge of the material was similar to that of radii after 12 weeks. The medullary cavity of bone reopened in group B; the density of most defect area was similar to that of the host bone and there was a few high density shadow in group C; the density of most defect area was higher than that of host bone in group A after 24 weeks. There was no significant difference in radiograph scoring between groups A, B and C after 4 weeks and 8 weeks(P＞0.05); the scores of group B and C were higher than that of group A after 12 weeks(P＜0.05); and the scores were arranged as follow: group Dgt;group Bgt; group Cgt;group A after24 weeks(P＜0.05). Bone callusgrew toward defect area and new bone adhered to the material after 4 weeks and 8 weeks; more new bone formed, and the materials were absorbed and degraded with time. The quantity of bone formation was more in group D than in group B andin group B than in group C and in group C than in group A after 24 weeks(P＜0.05).Conclusion PDPB had good osteogenesis in repairing the segmental bone defect, PDCB was inferior to it, both PDPB and PDCB are fit to repair segmental bone defect. Both of them were inferior to autogenous bone.
Objective To study the effect of vascular endothelial cell growth factor (VEGF) on repair of bone defect with cortical bone allograft. Methods Forty five New Zealand white rabbits, weighted 2.5-3.0 kg, were made bone defect model of 1.5 cm in length in the bilateral radii and then were randomly divided into 3groups. The defect was repaired with only cortical bone allograft in the control group, with the cortical bone allograft and local injection of human recombinantVEGF in the experimental group, and with the cortical bone allograft and abdominal injection of VEGF PAb3 in the antagonist group. Roentgenography, immunohistochemical staining and tetracycline labelling were carried out to evaluate the reparative results 1, 3, 5, 8 and 16 weeks after operation. Results Immunohistochemical staining results showed that a great deal of blood vessels formed in the experimental group, and the number of blood vessels increased gradually with the time and reached the highest value at the 8th week. Tetracyclinelabelling showed the same result.The best results in callus formation, ossification rate and count of microvascular density were shown in the experimental group, while those in the control group were significantly better than those in the antagonist group (Plt;0.05),but there was no significant difference between the experimental group and the control group at the 8th week and the 16th week (Pgt;0.05). Conclusion VEGF can accelerates the bone formation and angiogenesis in the bone allografts, thus it can promote the repair of bone defects.