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.
OBJECTIVE: To study the effect of platelet-rich plasma in the repair of bone defect. METHODS: Segmental bone defects of 1 cm were created in the mid-upper part of bilateral radius of 24 New Zealand white rabbits. One side was randomly chosen as the experimental side, which was filled with artificial bone with platelet-rich plasma (PRP). The other side filled with artificial bone without PRP as the control. After 2, 4, 8 and 12 weeks of implantation, the gross, radiological, histological observations, and computer graphic analysis were performed to investigate the bone healing of the defect in both sides. RESULTS: Two weeks after operation, new bone and fibrous tissue formation in both the experimental and the control sides were observed only in the areas adjacent to the cut ends of the host bone, but the amount of new tissue in the experimental side was much more than that in the control side. In the 4th and 8th weeks, the surface of the artificial bone was covered with a large amount of new bones, the artificial bone was bridged tightly with the host bone by callus in the experimental side, while new bone was limited mainly in the cut ends and was less mature in the control side. In the 12th weeks, bone defects were entirely healed in the experimental side, which were covered completely with cortical bone, while new bone formation was only observed in the ends of artificial bone and there were not continuous bone callus on the surface in the control side. CONCLUSION: Artificial bone with PRP is effective in the repair of segmental bone defects, and PRP could improve the healing of bone defect.
Objective To study the effect of direct bone morphogenetic protein 2 (BMP-2) gene therapy mediated by adenovirus on repairing bone defect. Methods The radial defect models were made on 60 rabbits, which were evenly divided into 4 groups randomly. The 4 groups were treated with different materials: group A, adenovirus carrying BMP-2 gene (AdBMP-2) plus bovine cancellous bone (BCB); group B, reconstructed BMP-2 plus BCB; group C, AdLacz plus BCB; and group D, only BCB scaffolds. The X-ray, histological examination, biomechanics analysis, and immunohistochemical staining were made 4, 8, and 12 weeks after the operation. Results Group A gained better effect in the volume of new bones, the anti-bending intensity of the healing bone, and the expression of BMP-2 than those of group B. The defect in group A was healed. No new bones were observed in group C and group D. Conclusion Direct BMP-2 gene therapy is easy to perform and has veryb osteoinduction ability. It is a good method to repair segmental bone defects.
Objective To explore the methods of repairing cartilagedefects and to introduce the clinical experience with the autologous osteochondral transplantation. Methods Twenty-five patients with chondral and osteochondral defects of the weight-bearing surfaces were treated by the autologous osteochondral transplantation for the repair of the chondral and osteochondral defects of the unweightbearing surfaces under arthroscope. According to the shape of the defects, the different dimensions of the osteochondral autograft were selected. All the patients began the training of the continuous passive motion after operation. Six weeks after operation, the patients began to walk in the weightbearing habitus. However, in the control group, another 25 patients were retrospectively analyzed, who had chondral and osteochondral defects of the weight-bearing surfaces but were treated only by the cleaning and drilling procedures. The scores evaluated bythe Brittberg-Peterson scoring scale of the 2 group were 98.65±9.87 and 96.98±8.94 respectively. Results The follow-upfor 3-24 months after operation revealed that the treated knee joint had a goodmotion extent. The pain was obviously alleviated. Based on the longitudinal study with the three-dimensional spoiled magnetic resonance imaging (MRI), the signal intensity of the repaired tissues approached to the normal condition. The scores evaluated by the Brittberg-Peterson scoring scale were almost zero 3 monthsafter operation in the experimental group, and the scores were 58.48±6.98 inthe control group. There were significant differences between the experimental group and the control group(P＜0.01). Conclusion Autologous osteochondral transplanation under arthroscope is a good curative method for the cartilage defects, with advantages of minimal invasiveness and avoidanceofrejections resulting from allografts. However, its long-term effect needs to befurther studied. The conventional therapies including cleaning and drilling are useful in alleviating the symptoms.
It is one of the difficult clinical problems to repair the large bone defect created by excision of benign tumors and to rebuilt the bone shelf. On the basis of the animal experiment, we excised thoroughly the effected bone subperiosteally and repaired the bone defect by fibula without its periosteum of other materials. The bone framework was successfully reconstracted. From Jan. 1984 to Dec. 1992, a series of seven cases were treated accordingly. The patients were followed up for 1 to 9 years. The skeletal framework in each was rebuilt rigidly. There was no recurrence and the functions of the extremity was recovered. In part of thesubperiosteum of fibula supplier bave regeneration of a new fibula with normal size at the site where the fibula was excised subperiosteally.
Since 1979, 13 different types of vascularized bone or periosteal flaps were used to repair bone defects following resection of skeletal neoplasms in 109 cases. The result was satisfactory. In this article, the main points in discussion werethe operative indication, how to design the flap and the technique used to repair the defect.
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.
Objective To evaluate the clinical effect of repair of massive bone defect in tibia by vascularized fibula grafting of either sides. Methods Twenty-four cases of massive bone defect in tibia, among which 14 cases were repaired by vascularized fibula grafting of the other side and another 10 cases were repaired by those of the same side, from 1987 to 1997 were followed up for 3 to 13 years; the functions of the operated limbs were evaluated according to Enneking Score System, and the outcome of the fibula grafts were assessed by radiographic examination with reference to the standard established by International Symposium onLimb Salvage. Results The average recover rate of the operated limbs in those repaired by the other side grafting was 80.7%, and the average healing period ofthe fibula graft was 14 weeks with fracture of the graft in one case which madethe operated lower limb shorten for about 2.5 cm; the fibula grafts were observed thickened in 43 weeks, on average, and the patients could walk independently without a crutch. While in those repaired by the same side grafting, the averagerecover rate of the operated limbs was 68.3%, the average healing period of thefibula graft was 17 weeks with fracture of the graft in 3 cases, in 2 of which the lower limbs were shortened for 2 cm and 4 cm respectively, and in the third one infection occurred and amputation was performed finally; the fibula grafts were observed thickened in 49 weeks, on average, which made it available for the patients to walk without a crutch. All of the data showed that there was a significant difference statistically between the differently treated cases. Conclusion It’s a good choice to repair massive bone defect in tibia by vascularized fibula grafting, and the vascularized fibula graft from the other side could promote the bone healing and accelerate the recover of the function of the operated lower limb.