Objective To investigate the effect of repairing bone defect with tissue engineered bone seeded with the autologous red bone marrow (ARBM) and wrapped by the pedicled fascial flap and provide experimental foundation for cl inicalappl ication. Methods Thirty-two New Zealand white rabbits (male and/or female) aged 4-5 months old and weighing2.0-2.5 kg were used to make the experimental model of bilateral 2 cm defect of the long bone and the periosteum in the radius. The tissue engineered bone was prepared by seeding the ARBM obtained from the rabbits on the osteoinductive absorbing material containing BMP. The left side of the experimental model underwent the implantation of autologous tissue engineered bone serving as the control group (group A). While the right side was designed as the experimental group (group B), one 5 cm × 3 cm fascial flap pedicled on the nameless blood vessel along with its capillary network adjacent to the bone defect was prepared using microsurgical technology, and the autologous tissue engineered bone wrapped by the fascial flap was used to fill the bone defect. At 4, 8, 12, and 16 weeks after operation, X-ray exam, absorbance (A) value test, gross morphology and histology observation, morphology quantitative analysis of bone in the reparative area, vascular image analysis on the boundary area were conducted. Results X-ray films, gross morphology observation, and histology observation: group B was superior to group A in terms of the growth of blood vessel into the implant, the quantity and the speed of the bone trabecula and the cartilage tissue formation, the development of mature bone structure, the remolding of shaft structure, the reopen of marrow cavity, and the absorbance and degradation of the implant. A value: there was significant difference between two groups 8, 12, and 16 weeks after operation (P lt; 0.05), and there were significant differences among those three time points in groups A and B (P lt; 0.05). For the ratio of neonatal trabecula area to the total reparative area, there were significant differences between two groups 4, 8, 12, and 16 weeks after operation (P lt; 0.05), and there were significant differences among those four time points in group B (P lt; 0.05).For the vascular regenerative area in per unit area of the junctional zone, group B was superior to group A 4, 8, 12, and 16 weeks after operation (P lt; 0.05). Conclusion Tissue engineered bone, seeded with the ARBM and wrapped by the pedicled fascial flap, has a sound reparative effect on bone defect due to its dual role of constructing vascularization and inducing membrane guided tissue regeneration.
Objective To investigate the clinical application of self-settingcalcium phosphate cement (CPC) in bone defect repair of extremities. Methods From May 1998 to January 2000, 32 cases of bone defect, in 36 sites, were repairedand reviewed, aged from 4 to 59 years old (24.7 years old on average), with bone defect 2 to 125 cm2 in size (13.1 cm2 on average). The causes of the bone defect werefracture, bone cyst, iliac bone harvesting, fibrous dysplasia, enchondroma and bone tuberculosis, which involved femur, iliac, tibia, humerus, phalanx, fibula, calcaneus, talus and acetabulum. All of the cases were followed up for 1 to 23 months, 15.3 months on average, before radiographic examination. Results All operations were successful and no general response was observed in all of the cases. X-ray examination showed an integrity interface between CPC and bone. And CT showed no gap existed. There was no increase of serum calcium and phosphate levels. Conclusion CPC is applicable in the low- or non-weight-bearing site of the extremities.
The treatmen t of the bone defect of the distal part of the radiu s included repair of the bone defect and resto rat ion of the funct ion of the w rist jo in t. Since 1979, th ree operat ive methods w ere u sed to t reat 13 cases, and they w ere graf t ing of the vascu larized f ibu la by anastom rsis f ibu lar vessels, graf t ing of upper part of f ibu lar w ith lateral inferio rgen icu lar artery and graf t ing vascu larized scapu la f lap. Follow up had been carried ou t from1 to 10 years. The resu lt w as sat isfacto ry. The discu ssion included the repair of the defect of the m iddle o r distal part of the radiu s, the operat ive methods, main at ten t ion s and indications. It was considered that it shou ld be based on the length of bone defect wh ile the operative method was considered.
OBJECTIVE: To investigate the ability of repairing bone defect with the compound of coralline hydroxyapatite porous (CHAP), fibrin sealant(FS) and staphylococcus aureus injection (SAI), and the feasibility to use the compounds as bone substitute material. METHODS: The animal model of bone defect was made on the bilateral radius of 54 New Zealand white rabbits, which were randomly divided into the experimental group(the defect was repaired with CHAP-FS-SAI), control group(with autograft) and blank control group(the defect was left unrepaired) with 18 rabbits in each group. The ability of bone defect repair was evaluated by gross observation, histopathological study, X-ray and biomechanical analysis 2, 4, 8 and 12 weeks after repair. RESULTS: (1) In the 2nd week, tight fibro-connection could be found between the implant and fracture site and there were many fibroblasts and capillary proliferation with many chondrocytes around CHAP in the experimental group, while only a few callus formed, and chondrocytes, osteoblast and osteoclast existed in the control group. (2) In experimental group and control group, a large quantity of callus was found 4 and 8 weeks; ossification of chondrocytes with weave bone formation were found 4 weeks and many osteocytes and weave bones and laminar bones were found 8 weeks. (3) In the 12th week, the complete ossification of implant with well bone remodeling, a large number of mature osteocytes and laminar were found in experimental group and control group, and CHAP still existed in the experimental group; the defect area filled with fibro-scar tissue and only many fibroblasts could be seen in blank control group. (4) X-ray findings were the following: In experimental and control groups, callus formation could be seen 2 weeks postoperatively, more callus formed 4 weeks, the bone defect area disappeared and CHAP scattered in the callus 8 weeks; the fracture line disappeared and medullary cavity became united (in control group); and in the 12th week, the cortex became continuous, the medullary cavity became united, and remodeling completed, while bone defect was not still united in blank control group. The maximal torque and torsional stiffness in the experimental group is higher than those in the control group 2 weeks (P lt; 0.05), but there was no significant difference (P gt; 0.05) between the two groups 4, 8, 12 weeks after repair. CONCLUSION: The compound of CHAP-FS-SAI has good biological compatibility, and it can be used for one kind of bone substitute material to repair the bone 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 construct tissue engineering bone with bio-derived materials and bone marrow stromal cells (MSCs), and to investigate the effect of allogeneic engineering bone implants on healing of segmental bone defects. METHODS: MSCs being aspirated aseptically from tibial tuberosities of young rhesus monkeys were induced into osteoblasts in vitro and then were cultured and marked with 5-bromo-2-deoxyuridine (BrdU). Tissue engineering bones were constructed with these labeled osteoblasts being seeded onto bio-derived materials made from fresh human bones which were treated physically and chemically, Then the constructs were implanted in 15 allogeneic monkeys to bridge 2.5 cm segmental bone defects of left radius as experimental groups, bio-derived materials only were implanted to bridge same size defects of right radius as control group. and, 2.5 cm segmental bone defects of both sides of radius were left empty in two rhesus monkeys as blank group. Every 3 monkeys were sacrificed in the 1st, 2nd, 3rd, 6th and 12th weeks postoperatively and both sides of the implants samples were examined macroscopically, histologicaly, and immunohistochemicaly. The two monkeys in blank group were sacrificed in the 12th week postoperatively. RESULTS: Apparent inflammatory reactions were seen around both sides of the implants samples in the 1st, 2nd, 3rd weeks, but it weakened in the 6th week and disappeared at the 12th week. The labeled osteoblasts existed at the 6th week but disappeared at the 12th week. The bone defects in experimental group were repaired and the new bone formed in multipoint way, and osteoid tissue, cartilage, woven bone and lamellar bone occurred earlier when compared with control group in which the bone defects were repaired in ’creep substitution’ way. The bone defects in blank group remained same size at the 12th week. CONCLUSIONS: Engineering bones constructed with bio-derived materials and MSCs were capable of repairing segmental bone defects in allogeneic monkeys beyond ’creep substitution’ way and making it healed earlier. Bio-derived materials being constituted with allogeneic MSCs may be a good option in construction of bone tissue engineering.
【Abstract】 Objective To evaluate the effect on repairing composite defect of mandible and skin by pre fabricatedmusculocutaneous flap including ectopic bone induced by BMP-2 and collagen in rabbits’ latissimus dorsimuscle. Meth ods Twenty-four rabbits (4-6 weeks old) were randomly divided into 3 groups: experimental, control and blank control group (n=8 in each group). Composite carriers composed of BMP-2 and collagen I sponge were implanted into latissimus dorsi muscle pouches of rabbits. The bone formation was evaluated with roentgenography, ALP staining, Von Kossa staining, HE staining, toluidine blue staining and CD31 immunohistochemical labell ing of microvessels. After 6 weeks, the mandibular defect of 8 mm in diameter with local skin defect of 2 cm × 3 cm was made in experimental group, and a musculocutaneous flap including ectopic-induced bone was prefabricated to transfer and repair the composite defect. The mandibular defect of 8 mm in diameter without local skin defect was made in control and blank control group. Free ectopic-induced bone was used for the repair of mandibular defect in control group, but repairing was not performed in blank control group. All the samples were detected 6 weeks after operation for tetracycl ine fluorescent staining, X-ray, histological examination and bone quantity analysis to evaluate the effect. Results Bone formation induced by BMP-2/collagen composites were found as woven bone between 4 to 6 weeks. It showed that cartilaginous osteogenesis was the mainly type of bone formation. Microvessels could beseen in the bony tissues. The composite defects of mandible and skin were healed well in the experimental group. Major bony tissue were seen in the control group, while it still remained bony defect in the blank control group. The bone quantity analysis in the experimental, control, and blank control group were (1.594 ± 0.674), (0.801 ± 0.036), and (0.079 ± 0.010) mm2, there were significant differences between each groups (P lt; 0.05). Conclusion Prefabrication of musculocutaneous flap including boneinduced by the composite of BMP-2 and collagen is feasible and prevalent. It can be regarded as vascularized bone graft and used in repairing composite defect of bone and skin.
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.
【Abstract】 Objective To review the progress in the treatment of bone defect by porous tantalum implant. Methods Recent l iterature was extensively reviewed and summarized, concerning the treatment method of bonedefect by porous tantalum implant. Results By right of their unique properties, porous tantalum implants have achievedvery good results in the treatment of certain types of bone defects. Conclusion Porous tantalum implants have their ownadvantages and disadvantages. If the case is meet to its indications, this method can obtain a good effect. Porous tantalum implants provide a new way for the cl inical treatment of bone defects.
Abstract To restore the bone defect after curettage of bone cyst, hydroxyapatite bioactive microcrystal glass (HBG) was used. From 1990 to 1995, HBG was applied in 17 cases. The bone involved were humerus, femur, tibia and fibula. Among them, 6 were complicated with pathological fracture. After eradication of the focus, the cyst was filled in ZnCl2 powder and irrigated with saline, then particles or segments of HBG were implanted into the cavity. The fracture were fixed with Enders rod. All the extremities were immobilized with plaster splint for about 6 to 8 weeks. Three months later, the lower limbs began to have functional exercises. By X-ray examination, the border between HBG and bone was clear in 2 weeks, after 1 month the clear border become blurred, and 2 months after operation, HBG was intermingled with bone. After 1 year there was neither absorption of bone nor HBG. No recurrence of the aptic lesion occurred in 1 year. HBG was a kind of artificial bone composed of hydroxyapatite and bioactive microcrystal glass, the latter contained silicon.It was characterized by its bioactivity, osteoinductivity and good tissue compatibility. The microcrystal would facilitate the growth of osseous tissues, which caused HBG intermingled with the surrounding bone. The source of HBG was abundant. It might be an ideal artificial bone.