OBJECTIVE To investigate the effect of allogeneic decalcified bone graft in the treatment of nonunion in children. METHODS From April 1990 to September 1997, 17 children with nonunion were adopted in this study. Among them, there were 10 boys and 7 girls, the age ranged from 2 to 13 years. The allogeneic decalcified bone graft taken from fresh corpse by aseptic manipulation were used to repair 3 cases of congenital nonunion and 14 cases of acquired nonunion. RESULTS All cases were followed up 2 to 9 years after operation, 9 cases were cured successfully and 7 cases were cured after twice operations. One case of congenital pseudoarthrosis of the tibia was operated twice and there were callus grown half years after the second operation, but reoccurred after one year. Although there were 1.5 cm to 3 cm shortening deformity of extremity including another 2 cases of congenital pseudoarthrosis of the tibia and 5 cases of nonunion caused by chronic osteomyelitis, the function of joint was normal. CONCLUSION Treatment of nonunion in children by allogeneic decalcified bone graft is a valuable technique in clinical practice. It is characterised by high capacity of osteoinduction, low antigenicity, rapid bony union, plentiful source of bone graft and convenient utilization.
Objective To investigate the adhesiveness of osteoblasts and vascular endothel ial cells from rat BMSCs co-cultured on allogeneic freeze-dried partially bone in vitro. Methods The BMSCs were isolated from 4-week-old SD rats (weighing 100-110 g) and cultured in vitro. The third generation of BMSCs were induced into osteoblasts and vascular endothel ial cells. The osteoblasts and vascular endothel ial cells after being induced for 7 days in a ratio of 1 to 1 were directlyco-cultured (experimental group), while the second generation of uninduced BMSCs was used as a control (control group). The growth and prol iferation abil ity were analyzed by MTT examination and the growth curve was drawn at 1-8 days. The osteoblasts and vascular endothel ial cells after being induced for 14 days were implanted in the allogeneic freeze-dried partially bone coated by 20% Col I or not at different densities (0.25 × 106/mL、0.50 × 106/mL、1.00 × 106/mL、2.00 × 106/mL、4.00 × 106/mL), as modified group and unmodified group, the cell adherence rate was calculated after 24 hours. These two kinds of cells were implanted in the pre-disposal treated allogeneic freeze-dried partially bone and observed by scanning electron microscope. Results ALP staining of osteoblasts showed that there were blue grains in cytoplasm at 7 days. CD31 and CD34 immunocytochemical staining of vascular endothelial cell showed that there were positive signals in the cytoplasm at 14 days. The MTT test showed that the prol iferation level of the experimental group was lower than those of the control group. There were significant differences in absorbance value between two group from 3 days to 8 days (P lt; 0.05). The cell adherence rate increased with increasing seeding density when the seeding density was (0.25-1.00) × 106/mL. The cell adherence rate reached the peak when the seeding density was 1.00 × 106/mL. The cell adherence rate decreased when the seeding density was more than 2.00 × 106/mL. There were significant differences in cell adherence rate between modified group and unmodified group at different seeding densities (P lt; 0.05). The prol iferation of the osteoblasts and endothel ial cells presented better growth and histocompatibil ity under scanning electron microscope. Conclusion The growing behavior of two kinds of cells is good in the allogeneic freezedried partially bone coated by 20% Col I , which can be used in reconstrction of vascularized tissue engineered bone.
Objective To study the repair and function reconstruction of complex soft tissue defect of posterior of hand and forearm. Methods From May 2001 to November 2003, 8 cases of soft tissue defect of posterior of hand and forearm were repaired with thoracico abdominal flaps with hilum for primary stage. The tendon transplantation and allogeneic tendon function reconstruction of hand were performed for secondary stage. The range of the flap was 9 cm×15 cm to 12cm×38 cm. Allogeneic tendon amounted to 6.Results All the flaps survived. The flap countour was good. The results of allogeneic tendon transplantation were satisfactory and the function of hand was good. Conclusion Repairing complex soft tissue defect of posterior of hand and forearm and reconstructing hand function by use of thoracico abdominal flaps with hilum and transplantation of allogeneic tendon have the satisfactory clinical results.
Objective To explore the clinical application of allogeneic bone transplantation. Methods Related literatures on clinical application of various allograft bone materials of the past 5 years were extensively reviewed. Results The allografts could be processed into various kinds of transplanting materials, such as small blocks, large segments, morselised or granular material, and bone ring, so that they could be applied to bone defect filling, prosthesis revision, limb preservation after tumor resection, and joint fusion. All these applications ended up with good clinical results. However, complications resulted in thestructural transplantation of large block bones could be overlooked. Conclusion The main advantage of bone allograft is that it can be integrated with host bone and be remodelled, so as to reconstruct bone structure and function. How to accelerate their integration and remodelling while exerting normal functions is the problem that requires solution.
Objective To investigate the expression levels and significance of vascular endothel ial growth factor (VEGF) and microvessel density (MVD) in rabbit radius defects repaired with allogeneic and autogenic bone. Methods Forty adult New Zealand rabbits were chosen, and 10 mm bone defect model was created in the bilateral radii of 28 experimental rabbits. The other 12 rabbits provided allogeneic bone under the standard of American Association of Tissue Bank. In the left side, allogeneic bone were used to repair bone defect (experimental group), equal capacity autogenous il iac bone was used in the right side (control group). Animals were sacrificed at 2, 4, 8, and 12 weeks postoperatively. Immunohistochemical method was used to determine the expression of VEGF, CD34 protein and MVD counting. Bone histomorphometric parameters, including percent trabecular area (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp) were measured by von Kossa staining undecalcified sl ices. The relation was analyzed between VEGF and MVD, histomorphometric parameters. Results The positive signals of VEGF protein were detected in cytoplasm of vascular endothel ial cells, chondrocytes, osteoblasts, fibroblasts and osteoclasts. At 2 weeks, there was no significant difference in VEGF protein expression between experimental group and control group (P gt; 0.05); at 4 and 8 weeks, the expression of VEGF in control group was significantly higher than that in experimental group (P lt; 0.05); and at 12 weeks, there was no significant difference between two groups (P gt; 0.05). There was a positive correlation (P lt; 0.01) between VEGF expression and MVD value in two groups at 2, 4, 8, and 12 weeks postoperatively. There was no significant difference in bone histomorphometric parameters (BV/TV, Tb.Th, Tb.N, Tb.Sp) between two groups at 12 weeks postoperatively (P gt; 0.05), but there was a positive correlation between VEGF expression and parameters of BV/TV, Tb.Th, and Tb.N (P lt; 0.01); and a negative correlation between VEGF and Tb.Sp (P lt; 0.01). Conclusion VEGF can express diversity at different time and positions, and the different expressions indicated various biology significances in the process of the bone heal ing. It can coordinate growth of cartilage and bone and profit vascular reconstruction of allogeneic bone. VEGF may participate in promoting osteogenesis in the course of allogeneic bone transplantation.
OBJECTIVE: To observe the difference of the fracture reparation using autogeneic-iliac bone and allogenic bone. METHODS: Comminuted fracture of humerus in two sides were made in rabbits. Autogeneic-iliac bone was implanted in one side, while allogenic bone of equal capacity was implanted in the other side. General observation, X-ray, and HE histologic section were done when the rabbits were put to death in different stages. RESULTS: One week after implantation, the graft had been enclosed by connective tissue without infiltration of the inflammatory cells. At the 2nd week, the graft had been enclosed in osteoplastic granulation tissue, and the cartilage callus had formed. At the 3rd week, there had been broken sequestrum among the callus; the cartilage had actively formed the bone; and the medulla had been making. At the 4th week, the sequestrum had disappeared, and the mature callus had appeared; the osteoblasts had arranged in a line around the edge of the mature callus. At the 5th week, the callus was b, compact and approached mature bones. At the 6th week, there had been the compact lamellar structures and the complete haversian’s systems. There was no significant difference between callus of two sides by using image quantitative analysis in the 3rd, 4th week (P gt; 0.05). CONCLUSION: The allogenic bone has good histocompatibility and bone conduction effect, and can be used for bone transplantation substitute with autogenous-iliac bone.
Objective To investigate the clinical results of allograft and sural neurovascular flap in repairing calcaneus and skin defects.Methods From February 1996 to December 2002, allograft and sural neurovascular flap were used to repair calcaneusand skin defects in 6 cases. The causes included road accident in 3 cases, strangulation in 2 cases and crashing object in 1 case. The defect locations were at theback of the calcaneus( 1/3, 1/2 and 2/3 of calcaneus in 3 cases, 2 cases and 1case respectively). The flap area ranged from 6 cm×7 cm to 12 cm×17 cm. Results The flaps survived completely in 4 cases; the distal flaps necrosed partly in 2 cases and the wound healed by dressing. The postoperative X-ray films showed that the repaired bone and joint had normal position and the arcus plantaris recovered. After a follow upof 6 months to 3 years all the patients were achieved bone union in allograft and had no complications of absorption, infection and repulsion. The weightbearing and walking functions were restored and the injured foot obtained a satisfactory contour. After 36 months of operation, the sensory recovery of foot occurred. Conclusion The used-allograft iseasy to be obtained and arcus plantaris is easy to recover. The reversesural neurovascular- flap in repairing calcaneus and skin defects has the following advantages: the maintenance of blood supply for injured foot, the less dangerous operation, the simple procedure, the recovery of walking function, and the good appearance and sensation.
OBJECTIVE: To investigate the repairing effect of transplantation of allogeneic fetal bone in combination with a covering cryopreserved periosteal allograft to bone defect. METHODS: Twenty Long-eared white male rabbits were chosen as experimental model of bilateral 12 mm combined bony and periosteal radial defect. Cryopreserved allograft periosteum with allogeneic fetal bone were implanted in the left defect as experimental side and fetal bone was simply transplanted in the right defect as control side. Bone repair process in the two groups were compared by macroscopy, microscopy, roentgenograms and the contents of calcium and phosphate in the defect area at 2, 4, 8 and 12 weeks after transplantation. RESULTS: There was significant statistic difference in the contents of calcium and phosphate between the experimental and control sides at 4, 8 and 12 weeks after transplantation (P lt; 0.05). With time passing by, the contents of calcium and phosphate have the increasing trends. In the experimental group, lamella bone was seen and medullary canal recanalized at 8 weeks postoperatively. The histological section showed the bone lacuna and lamella bone were formed. CONCLUSION: It suggests that allogeneic fetal bone in combination with a covering cryopreserved periosteal allograft can promote bone repair, and allogeneic fetal bone is excellent bone substitute.
Objective To give a prel iminary experimental evidence and to prove chitosan and allogeneic morsel ized bone as potential bone substitutions in repairing rabbit radius segmental defect. Methods Chitosan and allogeneic morsel ized bone were mixed with various ratios (1 ∶ 5, 1 ∶ 10, 1 ∶ 25, 1 ∶ 50, and 1 ∶ 100). After preparation, the physicaland chemical properties of the composites were prel iminary detected; the composites at the ratios of 1 ∶ 50 and 1 ∶ 25 had good physical and chemical properties and were used for the animal experiment. The radius segmental defects of 15 mm in length were made in 50 adult New Zealand white rabbits (weighing 2.5-3.0 kg), then the animals were divided into 2 groups. In groups A and B, chitosan/allogeneic morsel ized bone composites were implanted at the ratio of 1 ∶ 50 and 1 ∶ 25, respectively. After 1, 2, 4, 8, and 12 weeks of operation, the gross, histological, immunohistochemical observations were performed. Before the rabbits were sacrified, X-ray films were taken; the serum calcium and alkal ine phosphatase (ALP) concentration were measured; and the biomechanical measurement was carried out at 12 weeks. Results The results of gross observation were essentially consistent with those of the X-ray films. The histological observation showed that the bone formation was earl ier in group A than in group B; the amount of new bone formation in group A was more than that in group B; and the bone forming area in group A was bigger than that in group B (P lt; 0.05) at 4 and 8 weeks after operation. The immunohistochemical staining showed that vascular endothel ial growth factor and insul in-l ike growth factor receptor II proteins expressed in the cytoplasm of 2 groups after 4 and 8 weeks, and the expression in group A was higher than that in group B (P lt; 0.05). There was no significant difference in the serum calcium concentration between 2 groups at each time point (P gt; 0.05). After 4 and 8 weeks, the ALP concentration in group A was significantly higher than that in group B (P lt; 0.05). After 12 weeks, the radius maximum bending loads of groups A and B were (299.75 ± 27.69) N and (278.54 ± 17.09) N, respectively, showing significant difference (t=4.045,P=0.002). Conclusion The composite of chitosan and allogeneic morsel ized bone has good osteogeneic activity and can beused as a bone tissue engineering scaffold, and the optimum ratio of chitosan to allogeneic morsel ized bone was 1 ∶ 50.
OBJECTIVE: To sum up the clinical results of allogeneic humeral transplantation with vascular anastomosis, and evaluate the clinical significance. METHODS: From September to November 1979, 1 case with humeral shaft defect of 10 cm in length and 2 cases with tibia shaft defect of 12 cm in length were repaired by allogeneic humeral transplantation with vascular anastomosis. Azathiopurine and prednisone were applied for 3 months postoperatively. All cases were followed up for 20 years. RESULTS: Case 1 recovered well with good bone union and reconstruction after operation, and could work normally. In case 2, five chronic rejections were occurred during 3 years after operation, and recovered after treatment, the allograft bone was fractured after 2 years of operation, and unioned by autogeneous iliac bone transplantation. In case 3, the distal part of allograft bone was fractured after 46 months, and unioned by autogeneous iliac bone transplantation. The middle part of allograft bone was non-unioned after 20 years follow-up in case 3, but the patient could still work normally. CONCLUSION: The clinical results of allogeneic long bone transplantation can be improved by rational tissue matching test, application of effective immunosuppressive drugs in a certain period according to the principles of modern transplantation immunology.
