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.
ObjectiveTo explore the feasibility of chitosan/allogeneic bone powder composite porous scaffold as scaffold material of bone tissue engineering in repairing bone defect. MethodsThe composite porous scaffolds were prepared with chitosan and decalcified allogeneic bone powder at a ratio of 1∶5 by vacuum freeze-drying technique. Chitosan scaffold served as control. Ethanol alternative method was used to measure its porosity, and scanning electron microscopy (SEM) to measure pore size. The hole of 3.5 mm in diameter was made on the bilateral femoral condyles of 40 adult Sprague Dawley rats. The composite porous scaffolds and chitosan scaffolds were implanted into the hole of the left femoral condyle (experimental group) and the hole of the right femoral condyle (control group), respectively. At 2, 4, 8, and 12 weeks after implantation, the tissues were harvested for gross observation, histological observation, and immunohistochemical staining. ResultsThe composite porous scaffold prepared by vacuum freeze-drying technique had yellowish color, and brittle and easily broken texture; pore size was mostly 200-300μm; and the porosity was 76.8%±1.1%, showing no significant difference when compared with the porosity of pure chitosan scaffold (78.4%±1.4%) (t=-2.10, P=0.09). The gross observation and histological observation showed that the defect area was filled with new bone with time, and new bone of the experimental group was significantly more than that of the control group. At 4, 8, and 12 weeks after implantation, the bone forming area of the experimental group was significantly larger than that of the control group (P < 0.05). The immunohistochemical staining results showed that osteoprotegerin (OPG) positive expression was found in the experimental group at different time points, and the positive expression level was significantly higher than that in the control group (P < 0.05). ConclusionChitosan/allogeneic bone powder composite porous scaffold has suitable porosity and good osteogenic activity, so it is a good material for repairing bone defect, and its bone forming volume and bone formation rate are better than those of pure chitosan scaffold.
Objective To study the effect of the allogeneic bone sheet that has been treated by the freezedrying and radiation sterilization in preventing the epidural adhesion after laminectomy in sheep. Methods Laminectomy was performed on L3,4and L4,5 of 12 adult male sheep. Afteroperation, one site of L3,4 or L4,5was covered by the allogeneicbone sheet in “H” shape after the freeze-drying and radiation sterilization treatment; and the other site was used as a control. The sheep were killed and the specimens were retrieved at 4，8，12，16，20 and 24 weeks after operation to observe the scar formation process. X-ray andCT scan were performed in the segments of L3,4and L4,5at 4 and 24weeks. Results Four weeks after operation, the position and the shape of the allogeneic bone sheet were good in condition, and no lumbar spinal stenosis or compression of the dura was found in the experimental sections. Twentyfour weeks after operation theexamination on the experimental sections revealed that the vertebral canal reconstruction was completed, the allograft was absorbed almost completely, and inosculation with the lamina of the vertebra and the shape of the lumbar spine were good, with no fibroid tissues found in the epidural area. Compared with the control segment, the dura adhesion degree in the laminoplasty segment was significantly decreased (Plt;0.01), and the dura sac remained in a good shape. There was no obvious compression on the dura. Conclusion The allogeneic bone sheet after the treatment of freeze-drying and radiation sterilization can effectively reduce the scar formation after laminectomy and prevent postoperative recurrence of the spinal stenosis.
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 efficacy of the pedicle screw fixation and allograft bone in posterior spinal fusion for the treatment of thoracolumbar vertebral fractures. Methods From September 2006 to March 2008, 105 cases of thoracolumbar vertebral fractures were treated with allograft bone in posterior spinal fusion after the pedicle screw fixation,including 75 males and 30 males aged 15-65 years (mean 37 years). The mixture which consisted of spinous process and vertebral plate sclerotin and homogeneity variant bone was used as bone graft to implant into articular process and processus transversus space or vertebral plate space. The time from injury to surgery varied from 8 hours to 21 days, with an average of 3 days. There were 52 cases of fall ing injuries from height, 35 cases of traffic accident injuries, 11 cases of bruise injuries and 7 cases of tumbl ing injuries. Before operation, the primary cl inical symptoms of patients included local pain combined with l imitation of activity, 30 cases compl icated by various degrees of spinal cord and nerve root functional disturbance. According to Mcaffee classification, there were 7 cases of flexion depressed fractures, 86 cases of blow-out fractures, 9 cases of Chance fractures and 3 cases of dislocation-fracture. According to Frankel grade, there were 11 cases of grade A, 2 cases of grade B, 7 cases of grade C, 10 cases of grade D and 75 cases of grade E. The X-ray examination of all patients denoted that the bodies of injuryed vertebra were compressed and wedge-shaped, and the CT scan showed that 98 cases had spinal stenosis. After 2 weeeks and 3, 6, 12 months, the X-ray films were taken to evaluate bone graft fusion. The Cobb angle was measured. The recovery of nerve function was analyzed. Results The operation time was 55-180 minutes (mean 90 minutes) and the blood loss was 100-900 mL (mean 200 mL). All patients achieved heal ing by first intention with no compl ication. After operation, 93 cases were followed up for 6-15 months with an average of 11 months. Except for 11 patients who were at grade A before operation, one to two grade recover was observed in other patients. The average Cobb angle of injury segment was improved from preoperative 32.1° to postoperative 5.2°. The height of anterior border of injuried vertebral body was recovered from the preoperative average compressed remaining height 61.5% to postoperative 96.8%. The vestigial degree of canal is spinal is anteroposterior diameter was recovered from preoperative 65.7% to postoperative 89.9%. Imageology examination showed that all the patient achieved bone union within 6 months. The fusion rate of bone graft in spinal fusion was 100%. No loosening and breaking of nails occurred. Conclusion Pedicle fixators can restore and fix the thoracolumbar fractures, and the combination of autograft and allograft bone transplantation is a safe, rel iable and effective method.
Objective To investigate the clinical application and complicationof the lyophilized small-segment allogeneic bone used in repairing bone defectscaused by benign bone tumor and tumor-like lesions after resection and curettage. Methods From December 1999 to December 2005, 230 patients (156 males, 74 females; age, 5-56years, averaged 32.8 years), who had bone defects caused by benign bone tumors and tumor-like lesions after surgical resection and curettage, were treated by the lyophilized small-segment allogeneic bones. The cavities left by the tumor curettage ranged in size from 1.0 cm×0.8 cm to 10.0 cm×2.0 cm, andthe bone defects were about 1.0 to 3.5 cm in diameter after the localized resection of the bones. According to the bone defect degrees, the autogenous nonvascular iliac bone and the bone allograft (0.5-30.0 g) were implanted, followed by the drainage for 2-3 days and the use of antibiotics to prevent infection. The postoperative systemic and local reactions were observed, and the regular X-ray examinations were performed to observe the bone union. ResultsThere was no significant difference in the allergic reactions, such as postoperative temperature, drained amount, and body swelling, between this kind of transplantation and the autogenous bonetransplantation. The wounds in 196 patients were healed by the first intension.The wounds in 34 patients had extravasate. Among them, the wound was healed by changing dressing in 30cases; the wound had delayed healing in 4, including 3 whose wounds were healedby changing dressing for 3-4 weeks,and 1 whose wound was healed by taking out the implants. The follow-up for 6-60 months (average, 38 months) revealed that all the patients had the allograft unions of the bones within 6-18 months after the transplantation, and only 6patients had recurrence of the tumor (3.0%). Evaluated by the Mankin,Komender and WANG Zhiqiang’s standards, 196 (85.22%) patients were satisfied with their outcomes while the other 34 (14.78%) patients were not satisfied. Conclusion The lyophilized small-segment allogeneic bone has a good compatibility and osteogenesis, when it is used in repairing bone defects caused by benign bone tumor and tumor-like lesions after resection and curettage. So, this kind of bone is a good, convenient and safe material for the bone transplantation. The important factors affecting the allograft union are as follows: the mechanical stability in the recipient region, local blood supply, and management of the bone cavity left by resection and curettage of the bone tumor.
ObjectiveTo investigate the short-term effectiveness of allogeneic bone transplantation for pelvic reconstruction of large skeletal defects after tumor resection. MethodsBetween January 2008 and November 2009, 9 patients with pelvic tumor were treated, and the clinical data were retrospectively analyzed. There were 1 male and 8 females with an average age of 36.1 years (range, 18-44 years). There were 5 cases of giant cell tumor of bone, 2 cases of chondrosarcoma, 1 case of malignant giant cell tumor of bone, and 1 case of Ewing sarcoma. According to the Enneking system for staging musculoskeletal tumors, the lesion involved ilium (region I) in 4 cases, acetabulum (region II) in 6 cases, pubis and ischium (region III) in 3 cases, and sacrum (region IV) in 1 case. The average disease duration was 6.8 months (range, 1-36 months). After accurate resection of the tumor, allograft ilium with or without acetabulum was used in 6 cases and 2 cases respectively, and allogenous bone plate in 1 case for pelvic reconstruction; total hip arthroplasty was performed in 6 cases; sacrum screw was used in 1 case. ResultsInfection of incision and abdominal distention occurred in 1 case, and was cured after debridement; primary healing of incision was obtained in the other cases, without infection, lower limb deep venous thrombosis, or dislocation. The average follow-up was 11.8 months (range, 8-15 months). The X-ray films showed breakage of plate in 1 case at 8 months after operation and partial bone resorption in 2 cases; good position of the prosthesis, plate, and transplanted bone was observed in the other cases. No local recurrence was found. At last follow-up, the average musculoskeletal tumor score (MSTS) was 23 (range, 18-29). ConclusionAllogeneic bone transplantation for pelvic reconstruction of large skeletal defects after tumor resection can achieve satisfactory short-term surgical and functional effectiveness.
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 investigate cl inical therapeutic effect on early stage femoral head necrosis managed with allogeneic cortical bone cage support combining with autologous cancellous bone grafting through core decompression tunnel, and to discuss its effect on preventing femoral head collapse and influence factors. Methods From January 2002 to December2005, 40 patients (42 hips) with femoral head necrosis underwent core decompression and an allogeneic threaded cortical bone supporting cage which was loaded with autologous cancellous bone inside. There were 26 males and 14 females, aging 27-45 years (mean 35.6 years). The disease course was 6-28 months (mean 18.3 months). All the cases underwent X-ray, CT and MRI examination to confirm the diagnosis and necrosis area. Twelve hips were at Ficat stage I, 29 hip at stage II, and 1 hips at stage III. Harris hip score system was used to evaluate the hip function pre- and post-operatively. X-ray films were taken regularly after operation. Results All the wound healed by first intention without any compl ications such as infection, fracture, nerve and vascular injury, and deep vein thrombosis. Thirty-six patients (38 hips) were followed up for 24-58 months with an average of 38 months. All the patients had different degrees of improvement in cl inical symptoms. According to Harris hip score system, the Harris score was 63.1 ± 6.4 before operation and 82.3 ± 16.5 at the last follow-up, showing significant difference (P lt; 0.001). The results were excellent in 24 hips, good in 11 hips, fair in 2 hips and poor in 1 hips. The X-ray films showed femoral head repairing and no advancement of osteonecrosis and collapsing in 23 patients (24 hips) 24 months after operation. Conclusion Allogeneic cortical bone cage support combining with autologous cancellous bone grafting is suitable for managing early stagefemoral head necrosis and its short- and middle-term effect is satisfactory.
Objective To investigate the osteoblasts effect, compl ications and influencing factors in the appl ication of small freeze-drying allogeneic bone plots mixed autologous bone fragments in spinal surgery, and to compare with autogenous bone graft. Methods From January 2003 to January 2007, 515 cases of spinal injuries were treated. A total of 324 cases weretreated with small freeze-drying allogeneic bone plots mixed with autologous bone grafts (group A), including 211 males and 113 females with an average age of 36 years (18-83 years). There were 182 cases of thoracolumbar vertebra fracture, 68 cases of lumbar spondylol isthesis, 47 cases of lumbar vertebral canal stenosis, 17 cases of cervical disc herniation, 5 cases of cervical spine fracture-dislocation and 5 cases of thoracolumbar vertebra tumor. The weight of bone graft was 10-60 g (mean 30 g). A total of 191 cases were treated with autogenous bone grafting (group B), including 135 males and 56 females with an average age of 32 years (23-78 years). There were 109 cases of thoracolumbar vertebra fracture, 23 cases of lumbar spondylol isthesis, 17 cases of lumbar vertebral canal stenosis, 19 cases of cervical disc herniation, and 23 cases of cervical spine fracture-dislocation. The weight of bone graft was 10-50 g (mean 25 g). Results In group A, effusion of wound increased in 4 cases and the result of bacterial culture was negative; effusion was absorbed after 2 weeks of local irrigation, drainege and cortin management. In group B, no obvious effusion was observed. The follow-up time was 10-36 months (mean 17.4 months) in group A and 8-36 months (mean 16.8 months) in group B. The bone heal ing was achieved in 308 cases within 4-10 months (mean 8.1 months) and in 184 cases within 4-10 months (mean 5.8 months), and the bone fusion rates were 95.06% and 96.34% in groups Aand B, respectively. There was no significant difference in bone fusion rate between groups (P gt; 0.05). According to Mankin and Komender evaluation standard, the response rates were 95.06% and 96.34% in groups A and B, respectively, showing no significant difference (P gt; 0.05). Conclusion Mix-bone grafting has the same effective to autologous bone grafting in bone fusion rate. It could be used as the supplement of the autologous bone inadequacy.