骨蛋白强化脱钙骨基质板块修复犬长骨节段性骨缺损

目的 :研究骨蛋白 (boneprotein ,BP)强化脱钙骨基质 (demineralizedbonematrix ,DBM) (BP/DBM )板块在修复节段性骨缺损中的作用。方法 :在犬双侧桡骨中段各做一 1 5cm的骨膜骨缺损 ,分别植入板块状BP/DBM ,DBM ,自体髂骨块及留置空白 ,观察时间为 4个月。结果 :BP/DBM植入组有 3例完全骨愈合 (3 / 5 ) ,自体骨移植组只有 3例部分骨愈合 ,单纯DBM组及空白组未见骨愈合。生物力学测试 :术后 4个月BP/DBM组新生骨极限压缩强度值最高 ,已达到正常桡骨组织的 48%。BP/DBM组新生骨为成熟的板状骨。结论 :BP/DBM板块可促进节段性骨缺损的修复。     

Repair of large segmental bone defects using bone marrow stromal cells with demineralized bone matrix

Objective: The aim of the present study was to evaluate the effect of tissue‐engineered constructs on repair of large segmental bone defects in goats. Methods: Allogenic demineralized bone matrix (aDBM) was seeded with autologous marrow stromal cells (aMSC) for seven days to construct DBM–MSC grafts prior to implantation. 24 goats were randomly divided into three groups (eight in each). In each group, 3 cm diaphyseal femoral defects were created unilaterally, and subsequently filled with the DBM‐MSC grafts, DBM alone and an untreated control, respectively. Radiological analysis and biomechanical evaluation were performed at 12 and 24 weeks after operation. Results: Obvious increases in radiological scoring and biomechanical strength were found in the DBM‐MSC group when compared to the DBM group. X‐ray examination showed excellent bone healing in the DBM‐MSC group, whereas only partial bone repair was seen in the DBM group, and no healing in untreated controls. Histologically, a tendency to bone regeneration and remodeling was far more obvious for the DBM‐MSC group than the DBM only and untreated controls. Conclusion: Our results strongly suggest that transplantation of bone MSC within a DBM could have advantages for the bone repair of large segmental defects.     

海绵状、泥灰状脱钙骨基质修复骨缺损

目的探讨海绵状脱钙骨基质(DBM)和泥灰状DBM修复骨缺损的能力。方法将兔四肢长骨骨干脱脂、脱钙后制成长度为500～1000 μm的纤维状及直径为200～400μm的颗粒状DBM,并与2%明胶混合分别制成海绵状DBM和泥灰状DBM。在9只兔双侧桡骨中段做一长10mm的骨膜骨缺损,分别植入海绵状DBM和泥灰状DBM及空白对照,每组各6个缺损,术后观察6周,于4、6周时拍摄X线片,并对实验动物的大体标本、骨密度、生物力学、新生骨矿化率及病理组织学改变进行观察。结果术后4、6周X线片显示两实验组骨缺损均修复,骨髓腔完整;空白对照组无一例修复骨缺损。骨密度测量显示海绵状DBM组新生骨骨密度与正常桡骨间差异无显著性(P >0.05),但泥灰状DBM组的新生骨骨密度与正常桡骨间差异有显著性(P< 0.05)。术后6周生物力学测定显示海绵状DBM组新生骨极限压缩强度值与正常桡骨差异无显著性(P >0.05),泥灰状DBM组低于正常桡骨且差异有显著性(P< 0.05)。两实验组新生骨矿化率差异无显著性(P >0.05)。组织学观察显示两实验组中DBM绝大部分被吸收,形成板状骨骨小梁及完整的骨髓腔,塑形完整, 新生骨内可见骨单位及局部尚未完全骨化的新生骨。结论海绵状DBM和泥灰状DBM均具有诱导成骨活性和骨传导能力,使用方便,新生骨塑形完整,生物力学强度高,矿化     

Accelerated repair of cortical bone defects using a synthetic extracellular matrix to deliver human demineralized bone matrix.

Injectable hydrogel and porous sponge formulations of Carbylan-GSX, a crosslinked synthetic extracellular matrix (ECM), were used to deliver human demineralized bone matrix (DBM) in a rat femoral defect model. A cortical, full-thickness 5-mm defect was created in two femurs of each rat. Six rats were assigned to each of five experimental groups (thus, 12 defects per group). The defects were either untreated or filled with Carbylan-GSX hydrogel or sponges with or without 20% (w/v) DBM. Radiographs were obtained on day 1 and at weeks 2, 4, 6, and 8 postsurgery of each femur. Animals were sacrificed at week 8 postsurgery and each femur was fixed, embedded, sectioned, and processed for Masson's Trichrome staining. The bone defects were measured from radiographs and the fraction of bone healing was calculated. The average fractions of bone healing for each group were statistically different among all groups, and all treatment groups were significantly better than the control group. The Carbylan-GSX sponge with DBM was superior to the sponge without DBM and to the hydrogel with DBM. Histology showed that defects treated with the Carbylan-GSX sponge plus DBM were completely filled with newly generated bone tissue with a thickness comparable to native bone. Carbylan-GSX sponge was an optimal delivery vehicle for human DBM to accelerate bone healing.     

Mechanisms of action of demineralized bone matrix in the repair of cortical bone defects

Demineralized bone matrix commonly is used to enhance and to facilitate bone grafting after skeletal injury or disease; however, the biologic bases for its bone-inducing abilities remain obscure. We have taken advantage of a mouse model of cortical bone defect healing to elucidate its mechanisms of action in vivo. Demineralized bone matrix combined with hyaluronan improved skeletal healing by inducing early deposition of an osteoid matrix. Demineralized bone matrix combined with hyaluronan might accelerate bone formation because it serves as a scaffold on which osteoprogenitor cells attach. We tested this possibility by comparing demineralized bone matrix combined with hyaluronan with heat-inactivated demineralized bone matrix combined with hyaluronan and found that the intact material was superior in terms of its ability to stimulate new bone formation. We also compared the bone inducing capacity of demineralized bone matrix combined with hyaluronan with a synthetic collagen sponge and found that not only the synthetic collagen scaffold delayed bone healing but also impaired bony bridging at later stages of repair. Another important property of demineralized bone matrix combined with hyaluronan was its ability to become actively degraded by osteoclasts during healing. Therefore, demineralized bone matrix combined with hyaluronan may not only attract osteoblasts and stimulate their differentiation, but also induce bone matrix resorption, which is a critically important regulator of bone formation and mineralization.     

自体外周血干细胞与脱钙骨复合移植修复骨缺损的临床应用

目的：观察自体外周血干细胞(APBSC)与脱钙骨(DBM)复合移植治疗良性骨肿瘤术后骨缺损的疗效。方法：对12例骨肿瘤患者，手术切除骨肿瘤脱钙骨填充骨缺损，术后第7天行骨髓动员，每天皮下注射特尔立3．0μg／kg，连续3d，第4天静脉滴注10mg地塞米松后采集APBSC。在X线电视透视下将一枚骨穿针准确穿入骨缺损部位，然后抽取自体外周血干细胞即可注入骨缺损部位。通过术后连续X线片，了解其骨缺损修复能力。结果：12例病人术后得到随访，时间为4～16个月，在2～4个月以内均开始有不同程度的骨化，成骨效应满意。结论：自体外周血干细胞(APBSC)／脱钙骨(DBM)复合移植是一种治疗骨缺损有效的新方法。     

脱钙骨基质复合牛骨形态发生蛋白与单纯脱钙骨基质修复兔桡骨缺损比较

目的比较脱钙骨基质(DBM)复合牛骨形态发生蛋白(bBMP)和单纯DBM修复节段性骨缺损的能力.方法32只新西兰大白兔采用桡骨15 mm节段性骨缺损模型,随机分为2组:A组植入异体DBM与bBMP(10 mg)复合材料;B组植入异体DBM.术后4、8、12、16周,进行放射学检查、病理组织学检查和计算机图象分析新生骨面积.结果X线和组织学检查显示异体DBM与bBMP复合材料组的新骨生成、修复骨缺损能力优于异体DBM组,组织切片的计算机图象分析提示DBM bBMP组修复新骨面积大于DBM组,两者之间差异有显著性(4、8、12周P＜0.05,16周P＜0.01).结论异体DBM复合bBMP材料通过骨诱导和骨传导两种方式修复骨缺损,其修复骨缺损的能力要优于单纯DBM材料,是一种较为理想,具有高效成骨活性的植骨材料.     

Repair of long bone defects with demineralized bone matrix and autogenous bone composite

Background:

Repair of diaphyseal bone defects is a challenging problem for orthopedic surgeons. In large bone defects the quantity of harvested autogenous bone may not be sufficient to fill the gap and then the use of synthetic or allogenic grafts along with autogenous bone becomes mandatory to achieve compact filling. Finding the optimal graft mixture for treatment of large diaphyseal defects is an important goal in contemporary orthopedics and this was the main focus of this study. The aim of this study is to investigate the efficacy of demineralized bone matrix (DBM) and autogenous cancellous bone (ACB) graft composite in a rabbit bilateral ulna segmental defect model.

Materials and Methods:

Twenty-seven adult female rabbits were divided into five groups. A two-centimeter piece of long bone on the midshaft of the ulna was osteotomized and removed from the rabbits’ forearms. In group 1 (n=7) the defects were treated with ACB, in group 2 (n=7) with DBM, and in group 3 (n=7) with ACB and DBM in the ratio of 1:1. Groups 4 and 5, with three rabbits in each group, were the negative and positive controls, respectively. Twelve weeks after implantation the rabbits were sacrificed and union was evaluated with radiograph (Faxitron), dual-energy x-ray absorptiometry (DEXA), and histological methods (decalcified sectioning).

Results:

Union rates and the volume of new bone in the different groups were as follows: group 1 - 92.8% union and 78.6% new bone; group 2 - 72.2% union and 63.6% new bone; and group 3 - 100% union and 100% new bone. DEXA results (bone mineral density [BMD]) were as follows: group 1 - 0.164 g/cm², group 2 - 0.138 g/cm², and group 3 - 0.194 g/cm².

Conclusions:

DBM serves as a graft extender or enhancer for autogenous graft and decreases the need of autogenous bone graft in the treatment of bone defects. In this study, the DBM and ACB composite facilitated the healing process. The union rate was better with the combination than with the use of any one of these grafts alone.     

Experimental repair of segmental bone defects in rabbits by demineralized allograft covered by free autogenous periosteum

Using an experimental model of segmental bone defect in the ulna of rabbits we investigated the effect on bone healing of fresh cancellous autograft (FCA), demineralized deep-frozen allograft (DDA), and demineralized deep-frozen allograft covered with free autogenous periosteum (DDAwP). Radiologically, it was found that the results of the FCA and DDAwP groups were superior to those of the DDA group. This superiority was statistically significant after the 3rd to the 9th week for the FCA group, and the 6th to the 9th week for the DDAwP group. However, bone formation and union in the DDA group reached the same level of those in the other groups after 12 weeks. When the all histological findings were compared at the 12th week, the FCA and DDAwP groups were statistically superior to the DDA group in terms of proximal union. On distal union, the FCA group was statistically superior to the DDA group. Biomechanically, the FCA and DDAwP groups were statistically superior to the DDA group in terms of maximum torque and energy absorption. The DDAwP group was superior to the DDA group in term of stiffness. We conclude that ossification could be more easily achieved if demineralized deep-frozen allograft is covered with periosteum when faced with the need for quicker and better quality bone integration.     

Traumatic segmental bone defects in the upper extremity. Treatment with exposed grafts of corticocancellous bone

We treated twenty-two consecutive patients for an open fracture and segmental loss of bone in the upper extremity by delayed insertion of a graft of iliac corticocancellous bone. All of the wounds were left open and healed by secondary intention. Sixteen patients (nineteen grafts) had long-term follow-up. Ten injuries were secondary to a gunshot wound. The ten patients (twelve grafts) who had an injury to the hand were followed for an average of 24.1 months. No patient in this group had an infection, and all had primary union after an average of 13.3 weeks. Nine had a satisfactory result. The other six patients (seven grafts) had an injury to the arm or forearm and were followed for an average of 30.2 months. There were four non-unions, one refracture, and no persistent infections. The final result was satisfactory in five and unsatisfactory in one patient. Fourteen of the nineteen grafts were inserted within seventeen days after the initial injury. All nine of the grafts in the hand that were inserted early did well, but three of the other five (in the arm or forearm) became infected. The method that was used in the patients who had an open injury of the hand allowed early active motion and quick rehabilitation. The exposed cortical bone was not prone to infection. The technique has limited application in patients who have an open injury of the arm or forearm because of a high incidence of complications.     

Combined use of platelet-rich plasma and autologous bone grafts in the treatment of long bone defects in mini-pigs

The use of platelet-rich plasma (PRP) for improving of bone defect healing is discussed controversially. The aim of this study was to assess the effect of PRP in combination with autologous cancellous graft on bone defect healing in a critical metaphyseal long bone defect. A critical size defect in the tibial metaphysis of 16 mini-pigs was filled either with autologous cancellous graft as control group or with autologous cancellous graft combined with autologous PRP. Compared to native blood platelets were enriched about 4.9-fold in the PRP. After 6 weeks, the specimens were assessed by X-ray and histological evaluation. Histomorphometrical analysis revealed that the area of new bone was significantly higher in the PRP group concerning the central area of the defect zone (p < 0.02) as well as the cortical defect zone (p < 0.01). All defects showed substantial new bone formation, but only defects of the PRP group regenerated entirely. The PRP group was superior to the control group even in the semi-quantitative assessment of the osseous bridging in both observed areas of the defect. Within the limits of the present study it could be demonstrated that PRP combined with autologous cancellous graft leads to a significantly better bone regeneration compared to isolated application of autologous cancellous graft in an in vivo critical size defect on load-bearing long bones of mini-pigs.     

组织工程骨修复节段性骨缺损的实验研究

目的 探讨用多孔β-磷酸三钙生物陶瓷（β-tricalcium phosphate,β-TCP）与自体骨髓问充质干细胞（autologous bone marrow mesenchymal stem cells,MSC）构建组织工程骨修复节段性骨缺损的效果。方法 在羊左跖骨中段形成21mm长的骨缺损,实验组植入组织工程骨;对照组单纯植入β-TCP;空白组骨缺损不作处理。术后1、3、6个月分批处死动物,缺损区行放射学、组织学、生物力学和扫描电镜等检测。空白对照组6个月取材。结果 实验组,骨缺损部位新生类骨样组织、编织骨和板状骨出现的时间都较对照组早,并且不经软骨介导即能直接成骨,而对照组以“爬行替代”方式修复骨缺损。放射学和生物力学检测显示术后6个月实验组骨缺损几乎完全修复,对照组部分修复,而空白组未愈合。结论 组织工程骨能加速骨缺损愈合的速度,其修复过程可超越“爬行替代”阶段;组织工程骨是治疗节段性骨缺损的一种较好选择方式。     

Augmentation of demineralized bone matrix (DBM) mineralization by a synthetic growth factor mimetic.

These studies evaluated whether F2A4-K-NS, a peptide mimetic of FGF-2, could augment ectopic bone production following the subcutaneous implant of human demineralized bone matrix (DBM). DBM was formulated into a gel with and without F2A4-K-NS, and injected subcutaneously into athymic rats. After 28 days the resultant tissue was excised and fixed. The tissue was examined with soft X-rays and microcomputerized tomography (micro-CT), and by histological methods. Inclusion of F2A4-K-NS with DBM resulted in an increased mineral deposition as determined by soft X-ray and micro-CT analysis and von Kossa staining. DBM-containing tissues showed extensive mineralization compared to the carrier alone, which was poorly mineralized. The mineralization was qualitatively and quantitatively the most extensive in the samples containing F2A4-K-NS plus DBM. Additionally, the highest amount of von Kossa staining for calcium was observed in tissues from animals that had received DBM plus F2A4-K-NS. In these studies, 100 ng of peptide per 0.2 mL of injectable DBM gel generated the most optimal results. The synthetic peptide F2A4-K-NS augmented DBM-induced ectopic mineralization in athymic animals.     

Efficacy comparison of Accell Evo3 and Grafton demineralized bone matrix putties against autologous bone in a rat posterolateral spine fusion model

Background Context

Spinal fusion procedures are intended to stabilize the spinal column for a multitude of disorders including abnormal curvature, traumatic instability, degenerative instability, and damage from infections or tumors. As an aid in the bone healing response, bone graft materials are used to bridge joints for arthrodesis and promote unions in pseudoarthrosis. Currently, the gold standard for stabilizing fusion masses in spinal procedures involves using the osteogenic, osteoinductive, and osteoconductive properties of autologous iliac crest corticocancellous bone. However, considerable morbidity is associated with harvesting the autologous graft. Donor site complications including infection, large hematomas, and pain have been reported at rates as high as 50% (Boden and Jeffrey, 1995). Biologically, the rate of bone repair dictates the rate at which the fusion mass will unite under autologous graft conditions.

The effect of a composite of polyorthoester and demineralized bone on the healing of large segmental defects of the radius in rats.

The effect of a composite of demineralized bone mixed with polyorthoester on the healing of large segmental defects in the rat radius was studied. Sixty male Wistar rats were divided into four groups, A through D, and an osteoperiosteal diaphyseal defect of 50 per cent of the length of the bone was made in the right radius of each rat. In Group A, the defect was filled with polyorthoester and demineralized bone; in Group B, demineralized bone; and in Group C, polyorthoester. No material was implanted in the defects in the Group-D rats. The rats were killed fifty days postoperatively. The formation of bone in the defects was quantified with computer-assisted measurements of the area on radiographs. The host-tissue response was evaluated with light microscopy. Defects that had been filled with the composite of polyorthoester and demineralized bone or with demineralized bone alone showed regeneration of bone corresponding to 93.6 and 77.6 per cent of the area of the defect, respectively. Defects that had no implant or that had been filled with polyorthoester alone showed significantly less formation of bone. No inflammation was seen with light microscopy, and only traces of the polyorthoester could be detected in the defects that had been filled with the composite or with polyorthoester alone.     

Frontal sinus repair with free autologous bone grafts and fibrin glue

BACKGROUND: The authors describe a technique for repairing the frontal sinus with autologous bone grafts removed during craniotomy and fibrin glue. METHODS: This technique was used in 12 patients who underwent craniotomy for aneurysms (n = 9), brain tumors (n = 2), and acute epidural hematoma (n = 1). RESULTS: The repair was successful in all cases. There were no instances of postoperative infection or leakage of cerebrospinal fluid. No complications from the repair have occurred over a mean follow-up of 51 months. CONCLUSION: This technique is simpler than others used to seal a frontal sinus.     

Use of chemically extracted muscle grafts to repair extended nerve defects in rats.

Nerve regeneration, measured as axonal outgrowth, Schwann cell migration, macrophage invasion, and neovascularisation, was compared after repair of a 15 mm gap in rats' sciatic nerves using autologous muscle grafts made acellular either by freezing and thawing or by chemical extraction. Both extracted and freeze-thawed acellular muscle grafts could be used to bridge the defect. However, axons and Schwann cells, as shown by immunohistochemical staining for neurofilaments and S-100 protein, respectively, grew faster into the extracted muscle grafts than into the freeze-thawed acellular muscle grafts and somewhat more axons were observed in the former graft. There were no significant differences between the two graft types with respect to neovascularisation as showed by staining for endothelial alkaline phosphatase, and limited differences concerning invasion of macrophages (ED1 and ED2) as detected by immunocytochemistry. The results showed that chemically extracted muscle grafts could be used to bridge an extended nerve defect and that such grafts in some aspects were superior to freeze-thawed muscle grafts for extended gaps.     

Vascularized fibular grafts for the reconstruction of segmental tibial bone defects

Free vascularized fibular grafts were employed in seven patients with large tibial defects following trauma or resection of tumour. All patients were followed for more than 5 years. Tibial union and excellent functional results were achieved in all seven patients. Free vascularized fibular transfer seems to be an effective method of treatment for massive segmental bone defects.