骨形态发生蛋白在异体骨段移植愈合中的表达及临床意义

目的：研究骨形态发生蛋白（BMP）在异体骨段移植愈中的表达及临床意义。方法：采用新西兰大白兔股骨中段切除1．5cm骨干和骨膜实验动物模型。方法：36只兔随机分实验组和对照组。实验组植入深低温保存的异体骨,对照组植入自体新鲜骨,均用髓内针固定,分别于术后第1、2、3个月用免疫组织化学染色法观察BMP在异体骨愈合过程的表达情况,结果：深低温保存的同种异体骨移植愈合BMP表达与体骨相似,移植骨段BMP表达阴性,新生骨及其周围类基质表达阳性。新生编织骨BMP表达活跃,成熟板层骨BMP表达减弱（P＜0．01）。结论：异体骨移植愈合中骨吸收和骨诱导是同时,骨诱导在异体骨愈合早期发挥了重要作用。     

长段同种异体骨与自体活骨复合移植的实验研究

目的 研究长段同种异体骨与带血管腓骨套叠式复合骨移植体的愈合机制和规律。方法 采用健康成年杂种犬36只胫骨结节下切除3．0cm骨干和骨膜实验动物模型。随机分为实验组和对照组。实验组植入深低温保存的同种异体骨与带血管自体腓骨，对照组仅植入深低温保存的同种异体骨，均用7孔93cmAO加压钢板内固定及石膏外固定。术后1、2、3、4个月分别行X线摄片、ECT检查、大体标本及组织学观察。结果 X线示实验组较同时期对照组异体骨吸收、新骨形成明显，第4个月实验组宿主骨一异体骨接合部愈合率83．3％，对照组未愈合或不愈合。ECT检查：实验组较同期对照组骨代谢活跃，但变化规律相似，均为术后1、2个月活跃，于第2个月达高峰，第3、4个月呈下降趋势。组织学观察：实验组较同期对照组异体皮质骨髓腔内壁及哈佛管内的内吸收、成骨活动显著增强。结论 长段同种异体骨与带血管自体腓骨复合移植修复骨缺损效果良好，带血管自体腓骨能促进长段同种异体骨的血管化，加速其爬行替代过程。     

大段同种异体骨移植愈合的实验研究

目的研究大段同种异体骨移植愈合过程和特点。方法采用新西兰大白兔股中段切除１．５ｃｍ骨干和骨膜实验动物模。将３６只随机分成实验组和对照组。实验组植入深低温保存的同种异体骨,对照组植入自体新鲜骨,均用直径３ｍｍ的髋内针固定,于术后第１、２、３个月分别行Ｘ线摄片、ＥＣＴ、大体标本、组织学观察（四环素荧光标记,ＨＥ染色）以色ＢＭＰ免疫组织化学染色。结果深低温保存的同种异体骨移植愈合与自体骨相似,ＥＣＴ显示     

自体与同种异体复合骨移植中腓骨肌袖自然转归的实验研究

目的研究带血管自体腓骨与同种异体骨复合移植术后，腓骨肌袖的自然转归及其规律。方法采用健康成年杂种犬36只．于双侧后肢胫骨结节下切除3．0cm长胫骨骨干、骨膜，制作骨缺损实验动物模型，随机分成实验组和对照组。实验组植入深低温保存的同种异体骨与带血管自体腓骨，对照组植入深低温保存的同种异体骨均用7孔93mm长AO加压钢板内固定及石膏外固定。术后1、2、3、4个月分别行X线摄片、ECT检查、大体标本及组织学观察。结果X检查显示实验组较对照组异体骨吸收、新骨形成明显。第4个月实验组宿主骨-异体骨接合部愈合率83.3％，对照组未见愈合。ECT检查：实验组较对照组骨代谢活跃，但变化规律相似，均为术后1、2个月活跃，于第2个月达高峰，第3、4个月呈下降趋势.组织学观察：实验组较对照组异体骨髓腔内壁及哈弗管内的骨吸收、成骨活动显著增强，至第4个月，异体骨髓腔内壁与腓骨之间充满环形骨痂，并呈成熟至不成熟明显的阶梯状排列．靠近异体骨髓腔内壁骨痂较成熟，由大量成熟骨细胞组成。近腓骨侧骨痂较不成熟，主要由软骨细胞、骨细胞组成，异体骨髓腔内带血管蒂腓骨周围肌袖的肌纤维基本消失。结论带血管自体腓骨与同种异体骨复合移植术后，腓骨周围肌袖的自然转归是骨化。     

自固化磷酸钙复合BMP及同种异体骨修复兔股骨大段骨缺损

[目的] 观察一种新型自固化磷酸钙（CPC）复合BMP与同种异体骨修复兔股骨节段性骨缺损的效果，为临床复合应用大段同种异体骨移植提供参考。[方法] 54只新西兰大白兔随机分成3组，于一侧股骨中上段造成2cm长皮质骨缺损模型，分别进行：A组复合BMP与CPC的新鲜冷冻同种异体骨移植；B组单纯新鲜冷冻同种异体骨移植；C组自体大段骨移植。移植骨均用直径3mm三棱髓内针固定。于术后4、8、12周，进行影像学、组织学检查，对比各组移植骨愈合过程与修复效果。[结果] CPC复合BMP大段同种异体骨移植早期骨修复效果优于单纯异体骨移植（P〈0．01），与自体骨移植修复效果相似，至12周3组均达骨性愈合，以A组及C组骨修复塑形较好。CPC复合BMP组骨痂量较多，分布于移植骨与宿主骨结合部及移植骨周围，形成皮质骨外骨桥，并较早在异体骨外表面形成破骨与成骨，异体骨内哈佛氏管扩大，衬垫细胞、成骨细胞、破骨细胞及血细胞较其它组多。CPC随着新骨的形成及改建塑形逐步缓慢降解。[结论] CPC复合BMP对大段同种异体骨移植的愈合及替代有增强和促进作用。     

同种异体骨移植生物学

同种异体骨移植生物学孙磊综述胡蕴玉，宁志杰审校同种异体骨是临床上常用的替代自体骨移植材料，但同种异体骨移植可诱发宿主产生免疫排异反应，且目前临床上多采用经冷冻、冻干或化学处理的同种异体骨，其细胞成份多已坏死，因此同种异体骨移植在与宿主愈合过程中的表现...     

组织工程化同种异体骨移植修复骨缺损

目的解决骨缺损修复时自体骨移植存在修复材料来源有限,异体骨移植又为爬行替代,存在愈合慢、假关节率高的问题。方法以兔骨膜成骨细胞为种子细胞,经分离、体外培养、传代,再粘附于冷冻干燥表面脱钙同种异体骨,共同复合培养,制作兔胫骨缺损,分异体骨移植组(对照组)、组织工程化异体骨移植组,术后2、4、6周各处死2只兔子,大体观测骨痂大小及硬度;苏木精-伊红染色,光镜观察细胞在材料上的生长情况,了解其愈合快慢及质量。结果与对照组比较,实验组炎性明显较轻,细胞生长活跃,缺损愈合快。结论组织工程化同种异体骨移植能解决骨缺损修复时自体植骨材料来源有限,特别是在小儿及骨缺损大时修复材料的来源问题;同时,植入的异体骨又具有支架及自体成骨细胞活性,使植入的异体骨愈合加快,克服其愈合慢、假关节率高的问题。     

同种异体骨移植的研究进展

同种异体骨移植是目前临床广泛使用于治疗各种骨缺损和促进脊柱融合的方法。根据处理方式的不同,同种异体骨可以分为：新鲜异体骨、深冻骨、冷冻干燥骨（fresh frozen allograft, FFA）和脱钙骨基质（demineralized bone matrix, DBM）。同种异体骨与新鲜的自体骨的愈合机制有着本质不同,其主要依靠“爬行替代”实现与宿主骨的融合,因此愈合速度慢、愈合质量差,容易发生骨不连和移植骨骨折,故存在较高的失败率。而复合生长因子、复合间充质干细胞以及红骨髓等方法可以提高异体骨愈合的速度。利用组织工程的原理与方法,采用复合移植的方法使异体骨得到活化,是今后异体骨移植研究与应用的发展方向。     

大段同种异体骨移植重建四肢骨大段骨缺失

[目的] 探讨同种异体骨移植对大面积骨缺失的治疗.[方法] 骨缺失的修复几个世纪以来一直是骨外科工作者不断研究的重要课题.自体骨移植虽然得到普遍认同,但大面积的骨缺失却无法取得足够的自体骨,而人体同种异体骨移植材料和自体骨非常相近,它具有人骨的三维孔隙结构、更好的材料学和生物学特性,并在骨传导和骨诱导能力上有更强优势.但是如何将大段骨缺失用同种异体骨移植,降低移植骨宿主炎性反应及免疫排斥,完成骨诱导、骨传导以及移植骨逐步被自体骨替代的过程,自2000年5月-2004年7月作者收治了共3例四肢骨大段缺失的病人,将不同节段的、长度分别为6～12 cm的同种异体骨进行移植,同时进行了有效固定和抗免疫排斥处理.[结果] 移植均获得成功,每位患者随访2年以上,最长随访3年,患者复诊时x线片显示移植骨逐步被自体骨替代,患肢功能恢复正常.[结论] 经有效地固定和抗免疫排斥处理的大段同种异体骨的移植,能使肢体大段骨缺损重建.     

慢速梯度降温冷冻保存同种异体骨软骨移植治疗膝关节全层软骨缺损(附三例报告)

目的总结冷冻保存同种异体骨软骨移植物治疗3例膝关节全层骨软骨缺损的手术方法及疗效。方法应用梯度降温冷冻保存的6枚同种异体骨软骨移植物治疗3例膝关节全层骨软骨缺损,2例在关节镜下同种异体骨软骨移植,1例行关节切开移植。膝关节股骨髁关节软骨全层缺损平均面积2.16 cm2。所有患者在手术后第1个月、第3个月时进行膝关节MRI检查,了解移植物与周围骨软骨组织的愈合情况。并于门诊复查时进行Brittberg-Peterson膝关节功能评分,了解功能恢复情况。结果随访4～6个月,平均4.7个月。所有患者术后疼痛消失;无排异反应发生。术后3个月时,MRI检查示术后移植物与宿主软骨下骨整合良好,移植软骨组织结构与内部信号良好。Brittberg-Peterson评分术后6个月比手术前明显降低。结论经梯度降温冷冻保存的同种异体骨软骨移植治疗膝关节软骨缺损早期效果满意。     

异体骨关节移植后骨愈合的X线形式及影响因素

目的探讨肢体恶性肿瘤接受大段同种异体骨关节移植后和异体骨愈合在X线的表现及影响因素，以改进手术方法。方法1992年5月～1999年3月，对收治的90例中可纳入统计的85例骨恶性肿瘤在手术切除长段骨关节后，应用不同内固定方式进行异体骨关节移植，其中16例保留髁部关节面的异体骨段移植，57例异体关节移植，9例复合异体骨段人工髋关节置换，3例膝关节置换。术后平均随访2年9个月，以X线片表现判定骨愈合方式，依据Enneking肢体恶性肿瘤保肢术后的肢体功能标准，评价手术结果。结果85例101处异体骨与自体骨接合部有91处达到临床骨愈合。根据X线片表现特征，异体骨与自体骨间有4种愈合方式，其中以断端周围形成外骨痴、同时植骨间隙逐渐消失最多见；内固定不牢固是引起术后骨不愈合的主要原因；异体骨周围软组织覆盖、血供差及大段异体骨移植后诱发的免疫排异反应等可能影响骨愈合；远离异体骨与自体骨结合部的肿瘤复发或感染、不同长度的异体骨对骨愈合无肯定的负作用；选用牢固的髓内固定、断端周围植骨及采用骨膜袖套技术可减少术后骨不愈合的发生。结论大段异体骨关节移植后骨愈合有不同的X线片表现形式。手术设计应为异体骨提供充足的血液供应、牢固的内固定支撑和完善的软组织覆盖。     

复合骨移植修复骨肿瘤切除后大段骨关节缺损

目的 报道复合骨移植修复骨肿瘤切除后大段骨关节缺损的临床疗效。方法 2001年1月-2002年12月应用带监测皮岛的自体腓骨与大段同种异体深低温冷冻骨关节复合移植修复骨肿瘤切除后大段骨关节缺损10例。结果 10例均得到随访，随访时间5～24个月。移植的自体腓骨长度最长28cm，最短15cm。8例在术后3个月即有影像学骨性愈合，10例均于术后半年完全负重和邻近关节自由活动，术后超过1年的5例均已拆除内固定，术后1年均完全愈合。结论 带监测皮岛的自体腓骨与大段同种异体深低温冷冻骨关节复合移植是修复骨肿瘤切除后大段骨关节缺损的有效且可靠的方法，可用于骨肿瘤保肢术中。     

In vivo study on the healing of bone defects treated with bone marrow stromal cells, platelet-rich plasma, and freeze-dried bone allografts, alone and in combination.

The repair of confined trabecular bone defects in rabbits treated by autologous bone marrow stromal cells (BMSC), platelet-rich plasma (PRP), freeze-dried bone allografts (FDBA) alone and in combination (BMSC + PRP; FDBA + BMSC; FDBA + PRP; FDBA + PRP + BMSC) was compared. A critical size defect was created in the distal part of the femurs of 48 adult rabbits. Histology and histomorphometry were used in the evaluation of healing at 2, 4, and 12 weeks after surgery. The healing rate (%) was calculated by measuring the residual bone defect area. Architecture of the newly formed bone was compared with that of bone at the same distal femur area of healthy rabbits. The defect healing rate was higher in PRP + BMSC, FDBA + PRP, FDBA + BMSC, and FDBA + PRP + BMSC treatments, while lower values were achieved with PRP treatment at all experimental times. The highest bone-healing rate at 2 weeks was achieved with FDBA + PRP + BMSC treatment, which resulted significantly different from PRP (p < 0.05) and BMSC (p < 0.05) treatments. At 4 weeks, the bone-healing rate increased except for PRP treatment. Finally, the bone-healing rate of FDBA + PRP, FDBA + BMSC, and FDBA + PRP + BMSC was significantly higher than that of PRP at 12 weeks (p < 0.05). At 12 weeks, significant differences still existed between PRP, BMSC, and FDBA groups and normal bone (p < 0.05). These results showed that the combination of FDBA, BMSC and PRP permitted an acceleration in bone healing and bone remodeling processes.     

Repair of critical long bone defects using frozen bone allografts coated with an rhBMP-2-retaining paste

Background

Massive frozen stocked allogeneic bone grafts are often used to reconstruct large bone defects caused by trauma or tumor resections. However, the long-term failure rate of such massive allografts was reported to be 25% because of infection, fracture, and nonunion. In this study, we evaluated the ability of a recombinant human bone morphogenetic protein (rhBMP)-2-retaining paste to promote the osteogenic potential of frozen stocked allogeneic bone grafts to repair intercalated femoral shaft defects in a rat model.

Methods

After confirming the transplantation intolerance between two rat strains (Wistar and Lewis) by skin transplantation from Lewis rats to Wistar rats, an 8-mm-long bone segment was removed from the Wistar rats, and a frozen stocked allograft coated with the rhBMP-2-retaining paste from the Lewis rats was placed into the defect and subjected to intramedullary fixation with an 18-gauge injection needle pin. The allografted femurs were evaluated by radiographic, histologic, and biomechanical examinations at specified time points.

Results

The results revealed successful repair of critical-size cortical bone defects by implanting frozen stocked allografts coated with the rhBMP-2-retaining synthetic biodegradable carrier paste from an immunologically intolerant host.

Conclusions

This experimental study suggest that allogeneic bone grafting in combination with rhBMP-2 and its local delivery system may represent an innovative approach to the reconstruction of bone defects.     

A Bioactive Coating Enhances Bone Allografts in Rat Models of Bone Formation and Critical Defect Repair

Bone allografts are inferior to autografts for the repair of critical‐sized defects. Prior studies have suggested that bone morphogenetic protein‐2 (BMP‐2) can be combined with allografts to produce superior healing. We created a bioactive coating on bone allografts using polycondensed deoxyribose isobutyrate ester (PDIB) polymer to deliver BMP‐2 ± the bisphosphonate zoledronic acid (ZA) and tested its ability to enhance the functional utility of allografts in preclinical Wistar rat models. One ex vivo and two in vivo proof‐of‐concept studies were performed. First, PDIB was shown to be able to coat bone grafts (BGs). Second, PDIB was used to coat structural allogenic corticocancellous BG with BMP‐2 ± ZA ± hydroxyapatite (HA) microparticles and compared with PDIB‐coated grafts in a rat muscle pouch model. Next, a rat critical defect model was performed with treatment groups including (i) empty defect, (ii) BG, (iii) collagen sponge + BMP‐2, (iv) BG + PDIB/BMP‐2, and (v) BG + PDIB/BMP‐2/ZA. Key outcome measures included detection of fluorescent bone labels, microcomputed tomography (CT) quantification of bone, and radiographic healing. In the muscle pouch study, BMP‐2 did not increase net bone volume measured by microCT, however, fluorescent labeling showed large amounts of new bone. Addition of ZA increased BV by sevenfold (p < 0.01). In the critical defect model, allografts were insufficient to promote reliable union, however, union was achieved in collagen/BMP‐2 and all BG/BMP‐2 groups. Statement of clinical significance: These data support the concept that PDIB is a viable delivery method for BMP‐2 and ZA delivery to enhance the bone forming potential of allografts. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2278–2286, 2019     

Histomorphometric description of allograft bone remodeling and union in a canine segmental femoral defect model: a comparison of rhBMP-2, cancellous bone graft, and absorbable collagen sponge.

The purpose of this study was to determine the effect of recombinant human bone morphogenetic protein type 2 (rhBMP-2) on the histomorphometry of femoral allograft-host bone union and allograft remodeling. A 6 cm mid-diaphyseal femoral defect was created and filled with an allograft stabilized with an interlocking nail in 21 dogs. Dogs were randomly divided into three equal groups and the allograft-host bone junctions and the mid-diaphyses of the allografts were treated with either an absorbable collagen sponge (ACS) loaded with rhBMP-2 (BMP group), an autogenous cancellous bone graft (CBG group), or ACS loaded with buffer solution (ACS group). All dogs received daily tetracycline until sacrifice at 24 weeks to label new bone formation. Histomorphometric analyses on sections of proximal and distal allograft-host bone junctions and the mid-diaphyseal portion of allografts were performed using fluorescent and regular light microscopy. Analyses of the host bone and junctions between allograft and host bone revealed significantly greater new bone formation and larger osteon radii in the BMP group compared to CBG and ACS groups and contralateral intact bone. Porosity in CBG and ACS groups was significantly higher than in the BMP group, which had similar values to intact bone. In transverse sections of allografts, the largest pore diameters were present in the CBG group. Based on all parameters measured, significantly higher bone turnover occurred in the outer cortical area of the allograft in all groups as compared to the inner cortical and mid-cortical areas. New bone formation and osteon radius/osteon width in allografts were similar for all three groups. Higher porosity and larger pore diameters in the CBG and ACS groups suggested higher bone resorption versus formation in these groups compared to the BMP group. The results of this study reveal more balanced allograft bone resorption and bone formation in the BMP group, with greater resorptive activity in the CBG and ACS groups. However, neither rhBMP-2 nor autogenous bone graft increased allograft incorporation when compared to the negative control (ACS group).