人工骨腰椎后外侧融合过程中BMP基因的表达

目的研究利用人工骨做脊柱后外侧融合时局部BMP的表达情况,探讨人工骨在此过程中是否具备骨诱导作用。方法选用36只健康成年雄性新西兰白兔,制作L4、L5双侧横突间植骨融合模型,一侧采用磷酸钙人工骨(CPC),另一侧采用自体骨作为对照。按术后动物不同处死时间(0、2、4d、1、2、3、4、5、6、10周、6、10个月)随机平分为12组。采用RTPCR法检测融合组织BMP2mRNA、BMP4mRNA的表达水平。结果CPC材料内部在融合的各个时间段均未检测到BMP2mRNA和BMP4mRNA的表达。与紧密结合的植骨床及融合交界面中BMP2mRNA和BMP4mRNA的表达水平随时间变化均没有明显的增高,与自体骨相比,CPC融合过程中不同时间段内BMP2mRNA、BMP4mRNA的表达水平均明显低于自体骨(P<0.05)。结论单纯利用CPC做脊柱融合时,局部缺乏BMP的有效表达,可能导致融合失败率的增加。     

大鼠脊柱融合模型中BBP增强BMP-2的骨诱导作用

[目的]验证在大鼠脊柱融合模型中BBP对于rhBMP-2骨诱导作用的影响。[方法]采取Lewis大鼠的脊柱后外侧横突间融合模型,在胶原海绵为载体的rhBMP-2中加入BBP并减少rhBMP-2的用量,测试两种不同剂量的BBP(500 ug和1 000 ug)有或无低剂量的rhBMP2(1 ug)时的骨融合效果,并与单纯的低剂量rhBMP-2(1 ug)组相对比。融合效果采用手工评估,影像学评分,Micro-CT评估和组织学评估4种方法。[结果]BBP本身不管是低剂量还是高剂量均不能诱导骨融合。BBP复合低剂量BMP-2不能完全取得与高剂量BMP-2完全相同的效果,但可以减少BMP-2的用量。加入BBP的低剂量BMP-2组显然较低剂量BMP-2组融合率高,而且与高剂量BMP-2组的融合率相近,而且BBP的低剂量BMP-2组显然较低剂量BMP-2组融合的要早。[结论]在大鼠的脊柱融合模型中,BBP本身不管是低剂量还是高剂量均不能诱导骨融合。BBP可以增强BMP-2的骨形成作用,提高融合率,降低BMP-2的使用剂量以及减少了剂量相关性副作用的发生率,但不能取得与高剂量BMP-2完全相同的效果。BBP可以减少脊柱融合所需的时间和提高形成骨的质量。进一步的研究可以优化BBP和BMP-2的剂量,从而为以后的临床手术应用中取得更好的融合效果。     

复合骨在兔腰椎融合过程中相关基因表达调控的影响

目的 观察复合骨即重组人骨形态发生蛋白-2(rhBMP-2)/异体骨不同时间点融合骨组织中BMP-2、血管内皮生长因子(VEGF)的表达.方法 将新西兰大白兔60只随机分为3组,在L5、L6横突间行后路植骨融合术,分别植入复合骨条、自体骨条及异体骨条,于术后第1、2、3、4、5周取融合标本,用实时荧光定量逆转录聚合酶链反应(real time RT-PCR)分析内源性BMP-2和VEGF基因水平的变化.结果 术后第3周,复合骨组BMP-2为(5.3519±1.0384),VEGF为(0.9257±0.2534),均达到峰值且高于异体骨组和自体骨组(P<0.05),之后则缓慢下降.第4周后,内源性BMP-2表达仍保持较高水平,但VEGF的水平与自体骨组和异体骨组差异无统计学意义(P>0.05).结论 复合骨能有效地诱导内源性BMP-2和VEGF的表达,促进了成骨效应.     

高能震波促进缺血性坏死股骨头BMP-2的表达

[目的]观察高能震波对缺血性坏死股骨头骨形态发生蛋白2(BMP-2)表达的影响,探讨高能震波治疗股骨头缺血性坏死的作用机制.[方法]健康雄性新西兰白兔38只,3.0～4.0 kg,平均3.3 kg.联合应用甲基强的松龙和内毒素6周诱发早期股骨头缺血性坏死的动物模型.所有实验兔左后腿作为治疗侧,采用能流密度0.26 mJ/mm~2,频率1 Hz,冲击量为2 000次的高能震波治疗,右后腿作为对照侧,不予治疗.分别于治疗后24 h和第1、2、4、8、12周各取6只动物处死,取股骨头标本行实时荧光定量PCR、免疫组化染色,检测BMP-2的表达.[结果]高能震波治疗显著增加了兔股骨头骨组织中BMP-2 mRNA的表达,治疗侧股骨头BMP-2 mRNA的表达在治疗后第24 h以及第1、2、4、8周显著高于对照侧,在治疗后第1周BMP-2 mRNA的表达最高.高能震波治疗后4、8和12周,治疗侧股骨头BMP-2平均染色面积百分比显著高于对照侧(P<0.01,P<0.01和P<0.01).高能震波治疗后4、8和12周,治疗侧股骨头BMP-2平均吸光度显著高于对照侧(P<0.01,P<0.01和P<0.01).[结论]高能震波治疗能有效促进缺血性坏死股骨头BMP-2的表达,可能有助于增加股骨头的骨生成,加速股骨头坏死的修复.     

重组人BMP-2缓释作用于基质血管成分细胞促进大鼠脊柱融合的实验研究

目的将重组人BMP-2(recombinant human BMP-2,rh BMP-2)缓释作用于新鲜分离的大鼠基质血管成分细胞(stromal vascular fraction cells,SVFs),移植到大鼠腰椎横突后外侧,观察其促进脊柱融合的效果。方法取健康4月龄SD大鼠双侧腹股沟区皮下脂肪,采用Ⅰ型胶原酶消化法提取SVFs。通过仿生磷灰石涂层方法,将rh BMP-2与β-磷酸三钙(β-tricalcium phosphate,β-TCP)通过共价键结合制成缓释载体,通过BCA法测定其缓释效应。将32只大鼠随机分成4组,每组8只。采用L_4、L_5横突去皮质化方法制备大鼠腰椎后外侧融合模型,分别于A、B、C、D组植入PBS+脱钙骨基质(decalcified bone matrix,DBX)、rh BMP-2/β-TCP缓释载体+DBX、SVFs+DBX和SVFs+rh BMP-2/β-TCP缓释载体+DBX。术后8周获取腰椎融合标本,进行手法判断和X线片观察评价脊柱融合情况,以及micro-CT评价脊柱融合情况,并分析骨密度(bone mineral density,BMD)及骨体积分数;行HE染色、Masson三色组织学染色,以及免疫组织化学染色检测骨钙蛋白(osteocalcin,OCN)。结果 2周时rh BMP-2/β-TCP缓释载体的rh BMP-2体外累计释放量为40%左右,起到缓慢释放效果;而未经仿生磷灰石涂层的对照组2周时几乎停止释放rh BMP-2。手法判断、X线片和micro-CT评估一致,显示D组成骨能力最强,达100%融合(8/8),之后依次为B组(75%、6/8)、C组(37.5%、3/8)、A组(12.5%、1/8)。Micro-CT分析示,D组BMD和骨体积分数均显著高于其余3组,B组显著高于A、C组,差异均有统计学意义(P0.05)。HE、Masson三色染色和OCN免疫组织化学染色示,D组有大量软骨细胞连接,伴有骨基质沉积、有活跃的成骨过程,类似长骨的矿化过程;B组的骨形成相对D组较弱;A、C组缺乏有效的新骨形成。结论新鲜分离的SVFs在rh BMP-2缓释作用下,显示出良好的骨生成能力,可有效促进脊柱融合,为临床应用提供理论基础。     

BMP-2在新型种植体骨界面表达变化的实验研究

目的：研究BMP-2在新型种植体一骨界面的表达。方法：通过动物体内的种植体种植试验，用免疫组织化学sp法观察骨形成蛋白-2（bone morphogenetic protein，BMP-2）在新型种植体一骨界面的表达变化。结果：从第2周起，随着观察时间的延长，BMP-2在新型种植体和对照组种植体的种植体-骨界面的表达逐渐减少。第2周时，新型种植体-骨界面的BMP-2平均灰度值高于对照组，其差别具有统计学意义（P〈0．01）。在其他时间组里，两种种植体一骨界面的BMP-2灰度值差别没有统计学意义（P〉0．05）。结论：新型种植体特殊的设计使其较圆柱状种植体更早形成骨性结合。     

体内负压技术对家兔颅骨修复及BMP-2 mRNA表达水平的影响

[目的]间歇性负压可以促进人骨髓间充质干细胞(bone marrow-derived stroma cells,BMSCs)向成骨细胞定向分化,上调成骨相关基因的表达水平。通过观察体内负压技术对兔颅骨骨孔修复过程及骨形态发生蛋白-2(bone morphogenetic protein-2,BMP-2)表达水平的影响,探讨负压技术在体内对骨组织修复作用。[方法]建立体内负压吸引干预动物模型,负压处2个骨孔为实验组,另外2个骨孔为对照组。对动物进行体内负压吸引技术干预(50 kPa,30 min/次,2次/d,间歇性负压干预1周)后,通过X线、骨密度观察其对家兔颅骨修复过程的影响,荧光定量RT-PCR检测BMP-2 mRNA的表达水平。[结果]术后2、4周实验组骨孔区X线阻射程度分别为(43.14±2.26)、(82.95±2.43),对照组分别为(25.13±2.12)、(51.49±2.37),差异有统计学意义(P<0.05);2周及4周实验组骨密度分别为(0.236±0.012)、(0.282±0.004),对照组分别为(0.174±0.005)、(0.213±0.009),两组相比差异有统计学意义(P<0.05);术后2、4周实验组BMP-2 mRNA的表达水平分别为(0.52±0.11)、(0.73±0.14),对照组分别为(0.29±0.07)、(0.36±0.09),两组相比差异有统计学意义(P<0.05)。[结论]体内负压技术可以上调BMP-2 mRNA表达水平,加速兔颅骨修复的进程,促进骨组织再生。     

探讨在复合肌肉骨膜瓣联合移植修复长段骨缺损中BMP-2的表达

目的:研究骨形态发生蛋白(BMP-2)在肌肉瓣加骨松质颗粒及骨髓(复合肌肉骨膜瓣)联合移植修复长段骨缺损中的表达.方法:实验采用新西兰大白兔24只,左右桡骨制成20mm的骨缺损模型,左侧桡骨骨缺损处用自体髂骨骨松质制成颗粒状和肱桡肌及股骨内骨髓混合后联合移植作为实验组,右侧做成骨缺损作为对照组,不做任何处理,任其自然生长.术后3d和1、2、4、6、8周后处死动物取材,进行HE及BMP-2多克隆抗体的免疫组化染色和BMP的cDNA探针原位杂交并在光镜下观察.结果:(1)实验组和对照组在术后3d时,均有炎症反应,未见BMP-2的表达,在以后几周时间内BMP-2的表达强度均强于对照侧.结论:在本实验中可以得出:(1)BMP-2是骨缺损修复过程中的一种重要生长因子,(2)本术式明显能缩短骨缺损修复的时间,为在临床中的应用提供理论依据.     

BMP-2基因给药修复实验性羊股骨头坏死

目的利用人BMP-2基因转染的自体骨髓间充质干细胞复合多孔β-磷酸三钙材料治疗股骨头坏死。方法对22只羊建立股骨头缺血性坏死模型。未治疗组4只;治疗组18只于3周后刮除坏死骨组织,右侧植入BMP-2基因转染的自体骨髓间充质干细胞和多孔磷酸三钙复合物(BMP-2组),左侧植入β-半乳糖苷酶(β-gal,作为对照基因)基因转染的自体骨髓间充质干细胞和多孔磷酸三钙复合物(β-gal组)。植入后第1、2、3周用ELISA方法测定植入局部的BMP-2蛋白表达水平。植入前、植入后6、10、16周取股骨头标本,观察骨长入情况,并对16周标本行骨形态计量学分析和影像学观察。未治疗组动物于造模后16周摄Χ线片行影像学观察。结果植入后1、2、3周BMP-2组在股骨头局部有BMP-2蛋白的高表达,明显高于β-gal组。植入前软骨下骨部位出现大量空骨陷窝,骨髓腔纤维化。植入后6、10、16周BMP-2组均有明显成骨,16周时坏死区被完全修复;β-gal组只有较少新骨形成,16周时坏死区仍多为纤维组织。BMP-2组新骨体积明显大于β-gal组。造模后16周未治疗组双侧股骨头塌陷;植入后16周β-gal组股骨头存在囊状密度减低区;BMP-2组股骨头形态规则,无塌陷。结论BMP-2基因转染的骨髓间充质干细胞与多孔β-磷酸三钙复合后可修复早期股骨头坏死。     

骨折端微动对骨形态发生蛋白-2表达的影响

目的 研究骨折端微动时轴向应力对骨形态发生蛋白-2（BMP-2）表达的影响。方法 72只新西兰大白兔分为微动组与固定组，利用免疫组化及原位杂交方法检测两组动物骨折端BMP-2蛋白及mRNA表达的不同。结果 BMP-2蛋白及mRNA表达于间质细胞、成骨细胞、成软骨细胞、骨细胞及骨基质。在骨折愈合过程早期高度表达，峰值位于骨折后14d，其后表达水平降低。BMP-2蛋白及mRNA染色阳性指数术后14、21、28d微动组大于固定组，差异有统计学意义（P〈0．05）。结论 骨折端微动时BMP- 2蛋白及mRNA表达在特定时间增强。     

Reduced expression of BMP-3 due to mechanical loading: a link between mechanical stimuli and tissue differentiation

Mechanical signaling and BMP expression appear to be involved in controlling the differentiation of cartilage in fracture repair, but the connection between mechanics and BMP signaling is not known. In this study of rats, we used a bone chamber to see how BMP gene expression was changed by a mechanical loading regime that induces cartilage formation in this model. We compared the still undifferentiated tissue in loaded and unloaded chambers in the same rat regarding the expression of TGFbeta-1, BMP-2, 3, 4, 5, 6, 7, CDMP-1, 2 and ALK-2 and 3 by using RT-PCR normalized against GAPDH. We found expression of TGFbeta-1, BMP-2 and 4 in all specimens, and BMP 5-7 and CDMPs in none. 1 week after loading started, BMP-3 was strongly expressed in the unloaded control specimens in 7 of 8 animals, but detectable in only I of the contralateral loaded ones. After 2 weeks of loading, the BMP-3 expression pattern was less clear, but with both time groups taken together, there was still less BMP-3 expression on the loaded side in 9 rats, more in 1 and no difference in 5 (p = 0.01). ALK-2 at 1 week was expressed in all specimens expressing BMP-3 and in none of the others. At 2 weeks, ALK-2 was expressed in all specimens. Thus, a loading regime, known to induce cartilage in this model, caused down-regulation of BMP-3 and ALK-2. The results are consistent with the view that BMP-3 inhibits differentiation, as recently described. This role appears to be linked to the ALK-2 receptor. Most importantly, the results indicate a link between mechanical signaling and BMP expression such that mechanically-induced down-regulation of the inhibiting BMP-3 enabled the induction of cartilage.     

基因修饰的组织工程骨联合带血管蒂骨膜移植修复长段骨缺损的研究

目的评价骨形态发生蛋白2（bone morphogenetic protein2,BMP-2）基因修饰的组织工程骨联合带血管蒂骨膜移植修复长段骨缺损的效果。方法分离培养兔骨髓基质干细胞,经BMP-2基因转染后复合异种骨支架体外构建基因修饰的组织工程骨（gene modified tissue engineering bone,GMB）。建立兔双侧桡骨缺损（长2.5cm）模型,采用5种方法修复。A组：GMB＋带血管蒂骨膜移植;B组：GMB＋血管束植入;C组：GMB＋游离骨膜移植;D组：GMB;E组：单纯支架。于术后第4、8、12周行X线、组织学、生物力学测定和微血管墨汁灌注等观察血管形成及成骨情况。结果①A组血运建立快,第8周时即可修复骨缺损,其修复机制包括膜内成骨和软骨成骨两种机制;②B组血管束发出分支向移植骨内长入,但中心区成骨缓慢,第12周时骨缺损得到完全修复;③C组第4周时游离骨膜成活并发出微小血管,第8周时形成薄层外骨痂,第12周时骨缺损基本修复;④D组在BMP-2基因诱导下成骨速度和质量优于E组,可在第12周时使骨缺损部分修复,但中心区呈＂空心＂现象;而E组第12周时形成骨不连,缺损区内被纤维组织填充。结论带血管蒂骨膜与BMP-2基因修饰的组织工程骨联合移植,既提供了血运又提供了骨膜成骨细胞,同时具有良好的骨生成、骨诱导和骨引导作用,是治疗节段性骨缺损较为理想的方法。     

Reduced expression of BMP-3 due to mechanical loading: A link between mechanical stimuli and tissue differentiation

Mechanical signaling and BMP expression appear to be involved in controlling the differentiation of cartilage in fracture repair, but the connection between mechanics and BMP signaling is not known. In this study of rats, we used a bone chamber to see how BMP gene expression was changed by a mechanical loading regime that induces cartilage formation in this model. We compared the still undifferentiated tissue in loaded and unloaded chambers in the same rat regarding the expression of TGFß-1, BMP-2, 3, 4, 5, 6, 7, CDMP-1, 2 and ALK-2 and 3 by using RT-PCR normalized against GAPDH. We found expression of TGFß-1, BMP-2 and 4 in all specimens, and BMP 5-7 and CDMPs in none. 1 week after loading started, BMP-3 was strongly expressed in the unloaded control specimens in 7 of 8 animals, but detectable in only 1 of the contralateral loaded ones. After 2 weeks of loading, the BMP-3 expression pattern was less clear, but with both time groups taken together, there was still less BMP-3 expression on the loaded side in 9 rats, more in 1 and no difference in 5 (p = 0.01). ALK-2 at 1 week was expressed in all specimens expressing BMP-3 and in none of the others. At 2 weeks, ALK-2 was expressed in all specimens. Thus, a loading regime, known to induce cartilage in this model, caused down-regulation of BMP-3 and ALK-2. The results are consistent with the view that BMP-3 inhibits differentiation, as recently described. This role appears to be linked to the ALK-2 receptor. Most importantly, the results indicate a link between mechanical signaling and BMP expression such that me chanically-induced down-regulation of the inhibiting BMP-3 enabled the induction of cartilage.     

Temporal and spatial expression profiles of BMP receptors and noggin during BMP-2-induced ectopic bone formation.

The mechanism of ectopic bone formation has not been clear. After BMP-2 implantation into the back muscles of 198 mice, expression of BMPR-1A, -2, and Noggin was increased during the early phase of the reaction. The results suggest that positive and negative feedback mechanisms modulate ectopic osteogenesis induced by this growth factor. INTRODUCTION: The expression of bone morphogenetic protein receptors (BMPRs) and Noggin during ectopic bone formation after implantation of BMP-2 into the back muscles of adult mice was investigated in this study. METHODS: One hundred ninety-eight male ddy mice were divided into groups and received either collagen disks containing BMP-2, collagen disks alone, or sham surgery with no disk implantation. Changes in the temporal and spatial expression profiles of BMPRs and Noggin were examined by Northern blotting, in situ hybridization, Western blotting, and immunohistochemistry. RESULTS AND CONCLUSIONS: In the BMP group, expression of BMPR-1A, -2, and Noggin mRNA and protein was enhanced 2-4 days after implantation in undifferentiated mesenchymal cells and regenerating muscle fibers located close to the BMP-retaining implants. On day 7, the expression was also observed in cartilage cells, and after day 14, in the osteoblastic cells around bone tissue. The level of expression peaked at day 4 after implantation and persisted at a much lower level during the bone forming process. No significant expression of BMPR-1B was detected at the mRNA and protein levels during the bone-forming reaction. In the BMP free control groups, a mild enhancement of BMPR-2 expression was also noted around the implant, but this was not observed for BMPR-1A, -1B, or Noggin. Upregulated expression of BMPR-1A, -2, and Noggin in undifferentiated mesenchymal cells and regenerating muscle fibers occurs during the early phase of BMP-2-induced bone formation. The coordinate expression of these positive and negative regulators of BMP signaling points to a potential regulatory mechanism for bone induction.     

The missing effect of human recombinant Bone Morphogenetic Proteins BMP-2 and BMP-7 in surgical treatment of aseptic forearm nonunion

IntroductionIn this cohort study, the surgical revision concept of open compression plating and autologous bone grafting with and without additional application of BMP for treatment of aseptic ulna and/or radius shaft nonunion was evaluated. The purpose was to evaluate the clinical and radiological outcome, and to determine any difference in osseous healing, range of time between revision surgery and bone healing, and postoperative complications between the cohort groups.Patients and methodsBetween 01/2005 and 03/2015, a prospective, randomised, controlled cohort study was performed in a Level I Trauma Centre. Forty-nine patients were treated with the diagnosis of aseptic diaphyseal ulnar and/or radial shaft nonunion using compression plating and autologous bone grafting. Additional biological augmentation using BMP-2 or BMP-7 was performed in 24 patients. Clinical and radiological follow-up was performed six weeks, three and six months after revision surgery in accordance to the system by Anderson.ResultsThe study group consisted of 38 men and 11 women with a median age of 44 years (range 19–77). Twenty-four out of 49 patients obtained compression plating either with autologous iliac crest bone grafting (11/24 patients) or cancellous bone grafting (13/24 patients) and additional application of BMP-2 (4/24 patients) or BMP-7 (20/24 patients). The remaining 25 patients did not receive any additional application of BMP, but autologous bone grafting. The median follow-up was 15 months (range 6–54 months). Forty-six out of 49 nonunion healed within 12 months after revision surgery with a median time to union of six months. The clinical outcome, as assessed using the system by Anderson, as well as osseous healing, duration of time interval between revision surgery and bone healing, and postoperative complications did not demonstrate significant differences between the cohort groups.DiscussionAtrophic/oligotrophic forearm nonunion healed irrespective of additional application of BMP combined with autologous bone grafting. For successful treatment, radical resection of fibrous nonunion tissue and internal compression plate fixation is required with the aim of achieving high degree of rigid stability. Also, correction of angular deformities, restoration of length, and precise axial alignment of the distal radio-ulnar joint are mandatory prerequisites to successfully achieve bone healing.     

Comparison of BMP-2 and combined IGF-I/TGF-ß1 application in a sheep cervical spine fusion model

Growth factors have proven to promote spine fusion. However, no comparative evaluation of growth factors in spinal fusion has yet been performed. The purpose of this study was to compare the efficacy and safety of combined IGF-I and TGF-ss1 application with BMP-2 application and autologous cancellous bone graft at an early time point in a sheep cervical spine fusion model. Thirty-two sheep underwent C3/4 discectomy and fusion. They were divided into four groups, according to their treatment: group 1, titanium cage ( n=8); group 2, titanium cage filled with autologous cancellous iliac crest bone grafts ( n=8); group 3, titanium cage coated with a poly-(D,L-lactide) (PDLLA) carrier including BMP-2 (5% w/w) ( n=8); group 4, titanium cage coated with a PDLLA carrier including IGF-I (5% w/w) and TGF-ss1 (1% w/w) ( n=8). Blood samples, body weight and temperature were analysed. Radiographic scans were performed pre- and postoperatively and after 1, 2, 4, 8 and 12 weeks. At the same time points, disc space height and intervertebral angle were measured. After 12 weeks, the animals were killed and fusion sites were evaluated using functional radiographic views in flexion and extension. Quantitative computed tomographic scans were performed to assess bone mineral density, bone mineral content and bony callus volume. Biomechanical testing was carried out and the values for range of motion, and neutral and elastic zone were determined. Histomorphological and histomorphometrical analysis were performed and polychrome sequential labelling was used to determine the time frame of new bone formation. The results showed that, in comparison to the group treated with the cage alone (group 1), the cage plus BMP-2 group (group 3) and the cage plus IGF-I and TGF-ss1 group (group 4) demonstrated a significantly higher fusion rate in radiographic findings, a higher biomechanical stability, a more advanced interbody fusion in histomorphometrical analysis, and an accelerated interbody fusion on fluorochrome sequence labelling. In comparison to the bone graft group (group 2), the BMP-2 (group 3) and IGF-I/TGF-ss1 group (group 4) showed significantly less residual motion on functional radiographic evaluation, higher bone mineral density of the callus and higher biomechanical stability in extension, rotation and bending. The BMP-2 group showed significantly less residual motion on functional radiographic evaluation and higher intervertebral bone matrix formation on fluorochrome sequence labelling at 9 weeks in comparison to the IGF-I/TGF-ss1 group. In contrast, the IGF-I/TGF-ss1 group showed a significantly higher bone mineral density of the callus than the BMP-2 group. In comparison to the autologous cancellous bone graft group, both growth factors (BMP-2 and combined IGF-I and TGF-ss1) significantly improved the biomechanical results of interbody fusion. No systemic side effects were observed for either growth factor. On the basis of these preliminary results, it would appear that combined IGF-I/TGF-ss1 application yields equivalent results to BMP-2 application at an early time point in anterior sheep cervical spine fusion.