Coral as graft in cervical spine surgery

The value of using biodegradable devices and particularly coral in cervical spine surgery is linked to the desire to supress the disadvantages of taking bone graft for arthrodeses (using the Robinson's technique), be it iliac, fibular or tibial. The chemical, microscopical, biomechanical and clinical study of coral since 1970 enabled us to show the value of a material whose structure resembles that of bone, degrading itself completely and being replaced by newly formed bone. Our first results in 37 cases confirm these data by studying the evolution of coral, the good clinical tolerance, its good radiological incorporation with no alteration of the static balance of the cervical spine. A literature review on the subject of the use of biodegradable devices shows the advantages and disadvantages of each explaining the reason for our choice.     

Posterolateral and anterior interbody spinal fusion models in the sheep

Posterolateral and anterior interbody spinal arthrodesis is a frequent procedure, but high nonunion rates are reported and harvesting autologous bone graft from the iliac crest significantly increases morbidity. Bone graft substitutes are an alternative, but to date clinical results are not conclusive. Bone substitutes can be organic or inorganic, biologic or synthetic. They can have osteoconductive properties, inductive properties or both. Animal experiments are essential to investigating bone substitutes using biomechanical and histologic methods not available in clinical studies. Few authors reported on instrumented anterior fusion models, but none used the sheep model. In the current study posterolateral and anterior interbody fusion models in sheep are described. Both models used instrumented fusions, applying porous mineral scaffolds, alone or mixed with bone. The surgical techniques are described step-by-step and potential difficulties are highlighted. Preliminary results are reported for the posterolateral fusion model using coralline graft substitutes. The coral granules mixed with locally harvested bone had fusion outcomes similar to pure autologous bone. The graft substitute showed marked resorption between 12 and 20 weeks. All fusions had bone cortex and good trabecular connectivity. Histologic evaluation suggests after 20 weeks nearly the entire surface of the substitute is covered with new bone. Porous mineral bone substitutes mixed with locally harvested autologous bone are thought to be a valid alternative for posterolateral fusions.     

Biomechanical evaluation and preliminary clinical experience with an expansive pedicle screw design

The advantages of pedicle screw fixation depend on their ability to retain bony purchase until the fusion mass is stable. Osteoporotic bone and removal and replacement of pedicle screws in revision procedures substantially reduce screw mechanical fixation strength and can lead to clinical failure. The objective of this study was to determine if an expansive pedicle screw design could be used to improve biomechanical fixation in bone of compromised quality. Axial mechanical pullout testing was performed on paired expansive and conventional pedicle screws placed in fresh, unembalmed cadaveric vertebrae. Bone mineral density measurements (made using a dual-energy X-ray absorption meter) were used to characterize bone quality. A preliminary clinical and radiographic evaluation of 14 patients was also performed at a minimum 2-year follow-up. The mean axial pullout force in bone of all qualities was increased 30% when the expansive pedicle screw design was used. This included an appropriate 50% increase in pullout force in bone of poor quality (low bone mineral density). The preliminary clinical and radiographic results were supportive of the biomechanical design rationale and mechanical testing. The results were similar to those expected for spinal instrumentation using pedicle screws, even though compromised bone was present in two thirds of the cases in which the expansive screw was used.     

脊柱骨巨细胞瘤的CT与MRI诊断

目的探讨脊柱骨巨细胞瘤的CT、MRI表现及其诊断价值。方法本组17例为经手术病理证实的脊柱巨细胞瘤患者,男13例,女4例,平均年龄49岁;临床与影像学资料齐全。分析病灶的影像学特征及其对诊断与鉴别诊断意义。结果17例脊柱巨细胞肿瘤患者中颈椎5例,胸椎7例,腰椎2例,骶椎3例;14例仅累及1个椎体,3,例累及2个椎体。本组患者X线片示：11例表现为椎体溶骨性破坏并具一定的膨胀性,6例表现为椎体不同程度的压缩。CT示：椎体破坏区无骨性成分存留。MRI示：T1 WI为较均匀中至低信号,T2 WI为较均匀高信号,病灶部分呈良性的硬化骨边缘,部分终板破坏形成软组织肿块。结论脊柱巨细胞瘤影像学表现不同于四肢巨细胞瘤,瘤内无孵确骨性成分存留;可分为膨胀型和压缩型,兼有良、恶性肿瘤的影像学特征,主要应与脊柱动脉瘤样骨囊肿及转移瘤相鉴别。     

A coralline hydroxyapatite bone graft substitute. Preliminary report

Experimental histologic and biomechanical studies were performed in 52 dogs by use of a bone substitute composed of hydroxyapatite converted from sea coral calcite. The results demonstrate some potentially useful practical applications. The material was totally incorporated in bone. Although initially too weak to tolerate physiologic stresses, once incorporated it becomes almost as strong as the native bone. Clinical experience with internal fixation of fractures with hydroxyapatite in 18 patients is encouraging.     

What bone graft substitutes should we use in post-traumatic spinal fusion?

Surgical treatment of spinal fractures consists of postural reduction and segmental arthrodesis, together with an eventual performance of spinal canal decompression. Spinal arthrodesis consists of the combination of a hardware system for mechanical stabilisation together with a biological substance for enhancement of bone formation. To date, autologous graft is the only biological substance demonstrated to possess osteogenic properties. Cancellous bone graft has greater cellular activity than cortical graft, whereas cortical graft is stronger. Consequently, according to biological and biomechanical properties of autograft, spinal posterior arthrodesis is better enhanced by cancellous autograft, whereas anterior interbody tricortical bone is more suitable for anterior fusion. Allograft does not cause harvesting complications as autograft does, and also its amount is theoretically unlimited; nevertheless the rate of bone fusion facilitated by allograft is far from that enhanced by autograft given that allograft has no osteoprogenitor cells. There is little evidence on the efficacy of demineralised bone matrix for spinal fusion. Bone morphogenetic proteins (BMPs) are in use in spinal surgery, but their exact role with respect to type, dose, and carrier, together with their cost-effectiveness, need further clinical delineation. Calcium phosphate compounds appear to be good as carriers; however, they have no osteoinductive or osteogenic properties. Current clinical literature seem to indicate their usefulness for bony fusion in spinal surgery, when combined with bone marrow aspirate or used as an extender for autologous bone graft. Age, length of fusion, location, and concurrent diseases should be definitive for fusion outcome; papers on spinal arthrodesis should neatly stratify these variables. Unfortunately, since that is not the rule, conclusions drawn from current literature are very unreliable. Autograft remains the gold standard, and cancellous bone is advisable in posterolateral approaches, whereas tricortical iliac crest autograft appears appropriate for interbody support. In longer segments, its expansion with BMPs looks safe at least. Basic knowledge has been achieved from animal experiments, and clinical application of the findings to humans should be done very cautiously; in any case, both anterior and posterior arthrodesis must be protected with instrumentation used according to appropriate biomechanical principles. A combination of failure of the correct graft together with proper instrumentation will result in poorer outcome, even if the right graft is used.     

同种异体骨板覆盖预防椎板切除术后硬膜外粘连临床应用

目的探讨同种异体骨板覆盖在预防椎板切除术后硬膜外粘连方面的疗效。方法对58例腰椎间盘突出或腰椎管狭窄患者,行全椎板切除,“H”形同种异体冻干辐照骨板覆盖。观察临床症状及CT、MR I表现。结果术后随访6个月~2.5年,CT、MR I椎管扩大,骨板无倾斜、移位,脊髓无压迫,无排异反应;术后椎管内容物形态良好,骨板两侧已与相邻接触骨组织融合,密度相等。结论同种异体冻干辐照骨板具有良好的生物相容性、生物力学性能和诱导成骨作用,是一种良好的硬膜外覆盖材料,能有效阻止硬膜外粘连,防止椎管术后再狭窄,可用于节段性椎管覆盖成型术。     

A biomechanical sorting of clinical risk factors affecting osteoporotic hip fracture

Osteoporotic fracture has been found associated with many clinical risk factors, and the associations have been explored dominantly by evidence-based and case-control approaches. The major challenges emerging from the studies are the large number of the risk factors, the difficulty in quantification, the incomplete list, and the interdependence of the risk factors. A biomechanical sorting of the risk factors may shed lights on resolving the above issues. Based on the definition of load-strength ratio (LSR), we first identified the four biomechanical variables determining fracture risk, i.e., the risk of fall, impact force, bone quality, and bone geometry. Then, we explored the links between the FRAX clinical risk factors and the biomechanical variables by looking for evidences in the literature. To accurately assess fracture risk, none of the four biomechanical variables can be ignored and their values must be subject-specific. A clinical risk factor contributes to osteoporotic fracture by affecting one or more of the biomechanical variables. A biomechanical variable represents the integral effect from all the clinical risk factors linked to the variable. The clinical risk factors in FRAX mostly stand for bone quality. The other three biomechanical variables are not adequately represented by the clinical risk factors. From the biomechanical viewpoint, most clinical risk factors are interdependent to each other as they affect the same biomechanical variable(s). As biomechanical variables must be expressed in numbers before their use in calculating LSR, the numerical value of a biomechanical variable can be used as a gauge of the linked clinical risk factors to measure their integral effect on fracture risk, which may be more efficient than to study each individual risk factor.     

Factors influencing stresses in the lumbar spine after the insertion of intervertebral cages: finite element analysis

Intervertebral cages in the lumbar spine have been an advancement in spinal fusion to relieve low back pain. Even though initial stability is accepted as a requirement for fusion, there are other factors. The load transfer and its effect on the tissues adjacent to the cage may also play an essential role, which is not easily detectable with experimental tests. In this study the effects of an intervertebral cage insertion on a lumbar functional spinal unit were investigated using finite element analyses. The influences of cage material, cancellous bone density and spinal loading for the stresses in a functional spinal unit were evaluated. Three-dimensional (3D) finite element models of L2-L3 were developed for this purpose. An anterior approach for a monobloc, box-shaped cage was modelled. Models with cage were compared to the corresponding intact ones. The results showed that inserting a cage increased the maximum von Mises stress and changed the load transfer in the adjacent structures. Varying the cage material or the loading conditions had a much smaller influence than varying the cancellous bone density. The denser the cancellous bone, the more the stress was concentrated underneath the cage, while the remaining regions were unloaded. This study showed that the density of the underlying cancellous bone is a more important factor for the biomechanical behaviour of a motion segment stabilized with a cage, and its eventual clinical success, than the cage material or the applied load. Inserting an intervertebral cage markedly changed the load transfer. The altered stress distribution may trigger bone remodelling and explain damage of the underlying vertebrae.     

Fehlschläge der dorsalen Spongiosaplastik der vorderen Säule

The result of spine fractures is not only bony destruction but also in most cases biomechanical instability of the motion segment. The goal of operative treatment is stability. Besides internal fixation a recommended procedure was the transpedicular transplantation of cancellous bone to achieve bony fusion in the anterior column of the spine. In a clinical study after the stabilizing operation, we found a loss of correction 30–60% that was independent of the fracture type, implant or operation procedure. The lack of healing of the bone graft was the reason for the correction loss. The assessment of 3D reconstructions, generated from the digitized picture data of CT scans, shows small volumes of cancellous bone grafts with poor contact to the neighboring vertebral body. The results indicate that transpedicular bone grafting cannot be recommended for the operative treatment of unstable thoracolumbar spinal fractures, since in most cases no bony fusion occurs. In our opinion combined anterior-posterior stabilizations are more often indicated.     

Tension band wiring-bone grafting for spondylolysis and spondylolisthesis. A clinical and biomechanical study

Patients with spondylolysis or spondylolisthesis with persistent symptoms often require surgical treatment. The purpose of this article is to present a new surgical technique and clinical results of 13 patients with symptomatic spondylolysis/spondylolisthesis who were treated with tension band wiring (intra- or intersegmental) and bone grafting techniques. This article also presents the results of biomechanical effects of these tension band wiring methods on canine lumbar spines with experimental spondylolytic defects. Thirteen adult patients, three with spondylolysis, and ten with spondylolytic spondylolisthesis, were treated with intrasegmental or intersegmental wiring with bone grafting technique, and the clinical results were evaluated at the mean follow-up period of 20 months. Patients with spondylolysis were treated with intrasegmental wiring (transverse processes to the spinous process of the same segment) with bone grafting at the lytic defect. Patients with spondylolytic spondylolisthesis were treated with intersegmental wiring (transverse process of the segment with defect to the spinous process of the same segment and to the spinous process of the segment below) with bone grafting to the defect and one-level fusion. All 13 patients had a solid spinal fusion and/or healing of the defect at the follow-up evaluation. Eleven had excellent clinical results; one a good, and one a fair result. The results of the biomechanical study showed that the experimental spondylolytic defect produced a significant decrease in bending stiffness (flexion-extension), and the wiring techniques (both the intra- and intersegment) increased the bending stiffness to that of the normal intact spinal segment.     

Posterior lumbar interbody fusion (PLIF) with cages and local bone graft in the treatment of spinal stenosis

Posterior lumbar interbody fusion (PLIF) implants are increasingly being used for 360 degrees fusion after decompression of lumbar spinal stenosis combined with degenerative instability. Both titanium and PEEK (PolyEtherEtherKetone) implants are commonly used. Assessing the clinical and radiological results as well as typical complications, such as migration of the cages, is important. In addition, questions such as which radiological parameters can be used to assess successful fusion, and whether the exclusive use of local bone graft is sufficient, are frequently debated. We prospectively evaluated 30 patients after PLIF instrumentation for degenerative lumbar spinal canal stenosis, over a course of 42 months. In all cases, titanium cages and local bone graft were used for spondylodesis. The follow-up protocol of these 30 cases included standardised clinical and radiological evaluation at 3, 6, 12 and 42 months after surgery. Overall satisfactory results were achieved. With one exception, a stable result was achieved with restoration of the intervertebral space in the anterior column. After 42 months of follow-up in most cases, a radiologically visible loss of disc space height can be demonstrated. Clinically relevant migration of the cage in the dorsal direction was detected in one case. Based on our experience, posterior lumbar interbody fusion (PLIF) can be recommended for the treatment of monosegmental and bisegmental spinal stenosis, with or without segmental instability. Postoperative evaluation is mainly based on clinical parameters since the titanium implant affects the diagnostic value of imaging studies and is responsible for artefacts. The results observed in our group of patients suggest that local autologous bone graft procured from the posterior elements after decompression is an adequate material for bone grafting in this procedure.     

Evaluation of bovine-derived bone protein with a natural coral carrier as a bone-graft substitute in a canine segmental defect model

The efficacy of a bone-graft substitute (bovine-derived bone protein in a carrier of natural coral) in the healing of a segmental defect of a weight-bearing long bone was evaluated. Twenty dogs, divided into two groups, underwent bilateral radial osteotomies with creation of a 2.5 cm defect. On one side of each dog, the defect was filled with autogenous cancellous bone graft. Contralateral defects received, in a blinded randomized fashion, cylindrical implants consisting of natural coral (calcium carbonate) or calcium carbonate enhanced with a standard dose of bovine-derived bone protein (3.0 mg/implant; 0.68 mg bone protein/cm³). The limbs were stabilized with external fixators, and all animals underwent monthly radiographs. They were killed at 12 (group 1) or 24 (group 2) weeks, and regenerated bone was Studied by biomechanical testing and histology. Radiographic union developed in all 20 radii with autogenous cancellous bone grafts and in all 10 of the radii with the composite implants. None of the radii with implants of calcium carbonate alone showed radiographic evidence of union. This represented a statistically significant difference between implant types. In addition, calcium carbonate implants both with and without bone protein demonstrated radiographic evidence of near total resorption of the radiodense carrier by 12 weeks. This resorption facilitated radiographic evaluation of healing. Mean values for. biomechanical parameters of radii with the composite implants exceeded those for the contralateral controls at 12 and 24 weeks; the difference was statistically significant at 12 weeks. Histology revealed scant residual calcium carbonate carrier at either time in the defects with calcium carbonate implants; however, a moderate amount was present in defects with the composite implants. In these specimens, the residual carrier was completely surrounded by newly formed bone that may have insulated the calcium carbonate from further degradation. The present study used a carrier of granular calcium carbonate reconstituted with bovine type-I collagen to deliver an osteoinductive protein to the defect site. This carrier is of nonhuman origin (eliminating the risk of disease transmission or antigenicity) and resorbs rapidly. In this model, bovine-derived bone protein in a natural coral carrier performed consistently better than the gold standard autogenous cancellous bone graft in terms of the amount of bone formation and strength of the healed defect. This may have implications for removal of hardware or resumption of weight-bearing in certain clinical situations. These data also indicate that coralline calcium carbonate alone. represents a poor option as a bone-graft substitute in this critical-sized segmental defect model.     

终板法伤椎植钉单节段内固定治疗不完全胸腰椎骨折的生物力学研究及临床应用

目的 对终板法伤椎植钉单节段内固定治疗胸腰椎单椎体骨折的生物力学及临床效果进行评价.方法 取猪的24个新鲜胸腰椎椎体标本,48个椎弓根,随机分成4组,分别应用"平行法"及3种不同"终板法"植钉,比较4种植钉法的抗拔出强度.同时回顾分析2003年3月至2006年6月应用该技术治疗的49例胸腰椎骨折患者手术前后伤椎的前后缘高度、后凸Cobb角、椎管内径及矫正丢失、顽固性腰痛、腰椎活动受限等并发症发生情况.结果 "终板法"椎弓根螺钉抗拔出强度明显高于"平行法","伤椎植钉"与正常椎体的"终板法"植钉具有相同的抗拔出强度.49例患者术后均得到良好复位及骨性融合,无内固定失败,无明显矫正角度丢失以及顽固性腰痛、腰椎活动受限等并发症.结论 终板法伤椎植钉单节段内固定能提供足够的抗拔出强度,临床疗效满意.     

Enhanced healing of goat femur‐defect using BMP7 gene‐modified BMSCs and load‐bearing tissue‐engineered bone

Segmental defect regeneration is still a clinical challenge. In this study, we investigated the feasibility of bone marrow stromal cells (BMSCs) infected with adenoviral vector containing the bone morphogenetic protein 7 gene (AdBMP7) and load‐bearing to enhance bone regeneration in a critically sized femoral defect in the goat model. The defects were implanted with AdBMP7‐infected BMSCs/coral (BMP7 group) or noninfected BMSCs/coral (control group), respectively, stabilized with an internal fixation rod and interlocking nails. Bridging of the segmental defects was evaluated by radiographs monthly, and confirmed by biomechanical tests. Much callus was found in the BMP7 group, and nails were taken off after 3 months of implantation, indicating that regenerated bone in the defect can be remodeled by load‐bearing, whereas after 6 months in control group. After load‐bearing, it is about 5 months; the mechanical property of newly formed bone in the BMP7 group was restored, but 8 months in control group. Our data suggested that the BMP7 gene‐modified BMSCs and load‐bearing can promote bone regeneration in segmental defects. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:412–418, 2010     

自体骨髓基质干细胞复合珊瑚修复犬下颌骨节段缺损的初步研究

目的应用自体骨髓基质干细胞(bonemarrowstromalcells,BMSCs)复合珊瑚构建组织工程化骨,修复犬下颌骨节段性缺损。方法体外扩增培养、成骨诱导犬BMSCs。将第二代细胞复合珊瑚后修复犬自体右侧3cm的下颌骨节段缺损(n=6);以单纯珊瑚植入缺损处为对照(n=6),术后12、32周分别通过影像学,大体形态观察,组织学和生物力学的方法检测骨缺损的修复效果。结果成骨诱导的BMSCs在珊瑚支架上生长良好。X线片显示12周时实验组骨痂较多,对照组材料明显吸收;32周时CT、X线片和大体观察显示术后实验组骨愈合良好,对照组为骨不连;骨密度检测示实验组显著高于对照组(P<0.05);组织学示实验组有较多成熟骨呈骨性愈合,对照组为纤维性愈合;生物力学测试实验组与正常下颌骨力学强度差异无统计学意义(P>0.05)。结论自体成骨诱导BMSCs复合珊瑚形成的组织工程化骨可修复犬下颌骨节段缺损。     

Traumatic injuries to the craniovertebral junction: a review of rare events

The craniovertebral junction is a specific region of the spine with unique anatomical and biomechanical properties that yields a wide variety of injury patterns. Junctional traumatic fractures and/or dislocations are widely reported in clinical practice, but we could identify only a subgroup of upper cervical spine traumatic injuries with very few cases reported in the literature, and for this reason may be considered rare. In some of these cases, the absence of spinal biomechanical instability, in association with moderate clinical symptoms (neck stiffness and pain) and the difficulty in fracture identification through standard cervical radiographs, leads to a high percentage of missed injuries. In other cases, traumatic events have been commonly described only in autopsy series due to the high degree of spinal biomechanical instability. Herein, we have summarized all the relevant literature concerning this issue and also included our cases, with the aim of emphasizing prompt diagnosis and correct management. We provide a guide for correctly identifying “rare” craniovertebral junction traumatic injuries.     

Radiolucent cage for cervical vertebral reconstruction: A prospective study of 17 cases with 2-year minimum follow-up

In cervical spondylotic myelopathy, extended anterior spinal cord decompression necessitates subsequent stable vertebral reconstruction. Reconstruction with an iliac crest graft and screw-plate fixation gives satisfactory clinical and radiological results, but they are often compromised by morbidity involving the bone harvest. The purpose of this study was to evaluate the contribution to cervical reconstruction of a biocompatible, radiolucent cage combined with screw-plate fixation, making use of bone harvested in situ. This prospective study was performed between July 2000 and March 2001 in eight women and nine men (mean age, 55 years) operated for cervical spondylotic myelopathy. Situated between levels C3 and C6, the cage was inserted after one corporectomy in ten patients, two corporectomies in five patients, and three corporectomies in two patients. The cage consisted of a polyester mesh impregnated with poly-L-lactic acid (PLLA) conferring temporary rigidity to the cage during bony fusion. Clinical and radiological follow-up (plain films, computed tomographic reconstruction in three cases) was performed at 2 months, 6 months, 12 months, 24 months and 36 months, postoperatively, with a mean follow-up of 30 months. Functional results were evaluated according to the Japanese Orthopaedic Associations scoring system. An independent surgeon assessed the radiological evidence of anterior cervical fusion using the grades proposed by Bridwell [6]. Every patient experienced neurological recovery. At last follow-up, radiological findings were consistent with grade I (complete fusion) in five cases, grade II (probable fusion) in ten cases, grade III (radiolucent halo in favor of non fusion) in one case, and grade IV (graft lysis) in one case with persistent neck pain. In three cases there was screw breakage (two grade II, one grade IV). None of these cases required surgical revision at latest follow-up. In extensive spinal cord decompression through an anterior approach, cervical reconstruction using the present type of cage can achieve clinical results comparable to conventional techniques. The rigidity of the cage meets biomechanical imperatives. Its radiolucency permits one to monitor the course of consolidation, contrary to metal cages. The cases of probable non-fusion and screw breakage were not accompanied by signs of instability on the flexion extension films. This cage meets the biologic and biomechanical imperatives of cervical reconstruction. It obviates complications involving bone harvest.     

An experimental approach to spinal fusion using sintered bovine bone in a pig model

Sintered bovine bone is a biomaterial based on calcium phosphate, an organized crystal of bone mineral that possesses a natural trabecular structure. The authors considered whether sintered bovine bone can integrate with recipient bone and adjust to the strength of recipient bone for anterior spinal fusion in an animal model. Either autologous iliac bone or sintered bovine bone was implanted for a spinal body fusion. Some pigs underwent exposure of the spinal bodies without implantation. Based on radiographic evaluation, manual palpation, biomechanical testing, and histologic examination, spinal fusion with sintered bovine bone resulted in a composition and structure similar to that of the autograft (or of no implantation). The sintered bovine bone with its moderate strength tended to adjust to the bone stiffness of the host bone in the specimens as new bone grew.     

自体脂肪干细胞复合珊瑚修复犬颅骨标准缺损的初步研究

目的 应用自体脂肪干细胞(adipose-derived stem cells,ADSCs)复合珊瑚构建组织工程化骨,修复犬颅骨标准缺损.方法 体外扩增培养、成骨诱导Beagle犬ADSCs,将第2代细胞接种在珊瑚支架上共同培养.制造实验犬双侧颅骨全层标准缺损(20 mm×20 mm),一侧以细胞材料复合物修复作为实验组(n=7),另一侧以单纯珊瑚材料修复作为对照组(n=7).术后24周分别通过影像学、大体形态观察、生物力学检测、组织学方法检测颅骨缺损的修复效果.结果 成骨诱导的犬ADSCs体外呈现成骨特性,在珊瑚支架上生长良好.3D-CT重建显示术后12周实验组有新生骨痂形成,对照组材料大部分降解;24周时实验组为骨性愈合,对照组为骨不连.24周时实验组缺损修复百分比为(84.19±6.45)%,显著高于对照组的(25.04 ±18.82)%(P<0.01).大体观察见实验组由新生骨痂修复缺损,对照组缺损边缘可见少量骨痂形成,主要为软组织充填;24周生物力学检测修复组织能耐受的最大压力载荷,实验组为(73.45±17.26)N,为犬顶骨最大压力负荷(104.27±22.71)N的70%,两者比较差异有统计学意义(P<0.01),对照组为软组织无法完成上述检测.HE染色见实验组有较多成熟骨呈骨性愈合,对照组为纤维性愈合.结论 自体成骨诱导的ADSCs复合珊瑚形成的组织工程化骨可修复犬颅骨标准缺损.