New cell-based technologies in bone and cartilage tissue engineering. I. Bone reconstruction

A tissue engineering, cell-based therapeutic approach could be essential for extensive bone or cartilage reconstruction. This article is divided in two chapters and describes new cell-based surgical techniques for cartilage and bone reconstruction. In the first part on bone reconstruction, marrow-derived osteogenic progenitor cells combined with hydroxyapatite were utilized. The validity of this model has been shown for the repair of critical size bone defects in large size animal models. We used this cell-based therapeutic approach to treat 3 patients with large bone defects, achieving bone reconstruction.     

Implantation of orthobiologic, biodegradable scaffolds in osteochondral repair

The treatment of articular cartilage lesions is complicated, but novel tissue engineering approaches seem to improve the outcome. A tissue engineering approach is less invasive and reduces surgical time, periosteal hypertrophy, and morbidity. Cell-based therapies using scaffolds have advantages compared with microfracture techniques, but the efficacy and cost-effectiveness need to be investigated. Second-generation cell-based therapies have lower morbidity and the ease of the technique is not significantly different from that of first-generation autologous chondrocyte implantation techniques. Third-generation cell-based therapies such as the use of tissue engineered scaffolds need to be studied in more detail.     

Value of autologous transplantation of osteo-chondral paste in reconstruction of experimental cartilage defects. Part II. Microscopic analysis of integration with surrounding cartilage, structural integrity and subchondral bone reconstruction in repair tissue]

INTRODUCTION: A limited ability of the cartilage to heal after trauma was the reason to start research on new methods concerning better cartilage reconstruction. The aim of the study was evaluation of repair tissue integration with surrounding cartilage, its structural integrity and subchondral bone reconstruction after osteo-chondral paste transplantation. MATERIAL AND METHODS: Full thickness defect (IV degree--ICRS scale) on distal rabbit femur joint surface was made. Three groups were specified: A--defect with paste graft (cartilage and contiguous bone collected from joint surface, crushed into homogenous paste; B--defect with the paste graft covered with periosteum; C--defect left unfilled. The follow-up periods were established at 4, 8, 12 weeks. Repair tissue was evaluated microscopically according to modified O'Driscoll scale. RESULTS: Newly formed tissue was well integrated with surrounding cartilage in group A (paste graft). That trade of repair tissue in group A was much better than in other groups, especially in late observations. Structural integrity of tissue filling the defect was similar to integrity of normal cartilage in groups A and C, but tissue formed in group C didn't represent a hyaline-like cartilage character. In all the examined groups reconstruction of subchondral bone exhibited similar rate. 12 weeks from the procedure, around 80% of subchondral bone was rebuilt. The obtained results indicate, that osteo-chondral paste autologous transplantation in cartilage defects treatment effects with forming well integrated (structurally and with surrounding cartilage) cartilage tissue, of almost complete subchondral bone rebuilding.     

Autologous Transplantation of Press‐fit Bone Cylinders in the Treatment of Pelvic Nonunion

The present study describes method for autologous bone transplantation to an area of nonunion at the pelvic ring in a way that ensures the best possible bone‐to‐bone interface (“press‐fit”) and provides optimal preconditions for the ingrowth of the bone graft. We modified a technique that has been used to transplant press‐fit bone‐baseplate‐cartilage cylinders for the repair of joint cartilage defects. The technique allows for precise harvesting of bone cylinders with a diamond‐coated and fluid‐cooled instrument. At the site where the graft shall be inserted, a cylindrical hole is created with a corresponding hollow diamond‐coated trephine. This ensures an optimal press‐fit implantation of the graft. The new surgical technique has been applied in four patients with nonunion of the pelvic ring. No intraoperative or postoperative complications occurred. In three patients, the procedure led to a reduction of pain and a higher level of mobility as well as a timely radiographic union (imaging not available for another patient). Our technique offers a valuable new treatment option for pelvic nonunion. The current article serves as a proof of concept. Future comparative studies will have to determine its value in detail.     

Value of osteo-chondral paste autologous transplantation in experimental cartilage defects reconstruction. Part III--Microscopic analysis of reconstructed cartilage thickness and surface regularity]

INTRODUCTION: A limited ability of the cartilage to heal after trauma was the reason to start research on new methods concerning better cartilage reconstruction. The aim of the study was evaluation of repair tissue thickness and surface regularity after osteochondral paste transplantation. MATERIAL AND METHODS: Full thickness defect (IV(o)--ICRS scale) on distal rabbit femur joint surface was made. Three groups were specified: A--defect with paste graft (cartilage and contiguous bone collected from joint surface, crushed into homogenous paste; B--defect with the paste graft covered with periosteum; C--defect left unfilled. The follow-up periods were established at 4, 8, 12 weeks. Repair tissue was evaluated microscopically according to modified O'Driscoll scale. RESULTS: Newly formed tissue was well integrated with surrounding cartilage in group A (paste graft). That trait of repair tissue in group A was much better than in other groups, especially in late observations. Structural integrity of tissue filling the defect was similar to integrity of normal cartilage in groups A and C, but tissue formed in group C didn't represent a hyaline-like cartilage character. In all the examined groups reconstruction of subchondral bone exhibited similar rate. 12 weeks from the procedure, around 80% of subchondral bone was rebuilt. The obtained results indicate, that osteochondral paste autologous transplantation in cartilage defects treatment effects with forming well integrated (structurally and with surrounding cartilage) cartilage tissue, of almost complete subchondral bone rebuilding.     

Tissue Engineering mit mesenchymalen Stammzellen zur Knorpel- und Knochenneubildung

Tissue engineering offers the possibility to fabricate living substitutes for tissues and organs by combining histogenic cells and biocompatible carrier materials. Pluripotent mesenchymal stem cells are isolated and subcultured ex vivo and then their histogenic differentiation is induced by external factors. The fabrication of bone and cartilage constructs, their combinations and gene therapeutic approaches are demonstrated. Advantages and disadvantages of these methods are described by in vitro and in vitro testing. The proof of histotypical function after implantation in vivo is essential. The use of autologous cells and tissue engineering methods offers the possibility to overcome the disadvantages of classical tissue reconstruction--donor site morbidity of autologous grafts, immunogenicity of allogenic grafts and loosening of alloplastic implants. Furthermore, tissue engineering widens the spectrum of surgical indications in bone and cartilage reconstruction.     

耳再造术中自体肋软骨切取的手术要点及相关问题分析

目的 探讨耳再造术中自体肋软骨切取手术的设计原则及操作要点.方法 回顾总结自2013年3月至2014年2月,403例耳再造术中自体肋软骨切取手术的设计方案及操作过程,强调对目标肋软骨的触诊,以确定手术切口位置;合理设计切口位置,采用合适的手术器械使切口最小化;根据整体手术流程,决定肋软骨切取次序,避免成为影响手术进度的瓶颈环节;防止切口周缘的过度损伤,对创缘进行适当处理后,采用美容缝合技术关闭伤口.结果 最小化手术切口的同时,采用美容缝合技术处理伤口,所有患者均恢复良好,切口Ⅰ期愈合,患者对胸部小切口满意.合理的切取顺序加快了整体手术进度,从而缩短了手术时间.结论 结合手术需求,准确定位目标肋软骨位置,合理设计并采用合适的手术器械,是手术切口最小化的重要条件;合理的切取次序能够优化手术流程,有助于缩短手术时间.     

Minced cartilage without cell culture serves as an effective intraoperative cell source for cartilage repair.

Traumatic articular cartilage injuries heal poorly and may predispose patients to the early onset of osteoarthritis. One current treatment relies on surgical delivery of autologous chondrocytes that are prepared, prior to implantation, through ex vivo cell expansion of cartilage biopsy cells. The requirement for cell expansion, however, is both complex and expensive and has proven to be a major hurdle in achieving a widespread adoption of the treatment. This study presents evidence that autologous chondrocyte implantation can be delivered without requiring ex vivo cell expansion. The proposed improvement relies on mechanical fragmentation of cartilage tissue sufficient to mobilize embedded chondrocytes via increased tissue surface area. Our outgrowth study, which was used to demonstrate chondrocyte migration and growth, indicated that fragmented cartilage tissue is a rich source for chondrocyte redistribution. The chondrocytes outgrown into 3-D scaffolds also formed cartilage-like tissue when implanted in SCID mice. Direct treatment of full-thickness chondral defects in goats using cartilage fragments on a resorbable scaffold produced hyaline-like repair tissue at 6 months. Thus, delivery of chondrocytes in the form of cartilage tissue fragments in conjunction with appropriate polymeric scaffolds provides a novel intraoperative approach for cell-based cartilage repair.     

Stem Cell Therapy in Cartilage Repair—Culture-Free and Cell Culture–Based Methods

In order to overcome potential problems associated with autologous chondrocyte implantation, mesenchymal stem cell-based therapies could be potential alternatives. Conventional stem cell-based therapy accompanies the separation of cells from tissue followed by monolayer culture for the expansion of cell numbers. On the other hand, the cost of cell culture under quality control is high, which could be a potential barrier for industrialization. In order to reduce the cost associated cell culture, culture-free cell-based therapies have been investigated with the use of bone marrow aspirate. In this chapter, we will introduce the three stem cell-based therapies in cartilage repair. The first two procedures are using cell culture methods and the last one with cell-free method. All the three methods have been into the stage of clinical trials and their surgical procedures as well as their preliminary results will be reported.     

Osteoregenerative lateral suboccipital craniectomy using fibrin glue

Summary This report describes a simple technique of cranioplasty for suboccipital craniectomy and the results of a clinical study to assess the effects of fibrin glue on regeneration of the skull. Cranioplasty using a mixture of autologous bone chips and human allogenic fibrin glue was performed in 31 patients who received lateral suboccipital craniectomy. Long-term observations with three-dimensional CT showed satisfactory reconstruction of the mastoid-occipital bone plate in 25 patients (81%); among them, a nearly complete reconstruction of the occipital bone (plate) was found in 14 patients. Regeneration of the bone began 6 months after surgery on the inner surface, adjacent to the dura mater. In conclusion, the present technique provides a new simple method to restore an autologous bone plate in a cranial defect made by piecemeal craniectomy.     

耳再造术的体会——附106例全耳再造病例

目的 回顾总结耳再造的经历和经验,力求寻找较理想的耳再造术方法.方法 以自体肋软骨雕塑耳支架,分期耳再造术.结果 86例未行皮肤扩张,按分期耳再造术法,除有2例部分皮肤血运障碍,再另行处理,1例术后感染,其余83例外形良好,轮廓清晰.20例行皮肤扩张后耳再造术,19例外形较满意,轮廓较清晰.结论 耳再造术是一个精细的手术,影响因素较多,足够的皮肤覆盖,精致的耳支架,细小结构的成形,以及术后的处理,都会影响手术的最终效果.以肋软骨作支架,分期耳再造术是较可靠的治疗的方法.扩张皮肤后耳再造术提供了充足的皮肤,是一个较理想的手术方法.     

Autologe Rekonstruktion schwerer Fehlbildungen und Defekte der Ohrmuschel

The construction of an auricle using autologous material is undoubtedly one of the most demanding tasks in facial plastic surgery. Considered practically impossible only a few decades ago, today we are able to achieve reproducible, natural-looking and long-term stable surgical results. The cornerstone of ear reconstruction is the use of costal cartilage to reconstruct or replace the ear’s deficient cartilage structure. The subtle dissection and reconstruction of the ear’s skin and soft tissue is also of great importance. This aspect is multifaceted and subsumes all plastic surgical techniques including free flaps. In this paper, we wish to provide an overview of our strategies for the correction of microtia and the reconstruction of severe external ear deformities.     

膝关节软骨损伤的外科治疗进展

关节软骨损伤后,软骨缺损通常缺乏自行修复能力,要求外科修复。传统外科治疗软骨损伤包括关节镜下冲洗清理术、微骨折术、自体骨软骨移植术、异体骨软骨移植术和自体软骨细胞移植等方法。关节冲洗清理术去除了关节内致痛因素,操作简单,应用广泛,早期疗效确切。微骨折术及自体骨软骨移植对小面积的软骨缺损修复较为理想,然而远期临床观察发现钻孔渗透修复的纤维软骨会降低微骨折术后疗效,相对于重建负重区关节面完整性自体骨软骨移植更具有优势。自体软骨细胞移植及异体骨软骨移植适用于更大面积的软骨缺损,异体骨软骨移植术后存活率受到局部排斥反应影响,从而降低了远期疗效。软骨组织工程技术可最大限度地提高自体软骨细胞移植的修复质量,实现修复组织接近透明软骨,但对于累及软骨下骨板、反应性骨水肿、严重骨量丢失或下肢轴线不良具有局限性。近年来许多新技术陆续应用于软骨损伤治疗领域,创伤小、操作简便、恢复快、疗效好、花费低、多技术联合应用的外科修复技术将会成为未来的治疗软骨损伤的重要手段。目前如何提高软骨修复质量,更具抗压、耐磨性,仍亟待解决。     

Orderly osteochondral regeneration in a sheep model using a novel nano‐composite multilayered biomaterial

The objective of this article was to investigate the safety and regenerative potential of a newly developed biomimetic scaffold when applied to osteochondral defects in an animal model. A new multilayer gradient nano‐composite scaffold was obtained by nucleating collagen fibrils with hydroxyapatite nanoparticles. In the femoral condyles of 12 sheep, 24 osteochondral lesions were created. Animals were randomized into three treatment groups: scaffold alone, scaffold colonized in vitro with autologous chondrocytes and empty defects. Six months after surgery, the animals were sacrificed and the lesions were histologically evaluated. Histologic and gross evaluation of specimens showed good integration of the chondral surface in all groups except for the control group. Significantly better bone regeneration was observed both in the group receiving the scaffold alone and in the group with scaffold loaded with autologous chondrocytes. No difference in cartilage surface reconstruction and osteochondral defect filling was noted between cell‐seeded and cell‐free groups. In the control group, no bone or cartilage defect healing occurred, and the defects were filled with fibrous tissue. Quantitative macroscopic and histological score evaluations confirmed the qualitative trends observed. The results of the present study showed that this novel osteochondral scaffold is safe and easy to use, and may represent a suitable matrix to direct and coordinate the process of bone and hyaline‐like cartilage regeneration. The comparable regeneration process observed with or without autologous chondrocytes suggests that the main mode of action of the scaffold is based on the recruitment of local cells. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:116–124, 2010     

A cranial reconstruction using an autologous split calvarial bone combined with a free graft of temporal loose areolar tissue

We report a new simple method of cranial reconstruction using an autologous split calvarial bone, combined with free graft of temporal loose areolar tissue. A 58-year-old woman suffered from a cranium defect on her left side. The originating bone infection happened after initial brain tumor surgery. Part of the left side of her scalp just above the damaged cranial area had become very thin due to previous cranioplasty, which involved a titanium mesh plate and postoperative infections. We performed a cranial reconstruction with an autologous split calvarial bone, combined with loose areolar tissue free graft, for the damaged area with skin from the inner side. In our case, we expect that the addition of the free graft of loose areolar tissue to the autologous calvarial bone graft will effectively contribute to the skin's healing and provide good cosmetic results in our short follow-up period. A free graft of loose areolar tissue for the damaged skin area may be a new optional method for cranial reconstruction in a patient with skin trouble.     

Cranioplasty for repair of a large bone defect with autologous and homologous bone in children

Cranioplasty is a well-established reconstructive procedure for restoring craniocerebral protection and improving cosmetic defects. Most allograft materials are not suitable in pediatric patients owing to skull growth; thus, autologous bone is often preferred in the reconstruction of the pediatric skull because of its capacity to osseointegrate and grow with the pediatric skeleton.A 33-month-old boy with Ewing sarcoma of the right frontal bone underwent surgical treatment with tumor excision. The resected bone was reconstructed with full-thickness calvaria harvested from the right parietal region. The residual parietal gap was filled with homologous bone taken from the iliac wing.This reconstructive technique was chosen to guarantee normal development of the frontal region and tissue integration, while considering possible radiotherapy after the primary surgery.     

Tissue Engineering for Plastic Surgeons: A Primer

A central tenet of reconstructive surgery is the principle of “replacing like with like.” However, due to limitations in the availability of autologous tissue or because of the complications that may ensue from harvesting it, autologous reconstruction may be impractical to perform or too costly in terms of patient donor-site morbidity. The field of tissue engineering has long held promise to alleviate these shortcomings. Scaffolds are the structural building blocks of tissue-engineered constructs, akin to the extracellular matrix within native tissues. Commonly used scaffolds include allogenic or xenogenic decellularized tissue, synthetic or naturally derived hydrogels, and synthetic biodegradable nonhydrogel polymeric scaffolds. Embryonic, induced pluripotent, and mesenchymal stem cells also hold immense potential for regenerative purposes. Chemical signals including growth factors and cytokines may be harnessed to augment wound healing and tissue regeneration. Tissue engineering is already clinically prevalent in the fields of breast augmentation and reconstruction, skin substitutes, wound healing, auricular reconstruction, and bone, cartilage, and nerve grafting. Future directions for tissue engineering in plastic surgery include the development of prevascularized constructs and rationally designed scaffolds, the use of stem cells to regenerate organs and tissues, and gene therapy.     

应用自体鼻中隔软骨与自体真皮组织修复假体隆鼻术后远期并发症的临床研究

目的探讨应用自体组织综合性修复假体隆鼻并发症的方法和疗效。方法针对36例固体硅胶假体隆鼻术后鼻背、鼻尖发红及鼻尖假体显露、穿出的患者,采取经鼻小柱开放性切口取出假体,剥除包膜,应用患者自体鼻中隔软骨及臀部真皮组织进行综合鼻整形修复。自体鼻中隔软骨应用于鼻小柱支撑及鼻尖覆盖物,白体真皮组织去表皮及脂肪后,修剪成合适形态,置于鼻背及鼻尖处,修复变薄的皮肤组织,塑造合适的形态。结果本组共36例患者,术后均I期愈合;术后未出现感染、软骨外露及移位等情况,疗效满意。结论自体鼻中隔软骨联合真皮组织移植,可有效修复假体隆鼻引起的并发症,术后外观形态好,值得临床推广。     

氩氦刀冷冻消融联合手术治疗骨与软组织肿瘤

目的分析氩氦刀冷冻消融联合手术治疗骨与软组织肿瘤的安全性及有效性。方法采用以色列伽利略氩氦刀联合手术治疗29例骨与软组织肿瘤患者。结果患者均获得随访,时间6~55个月。27例关节功能良好,活动度正常;2例内固定及外固定支具按期拆除。随访期内2例原位复发,1例术后早期皮缘水肿。29例均无肌肉组织、神经血管损伤、病理性骨折等并发症,引流量无增加。影像学随访结果:27例骨重建良好,关节软骨无早期退变,关节间隙正常或接近正常;28例自体关节骨结构保留,1例骨断端延期愈合。结论氩氦刀冷冻消融联合手术治疗骨与软组织肿瘤安全有效。     

Structural characteristics of repair tissue of cricoid cartilage defects treated with recombinant human bone morphogenetic protein-2

We examined the structural characteristics of repair tissue induced by recombinant human bone morphogenetic protein-2 in a rabbit model of laryngotracheal reconstruction. Twenty-four New Zealand White rabbits were randomly divided into four groups of six rabbits. Two groups were treated with recombinant human bone morphogenetic protein-2 delivered on an absorbable collagen sponge, while two groups were used as controls. Rabbits were euthanized at 1 and 4 weeks after surgery. The larynx was removed, fixed, and sectioned. The sections were stained with hematoxylin-eosin, safranine O/fast green, and immunostained with an antibody for tissue inhibitor of metalloproteinases-1. In rabbits treated with bone morphogenetic protein-2, the defects were filled with new cartilage and bone at 4 weeks after surgery. There were no discontinuities or gaps at the margins of the cartilage defects. Proteoglycans were synthesized in new cartilage in rabbits treated with bone morphogenetic protein-2, and were present 4 weeks after surgery. The general aspects of the vascular pattern and the pattern of tissue inhibitor of metalloproteinases-1 expression were similar in control and treated rabbits, both 1 week and 4 weeks after surgery. The repair tissue induced by recombinant human bone morphogenetic protein-2 consisted of new cartilage and bone perfectly integrated with host tissue at the site of the cricoid cartilage defects. This new cartilage was able to mature and produce proteoglycans.