Autologous chondrocyte implantation at the knee using a bilayer collagen membrane with bone graft. A preliminary report

Autologous chondrocyte implantation (ACI) is a technique used for the treatment of symptomatic osteochondral defects of the knee. A variation of the original periosteum membrane technique is the matrix-induced autologous chondrocyte implantation (MACI) technique. The MACI membrane consists of a porcine type-I/III collagen bilayer seeded with chondrocytes. Osteochondral defects deeper than 8 to 10 mm usually require bone grafting either before or at the time of transplantation of cartilage. We have used a variation of Peterson's ACI-periosteum sandwich technique using two MACI membranes with bone graft which avoids periosteal harvesting. The procedure is suture-free and requires less operating time and surgical exposure. We performed this MACI-sandwich technique on eight patients, five of whom were assessed at six months and one year post-operatively using the modified Cincinnati knee, the Stanmore functional rating and the visual analogue pain scores. All patients improved within six months with further improvement at one year. The clinical outcome was good or excellent in four after six months and one year. No significant graft-associated complications were observed. Our early results of the MACI-sandwich technique are encouraging although larger medium-term studies are required before there is widespread adoption of the technique.     

Arthroscopic autologous chondrocyte implantation for the treatment of a chondral defect in the tibial plateau of the knee

The matrix-induced autologous chondrocyte implantation (MACI; Verigen, Leverküsen, Germany) is a tissue engineering technique for the treatment of deep chondral lesions. Cultured chondrocytes are seeded on a collagen membrane that can be implanted into the defect using exclusively fibrin glue. These features imply some surgical advantages with respect to the traditional ACI technique, such as the possibility of performing the procedure in articular sites, in which putting stitches for the periosteal patch is impossible. We report on the arthroscopic MACI technique for the treatment of a chondral defect of the knee. A 25-year-old man suffered persistent pain at the left knee after a violent direct trauma. Magnetic resonance imaging (MRI) and arthroscopic examination at the time of cartilage biopsy revealed a 2-cm² chondral lesion in the posterior portion of the lateral tibial plateau. The implantation procedure was performed through traditional arthroscopic portals, and the seeded membrane was fixed with fibrin glue, excluding water flow temporarily. Implant stability was verified intraoperatively, and filling of the defect was shown 12 months after surgery by MRI, which showed a hyaline-like cartilage signal. In this specific case, the arthroscopic approach allowed to achieve an optimal view of the lesion, without sacrificing any tendinous or ligamentous structure of the knee.     

Biomaterialien für die autologe Knorpelzelltransplantation

Autologous chondrocyte transplantation (ACT) is a cell-based biological cartilage repair procedure for the regeneration of injured articular cartilage. The further modification of classical ACT to matrix-associated autologous chondrocyte transplantation (MACT) includes the use of biomaterials as cell carriers and has biological and surgical advantages. The use of biomaterials as cell carriers for chondrocytes requires the analysis of cell culture conditions, cell-cell and cell-matrix interactions and also the determination of chondrocytic differentiation. The biomaterials used preserve the specific cellular architecture of chondrocytes and the combination of cultivated cells with biomaterials leads to the formation of cartilage-specific extracellular matrix components.     

Autologous chondrocyte implantation versus matrix-induced autologous chondrocyte implantation for osteochondral defects of the knee: a prospective, randomised study

Autologous chondrocyte implantation (ACI) is used widely as a treatment for symptomatic chondral and osteochondral defects of the knee. Variations of the original periosteum-cover technique include the use of porcine-derived type I/type III collagen as a cover (ACI-C) and matrix-induced autologous chondrocyte implantation (MACI) using a collagen bilayer seeded with chondrocytes. We have performed a prospective, randomised comparison of ACI-C and MACI for the treatment of symptomatic chondral defects of the knee in 91 patients, of whom 44 received ACI-C and 47 MACI grafts. Both treatments resulted in improvement of the clinical score after one year. The mean modified Cincinnati knee score increased by 17.6 in the ACI-C group and 19.6 in the MACI group (p = 0.32). Arthroscopic assessments performed after one year showed a good to excellent International Cartilage Repair Society score in 79.2% of ACI-C and 66.6% of MACI grafts. Hyaline-like cartilage or hyaline-like cartilage with fibrocartilage was found in the biopsies of 43.9% of the ACI-C and 36.4% of the MACI grafts after one year. The rate of hypertrophy of the graft was 9% (4 of 44) in the ACI-C group and 6% (3 of 47) in the MACI group. The frequency of re-operation was 9% in each group. We conclude that the clinical, arthroscopic and histological outcomes are comparable for both ACI-C and MACI. While MACI is technically attractive, further long-term studies are required before the technique is widely adopted.     

Arthroscopic three dimensional autologous chondrocyte transplantation with navigation-guided cartilage defect size assessment

Introduction

The treatment of large full thickness cartilage defects with matrix guided autologous chondrocyte transplantation shows promising results. However, in many cases an arthrotomy is needed to implant the cell seeded scaffolds. Recently techniques have been developed for arthroscopically guided ACT implantation. Correct defect mapping, to assess size and depth of the chondral lesions, and precise scaffold preparation and fixation are crucial for successful chondrocyte transplantation and remain to be not sufficiently optimized.

Method

In the present study, the geometries of two cartilage defects in cadaver knees were three times assessed, measured and transferred to biodegradable scaffolds with a navigation system by three different executors. The scaffolds were arthroscopically implanted into the cartilage defects.

Results

The cartilage defect assessment was reproducible between all executors for all defect geometries. The implanted scaffolds showed a correct defect filling.

Conclusion

The study showed the feasibility of an arthroscopic implantation of scaffolds for autologous chondrocytes transplantation. Navigation was a useful tool to exactly assess the cartilage defect geometry and allowed a precise transfer of navigated cartilage defect geometries for individualized scaffold preparation. Navigation can help to accomplish and optimize arthroscopically guided chondrocyte transplantations.     

Chondrocyte transplantation to articular cartilage explants in vitro

The transplantation of chondrocytes has shown promise for augmenting the repair of defects in articular cartilage. This in vitro study examined the efficiency of the transplantation of bovine chondrocytes onto articular cartilage disks and the ability of the transplanted chondrocytes to subsequently synthesize and deposit proteoglycan. The radiolabeling of chondrocyte cultures with [³H]thymidine, followed by 4 days of chase incubation, resulted in the incorporation of 98% of the radiolabel into DNA (as assessed by susceptibility to DNase). At the end of the culture period, the [³H]DNA was stable, with a half-life of radioactivity loss into the medium of 73 days. With use of radiolabeled chondrocytes for quantitation, the efficiency of transplantation onto a cartilage substrate was 93 ± 4% for seeding densities of as much as 650,000 cells per cm² and a seeding duration of 1 hour. These findings were confirmed both by tracking cells stained with 5-chlormethylfluorescein diacetate and by quantitating DNA. During the 16 hours after seeding onto a cartilage substrate (in which the endogenous cells had been lysed by lyophilization), the transplanted cells synthesized sulfated proteoglycan in direct proportion to the number of cells seeded. Most (83%) of the newly synthesized proteoglycan was released into the medium rather than retained within the layer of transplanted cells and the recipient cartilage substrate. Comparative studies with lyophilized-rehydrated or live cartilage as the recipient substrate indicated a similar efficiency of chondrocyte seeding and proteoglycan synthesis by the seeded chondrocytes. The transplanted cells retained the chondrocyte phenotype, as judged by a high proportion of the [³⁵S]macromolecules being in the form of aggrecan that was capable of aggregating with hyaluronan and link protein, as well as by immunostaining within and around the transplanted cells for type-II, but not type-1, collagen. These results indicate that the number of chondrocytes transplanted onto a cut cartilage surface greatly affects the level of matrix synthesis; this in turn may affect repair.     

Bone morphogenetic protein (BMP)-2 enhances the expression of type II collagen and aggrecan in chondrocytes embedded in alginate beads

OBJECTIVE: For autologous chondrocyte transplantation (ACT) chondrocytes are expanded in vitro. During expansion these cells may dedifferentiate. This change in phenotype is characterized by a raised expression of type I collagen and a decrease in type II collagen expression. Since high expression of type II collagen is of central importance for the properties of hyaline cartilage, we investigated if the growth factor bone morphogenetic protein-2 (BMP-2) may modulate the chondrogenic phenotype in monolayer cell cultures and in three-dimensional culture systems. DESIGN: Chondrocytes from articular knee cartilage of 11 individuals (average age: 39.8 years) with no history of joint disease were isolated and seeded either in monolayer cultures or embedded in alginate beads in presence or absence of human recombinant BMP-2 (hr-BMP-2). Then, cells were harvested and analysis of the chondrogenic phenotype was performed using quantitative RT-PCR, immunocytochemistry and ELISA. RESULTS: Addition of BMP-2 to chondrocytes expanded in two-dimensional (2D) cultures during the first subculture (P1) had no effect on mRNA amounts encoding type II collagen and interleukin-1beta (IL-1beta). In contrast, seeding chondrocytes in three-dimensional (3D) alginate cultures raised type II collagen expression significantly and addition of BMP-2 enhanced this effect. CONCLUSIONS: We conclude that chondrocytes during expansion for ACT may benefit from BMP-2 activation only when seeded in an appropriate 3D culture system.     

Autologous chondrocyte implantation--technique and long-term follow-up

Cartilage has a limited capacity for self repair after injury. This biological deficiency has led to a variety of surgical attempts to improve the repair of injured articular cartilage surfaces over the past 50 years. The first example of clinical cartilage tissue engineering was performed in 1987 when a knee with an articular cartilage defect on the femoral condyle was treated by implanting the patient's own chondrocytes that had been expanded in vitro into the defect in combination with a covering mechanical membrane-the periosteum. This technology is either termed autologous chondrocyte transplantation (ACT) or autologous chondrocyte implantation (ACI). Today, many modifications of the technique exist, from the first generation to now second and third generations of chondrocyte implantation. This paper describes the basic techniques for the clinical use of chondrocyte implantation and gives an update on the clinical results.     

基质诱导的自体软骨细胞移植术修复膝关节软骨缺损1O例术后2年的随访

目的应用基质诱导的自体软骨细胞移植技术（MACI,Genzyme,America）对膝关节软骨损伤的患者进行治疗,通过对患者进行术后2年的随访分析,评价MACI治疗的安全性和有效性。方法从2004年至2008年11月,对10例患者实施MACI手术。患者平均年龄34.9岁（14～57岁）,缺损的平均面积（3.69±2.62）cm2/处（0.4～8cm2,n=20）。MACI技术是从患者非负重区取自体关节软骨,进行体外消化并分离出软骨细胞,培养扩增后接种在Ⅰ/Ⅲ型双层胶原膜上。移植前按缺损的部位修剪成相应形状,用生物蛋白胶将胶原膜粘贴在关节软骨缺损处。分别于术前1周、术后3个月、6个月、1年和2年使用KOOS评分问卷进行临床康复效果的评估并进行术后核磁共振的检测（MRI）。此外,术后对2例患者进行了3次关节镜检查和2次组织学检测。结果 10例患者术后均未发生并发症及与手术相关的不良事件。患者术后3个月KOOS评分显示疼痛明显改善（P〈0.05）;术后6个月KOOS评分显示：疼痛、症状、日常生活、运动及娱乐和生活质量5项均明显升高,5项评分间有统计学差异（P〈0.05）。术后1年和2年患者的情况得到了持续的改善（P〈0.05）。患者术后3个月的MRI显示软骨缺损部位得到大部分填充和修复;6个月移植软骨基本与周围软骨完全整合;1年后修复组织呈等信号,软骨下骨髓水肿消失;2年后大部分患者软骨修复组织信号与周围组织信号强度一致,软骨下骨无骨髓水肿。术后15个月和2年的组织学检查显示新生的软骨组织以透明软骨为主。MACI手术一般都能在2h内完成,术中出血量小于100ml。结论 MACI技术是修复关节软骨缺损安全、可靠和有效的治疗措施,具有操作简单、手术时间短和术中出血量少等特点。     

Matrixgekoppelte autologe Knorpelzelltransplantation

Modification of classic autologous cartilage transplantation (ACT) with the use of biomaterials as cell carriers as matrix-associated autologous chondrocyte transplantation (MACT) has biological and surgical advantages. Three different biomaterials were used as cell carriers in the present study: a scaffold consisting of collagen types I and III, a hyaluronan scaffold and a three-dimensional gel of collagen type I. Cartilage cell transplants were investigated by histological techniques and by electron microscopy. High resolution magnetic resonance imaging (MRI) was used for in vivo examination of transplant integration. The used biodegradable materials largely assumed the specific cellular architecture of chondrocytes, with heterochromatin-poor cell nuclei and abundant formation of cell organelles. Culturing the cells in association with the biomaterials facilitated the synthesis of cartilage-specific extracellular matrix substances with the formation of filamentous and flaky structures. MRT revealed filling of the defects and integration of the transplant into the adjacent native cartilage. The selection of an appropriate cell carrier requires analysis of the cell culture conditions and of the cell-cell and cell-matrix interactions and the determination of chondrocytic differentiation.     

Autologe Chondrozytentransplantation

Untreated focal articular cartilage defects may lead to secondary osteoarthritis. Symptomatic full-thickness defects in young patients that are located in the medial or lateral femoral condyle, trochlea, or patella and range in size from 3 cm(2) to 10 cm(2) as well as defects of the ventral talus are indications for autologous chondrocyte transplantation (ACT). Another indication for ACT are cartilage defects for which previous operative measures have failed. Osteoarthritis and kissing lesions are contraindications. Axial malalignment and knee joint instability need to be corrected. Second-generation ACT procedures are based on three-dimensional biomaterials in which the articular chondrocytes are seeded prior to implantation. Randomized trials demonstrate clinical, radiographic, and histologic findings that are similar to marrow-stimulating techniques such as microfracture. Long-term studies are needed to determine the effect of ACT on the development of osteoarthritis.     

Interaktion zwischen humanen Chondrozyten und extrazellulärer Matrix in vitro

BACKGROUND: Autologous chondrocyte transplantation (ACT) has had reasonable success for repairing small articular cartilage defects. A limiting factor for ACT is, however, the in vitro cultivation of chondrocytes because it leads to dedifferentiation. Therefore, the goal of this work was to optimize the monolayer culture of chondrocytes in vitro. MATERIAL AND METHOD: Human articular chondrocytes were plated on either collagen type II or untreated surfaces. The cells were evaluated morphologically and with immunoblotting. RESULTS: On collagen type II surfaces, a stable chondrogenic phenotype, expression of beta1-integrin, and a significant activation of phosphorylated intracellular proteins and the adaptor protein Shc could be observed up to day 20 in culture. Treatment with beta1 integrin antibody led to a loss of cell adhesion (82%). The results indicate that on collagen type II, beta1-integrin receptors are activated. Through the activation of Shc, these stimulate the Ras-MAPK pathway, which stabilizes the chondrogenic phenotype. CONCLUSION: Our results provide a practical and low-cost solution for improved long-term chondrocyte cultivation, thus providing a new perspective for using ACT on larger or arthrotic cartilage defects.     

Comparison of two different matrix-based autologous chondrocyte transplantation systems: 1 year follow-up results

Purpose  

The treatment of full-thickness cartilage defects of the knee is a common problem in orthopaedic surgery. Autologous chondrocyte transplantation (ACT) is one of the few reliable treatment options of cartilage defects with good long-term outcomes. The improvement of ACT led to the matrix-based ACT (MACT). The purpose of the study was to compare two different commercially available MACT systems.     

Significance and technique of autologous chondrocyte transplantation

The bad risk for an early onset of osteoarthritis in the knee increases with the size of a cartilage defect. A collateral meniscus- or ligament-tear will enforce this hazard in addition. In order to avoid such a development, relevant full-thickness cartilage defects should be reconstructed biologically and attendant meniscus- or ligament-tears as well as varus- or valgus deformities should be treated. A number of studies, including some prospective-randomized trials, have shown that autologous chondrocyte transplantation (ACT) is the most reliable procedure for a surgical treatment of full-thickness cartilage defects larger than 4 cm (2) in adults. One disadvantage of ACT is the extensive approach to the joint and often a hypertrophy of the repair tissue. To solve these problems, some different biomaterials for a matrix-assisted ACT have been developed. The scaffold we use has a covering membrane upside and a collagen-sponge carrying the chondrocytes. By means of special surgical instruments a minimally invasive implantation is possible, reducing the side-effects of an extensive approach. Animal studies showed the regeneration of a hyaline cartilage using our described system. However, results of current clinical studies with the different scaffolds must be awaited before an universal application of matrix-assisted ACT can be recommended.     

Cartilage repair: A review of Stanmore experience in the treatment of osteochondral defects in the knee with various surgical techniques

Articular cartilage damage in the young adult knee, if left untreated, it may proceed to degenerative osteoarthritis and is a serious cause of disability and loss of function. Surgical cartilage repair of an osteochondral defect can give the patient significant relief from symptoms and preserve the functional life of the joint. Several techniques including bone marrow stimulation, cartilage tissue based therapy, cartilage cell seeded therapies and osteotomies have been described in the literature with varying results. Established techniques rely mainly on the formation of fibro-cartilage, which has been shown to degenerate over time due to shear forces. The implantation of autologous cultured chondrocytes into an osteochondral defect, may replace damaged cartilage with hyaline or hyaline-like cartilage. This clinical review assesses current surgical techniques and makes recommendations on the most appropriate method of cartilage repair when managing symptomatic osteochondral defects of the knee. We also discuss the experience with the technique of autologous chondrocyte implantation at our institution over the past 11 years.     

细胞载体作为软骨修复中的下一代细胞疗法

背景自从第一位患者接受培养自体软骨细胞移植 （ACI） 以来已过去20多年,新型的软骨修复细胞疗法已经出现.自体培养软骨细胞是第一代细胞疗法,它使用的是混悬培养的自体软骨细胞结合骨膜修补.胶原膜覆盖ACI （CACI）是第二代细胞疗法,它使用的是接种了混悬培养软骨细胞的Ⅰ/Ⅲ型胶原膜上.现今,因关节镜移植术的需求而开发出了第三代细胞疗法,也即采用细胞载体或接种了细胞的支架来移植培养的自体软骨细胞.目的 本文综述了目前基质诱导的自体软骨细胞移植 （MACI） 的情况,它是迄今为止使用最广泛的载体系统.本文还探讨了Ⅰ/Ⅲ型胶原膜的特点、与胶原膜相关的细胞行为、手术技术、康复、临床结果和组织修复效果.研究设计 系统回顾.方法通过搜索 Medline 数据库从1949 年成立以来到 2007年12月的数据,找出相关文献;确认出关于细胞行为、制作过程、手术技术和康复方案的基础和临床研究同行评审的文献.具有原始数据以及使用Ⅰ/Ⅲ型胶原膜的基础和临床研究也被纳入.结果 这些研究获得的数据证实使用MACI治疗的患者在临床结果方面有总体改善.观察到视觉模拟疼痛量表（VAS）评分降低（范围在 1.7～5.32 分）,而改良Cincinnati（范围在3.8～34.2分）评分、Lysholm-Gillquist（范围在23.09～47.6分）评分、Tegner-Lysholm（范围在1.39～3.9分）评分和国际膝关节文献委员会分类量表评分（P〈0.05）均有改善.通过关节镜（包括国际软骨修复学会评分）、MRI 和组织学评估,患者也显示出质量良好的（透明样）组织修复,并且术后并发症发生率较低.结论本综述的结果提示：第三代细胞疗法MACI 程序在治疗有症状的、全层关节软骨缺损修复方面是一种大有前景的方法.     

Evaluation of autologous chondrocyte transplantation via a collagen membrane in equine articular defects: results at 12 and 18 months

OBJECTIVE: To evaluate a technique of autologous chondrocyte implantation (ACI) similar to the other techniques using cell-seeded resorbable collagen membranes in large articular defects. METHODS: Autologous cartilage was harvested arthroscopically from the lateral trochlear ridge of the femur in fifteen 3-year-old horses. After culture and expansion of chondrocytes the newly created ACI construct (autologous chondrocytes cultured expanded, seeded on a collagen membrane, porcine small intestine submucosa) was implanted into 15mm defects on the medial trochlear ridge of the femur in the opposite femoropatellar joint. Using two defects in each horse, the ACI technique was compared to collagen membrane alone (CMA) and empty cartilage defects (ECDs). RESULTS: Arthroscopic evaluations at 4, 8, 12 and 18 months demonstrated that CMA was significantly worse compared to ACI or ECD treatments, with ACI having the best overall subjective grade. Overall raw histological scores demonstrated a significant improvement with ACI compared to either CMA or ECD treated defects and ACI defects had significantly more immunohistochemical staining for aggrecan than CMA or ECD treated defects (with significantly more type II collagen in ACI and ECD compared to CMA defects) at 12 and 18 months. CONCLUSIONS: Histologic and immunohistochemistry results from this long-term randomized study are particularly encouraging and demonstrate superiority with the ACI technique. Although there is no comparable study published with the traditional ACI technique in the horse (or with such a large defect size in another animal model), the use of a solid autologous cell-seeded-constructed implant would appear to offer considerable clinical advantages.     

The role of autologous chondrocyte implantation in the treatment of symptomatic chondromalacia patellae

Purpose

Chondromalacia patella is a distinct clinical entity of abnormal softening of the articular cartilage of the patella, which results in chronic retropatellar pain. Its aetiology is still unclear but the process is thought to be a due to trauma to superficial chondrocytes resulting in a proteolytic enzymic breakdown of the matrix. Our aim was to assess the effectiveness of autologous chondrocyte implantation on patients with a proven symptomatic retropatellar lesion who had at least one failed conventional marrow-stimulating therapy.

Methods

We performed chondrocyte implantation on 48 patients: 25 received autologous chondrocyte implantation with a type I/III membrane (ACI-C) method (Geistlich Biomaterials, Wolhusen, Switzerland), and 23 received the Matrix-assisted Chondrocyte Implantation (MACI) technique (Genzyme, Kastrup, Denmark).

Results

Over a mean follow-up period of 40.3 months, there was a statistically significant improvement in subjective pain scoring using the visual analogue scale (VAS) and objective functional scores using the Modified Cincinnati Rating System (MCS) in both groups.

Conclusions

Chondromalacia patellae lesions responded well to chondrocyte implantation. Better results occurred with MACI than with ACI-C. Excellent and good results were achieved in 40% of ACI-C patients and 57% of MACI patients, but success of chondrocyte implantation was greater with medial/odd-facet lesions. Given that the MACI procedure is technically easier and less time consuming, we consider it to be useful for treating patients with symptomatic chondral defects secondary to chondromalacia patellae.     

Collagen-covered versus matrix-induced autologous chondrocyte implantation for osteochondral defects of the knee: a comparison of tourniquet times

We have compared tourniquet times of two techniques of autologous chondrocyte implantation (ACI). Seventy-three patients underwent the collagen covered ACI technique (ACI-C) and 63 patients underwent the matrix-induced autologous chondrocyte implantation technique (MACI) for symptomatic osteochondral defects of the knee, at our centre, as part of a prospective trial. The mean tourniquet time in the ACI-C group was 80.7 min (range 47–126), and 61.5 min (range 27–100) in the MACI group, P=0.003. Tourniquet times greater than 90 min were required in 22 (31%) ACI procedures and 1 (2%) MACI procedure. The reduced implantation time for the MACI procedure is a clinically significant advantage, and allows cartilage resurfacing to be performed in combination with other techniques within safe tourniquet times.