Autologous chondrocyte implantation drives early chondrogenesis and organized repair in extensive full‐ and partial‐thickness cartilage defects in an equine model

Autologous chondrocyte implantation (ACI) has been used clinically for over 15 years and yet definitive evidence of chondrocyte persistence and direct impact on cartilage repair in full‐thickness lesions is scant and no data are available on ACI in partial‐thickness defects in any animal model. This study assessed the effect of chondrocytes secured using periosteal overlay in partial‐ and full‐thickness cartilage defects in the equine model. Paired cartilage defects 15 mm in diameter were made in the patellofemoral joint of 16 horse and repaired with ACI or periosteal flap alone. Response was assessed at 8 weeks by clinical, microradiographic, and histologic appearance, and by collagen type II immunohistochemistry, and proteoglycan and DNA quantification. ACI improved histologic scores in partial‐ and full‐thickness cartilage defects, including defect filling, attachment to the underlying subchondral bone, and presence of residual chondrocyte accumulations. For partial‐thickness defects chondrocyte predominance, collagen type II content, and toluidine stained matrix were enhanced, and attachment to the surrounding cartilage improved. DNA and PG content of grafted partial‐thickness defects was improved by chondrocyte implantation. Periosteal patches alone did not induce cartilage repair. This study indicated implantation of chondrocytes to cartilage defects improved healing with a combination of persisting chondrocyte regions, enhanced collagen type II formation, and better overall cartilage healing scores. Use of ACI in the more challenging partial‐thickness defects also improved histologic indices and biochemical content. The equine model of cartilage healing closely resembles cartilage repair in man, and results of this study confirm cell persistence and improved early cartilage healing events after ACI. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1121–1130, 2011     

Assessment of Cartilage Repair Quality With the International Cartilage Repair Society Score and the Oswestry Arthroscopy Score

The International Cartilage Repair Society (ICRS) score and the Oswestry Arthroscopic Score (OAS) have been validated to evaluate repair tissue quality. However, the performance of these scores has not been studied in typical patients undergoing cartilage repair and who have lesions of varying sizes. In this study, we compared the performance of the ICRS and the OAS scores and analyzed the effect of lesion characteristics on the performance of these two scores. Cartilage repair quality was assessed in a total of 104 arthroscopic observations of cartilage repair sites of the knee in 62 patients after autologous chondrocyte implantation. Two observers scored the repair areas independently with the ICRS and the OAS scores. The performance of both scores was evaluated according to internal consistency and inter-rater reliability and correlation between the scores. The frequency and proportion of disagreements were analyzed according to the repair site area and the given score. The correlation between the scores was good (r = 0.91, 95% confidence interval [CI]: 0.87–0.94). Both scores showed moderate internal consistency and inter-rater reliability. Cronbach's α was 0.88 (95% CI: 0.80–0.92) for the ICRS score and 0.79 (95% CI: 0.70–0.86) for the OAS score. The intraclass correlation coefficient was 0.89 (95% CI: 0.84–0.92) for the ICRS and 0.81 (95% CI: 0.74–0.87) for the OAS scores. The frequency and proportion of disagreements were higher in larger repair sites. In arthroscopic use, both ICRS and OAS scores perform similarly, however, their reliability deteriorates as the lesion size increases. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:555–562, 2020     

Cartilage repair techniques of the talus: An update

Symptomatic chondral or osteochondral defects of the talus reduce the quality of life of many patients. Although their pathomechanism is well understood, it is well known that different aetiologic factors play a role in their origin. Additionally, it is well recognised that the talar articular cartilage strongly differs from that in the knee. Despite this fact, many recommendations for the management of talar cartilage defects are based on approaches that were developed for the knee. Conservative treatment seems to work best in paediatric and adolescent patients with osteochondritis dissecans. However, depending on the size of the lesions, surgical approaches are necessary to treat many of these defects. Bone marrow stimulation techniques may achieve good results in small lesions. Large lesions may be treated by open procedures such as osteochondral autograft transfer or allograft transplantation. Autologous chondrocyte transplantation, as a restorative procedure, is well investigated in the knee and has been applied in the talus with increasing popularity and promising results but the evidence to date is poor. The goals of the current article are to summarise the different options for treating chondral and osteochondral defects of the talus and review the available literature.     

Cartilage repair evolution in post-traumatic osteochondral lesions of the talus: from open field autologous chondrocyte to bone-marrow-derived cells transplantation

The aims of this study are to describe evolution in cartilage repair from open field autologous chondrocyte implantation to regeneration by arthroscopic bone-marrow-derived cells (BMDCs) “one step” technique; to present the results of a series of patients consecutively treated and to compare in detail the different techniques used in order to establish the advantages obtained with the evolution in cartilage regenerative methods.81 patients (mean age 30 ± 8 years) were evaluated in this study. Patient assessment included clinical AOFAS score, X-rays and MRI preoperatively and at different established follow-ups. All the lesions were >1.5 cm² and received open autologous chondrocyte implantation (10 cases), arthroscopic autologous chondrocyte implantation (46 cases), and “one step” arthroscopic repair by BMDC transplantation (25 cases). For arthroscopic repair techniques a hyaluronic acid membrane was used to support cells and specifically designed instrumentation was developed. Patients of all the three groups underwent a second arthroscopy with a bioptic cartilage harvest at 1 year follow-up.Mean AOFAS score before surgery was 57.1 ± 17.2 and 92.6 ± 10.5 (P < 0.0005) at mean 59.5 ± 26.5 months. A similar pattern of AOFAS improvement in results was found in the three different techniques. Histological evaluations highlighted collagen type II and proteoglycan expression.The cartilage repair techniques described were able to provide a repair tissue which closely approximates the characteristics of the naive hyaline cartilage. Evolution in surgical technique, new biomaterials and more recently the use of BMDCs permitted a marked reduction in procedure morbidity and costs up to a “one step” technique able to overcome all the drawbacks of previous repair techniques.     

Autologous chondrocyte implantation for the treatment of retropatellar cartilage defects: clinical results referred to defect localisation

Introduction  Although autologous chondrocyte implantation (ACI) has become well established for the treatment of full-thickness cartilage defects of the knee joint, nevertheless clinical results of retropatellar lesions are still inferior compared to those of defects located on femoral condyles. We report the clinical results obtained in 70 patients treated with ACI for full-thickness defects of the patella, with special reference to defect location and size, age, body mass index and sports activity. Methods  At a follow-up of 38.4 months (range 14–64, follow-up rate 83.3%), patients’ subjective functional knee scores (IKDC, Lysholm) were analysed, as were the results of objective examination (according to ICRS). Results  Mean patient age at the time of surgery was 34.3 years (±10.1). The mean Lysholm score at the time of follow-up was 73.0 (±22.4) and the subjective IKDC score was 61.6 (±21.5); normal and nearly normal clinical results according to the objective criteria of the International Cartilage Research Society (ICRS) were achieved in 67.1% of the patients, while abnormal results were achieved in 20.0% of the patients and severely abnormal results, in 12.9%. While different surgical techniques did not seem to have any significant influence on the treatment results, both defect size and defect location within the patella were found to be significantly associated with clinical outcome. The corollaries to this are that larger cartilage lesions of the patella are associated with an inferior outcome (p = 0.007) and that cartilage defects located on the lateral patellar facet are correlated with a better clinical outcome than those located on the medial facet or those involving both facets (p = 0.017). Conclusion  This study demonstrates that within a group of patients treated with ACI for retropatellar cartilage lesion there are significant differences in clinical outcome, which are important and should be taken into account of when a decision has to be made on whether or not ACI is indicated.     

微骨折技术结合自体骨软骨碎屑样移植修复兔膝关节软骨缺损的实验研究

目的 评价应用微骨折技术结合自体骨软骨碎屑样团块移植修复兔膝关节软骨缺损的效果. 方法 取健康成年新西兰大白兔46只,随机分为3组:对照组10只,微骨折组18只,实验组18只.制作膝关节软骨缺损模型,对照组不做其他任何处理;微骨折组利用微骨折技术制作网格状微孔;实验组在制作网格状微孔后在缺损表面填盖上碎屑样软骨团块.术后4、8、12周行大体观察、组织学观察及Wakitani组织学评分、糖胺聚糖(GAG)含量测定 结果 术后12周实验组缺损由透明软骨样组织填充,软骨及软骨下骨组织基本恢复,修复的软骨组织在大体观察、组织形态学方面均优于微骨折组和对照组.术后4、8、12周实验组Wakitani组织学评分平均分别为(5.0±1.0)、(6.7±1.5)、(13.0±1.0)分,微骨折组平均分别为(2.3±0.6)、(5.0±1.0)、(7.7±1.2)分,对照组平均分别为(0.0±0.0)、(1.3±0.6)、(1 7±0.6)分,实验组不同时间点评分均高于微骨折组和对照组,差异有统计学意义(P＜0.05).术后4、8、12周实验组GAG含量平均分别为(6.25±0.31)、(13.11±0.21)、(16.23±0 66) μg/mg,微骨折组平均分别为(3.04±0.21)、(5.75±0.24) 、(7.03±0.21) μg/mg,两组比较差异均有统计学意义(P ＜0.05). 结论 微骨折技术结合自体骨软骨碎屑样移植是一种治疗软骨缺损的新选择,其能够有效提高软骨修复的效果.     

自体软骨细胞修复关节软骨缺损的机制探讨

目的:观察团块样自体软骨细胞植入关节软骨缺损后的病理变化,探讨自体软骨细胞移植修复关节软骨缺损的病理生理机制。方法:24只3.0kg以上4～6月龄新西兰大白兔,雌雄不限,随机分为两组:实验组和对照组。实验组12只,20%的速眠新(1mg/kg)肌肉注射麻醉后取肩关节软骨组织,0.2%Ⅱ型胶原酶消化分离软骨细胞,体外单层培养,细胞长成肉眼可见的膜状后收集固体的组织样细胞团,动物再次麻醉制造双膝股骨滑车4.0mm×6.0mm方形缺损,植入细胞团块,骨膜覆盖,缝合骨膜于双股骨髁上。对照组12只,同实验组手术方法进行缺损单纯骨膜移植。1、3、12、24周两组各3只动物空气栓塞处死取材,观察细胞团块变化和缺损修复情况。结果:1周时软骨细胞朝向关节面部分细胞变大变圆,产生大量基质;3周时此种变化更加明显,但骨膜与细胞团块已然不能分开;12周时缺损为类透明软骨组织修复;24周时修复组织为透明软骨样组织,对照组为纤维软骨组织修复。结论:关节软骨细胞体外聚集培养形成的细胞团块内的细胞有迁移生长能力;细胞团块移植方法植入的细胞数量大,表型好,细胞在缺损内不会流失;关节软骨缺损修复是由植入的细胞团块生长分化而来;自体关节软骨细胞团块植入关节缺损内后,在关节应力的影响下,先从朝向关节面的一侧逐渐发生细胞成熟分化和软骨基质产生,逐渐完成缺损的修复。     

Treatment of a Focal Articular Cartilage Defect of the Talus with Polymer-Based Autologous Chondrocyte Implantation: A 12-Year Follow-Up Period

Autologous chondrocyte implantation (ACI) is a first-line treatment option for large articular cartilage defects. Although well-established for cartilage defects in the knee, studies of the long-term outcomes of matrix-assisted ACI to treat cartilage defects in the ankle are rare. In the present report, we describe for the first time the long-term clinical and radiologic results 12 years after polymer-based matrix-assisted ACI treat a full-thickness talar cartilage defect in a 25-year-old male patient. The clinical outcome was assessed using the visual analog scale and Freiburg ankle score, magnetic resonance imaging evaluation using the Henderson-Kreuz scoring system and T2 mapping. Clinical assessment revealed improved visual analog scale and Freiburg ankle scores. The radiologic analysis and T2 relaxation time values indicated the formation of hyaline-like repair tissue. Polymer-based autologous chondrocytes has been shown to be a safe and clinically effective long-term treatment of articular cartilage defects in the talus.     

Quantitative analysis of gene expression in human articular chondrocytes assigned for autologous implantation

Autologous chondrocyte implantation (ACI) relies on the implantation of in vitro expanded cells. The aim was to study the dedifferentiation of human articular chondrocytes under different cultivating conditions [days 0–10 in the primary culture (P0); passages in a monolayer from P0 to P3; monolayer vs. alginate and monolayer vs. alginate/agarose hydrogels] using real‐time PCR analysis. The relative gene expressions for collagen type I and II, aggrecan and versican were quantified and the corresponding differentiation indexes (Col2/Col1, Agr/Ver) were calculated. The values of both differentiation indexes decreased exponentially with time in the P0 monolayer culture, and continued with a significant decrease over the subsequent monolayer passages. On the contrary, the chondrocytes seeded in either of the hydrogels significantly increased the indexes compared to their parallel monolayer cultures. These results indicate that alginate and alginate/agarose hydrogels offer an appropriate environment for human articular chondrocytes to redifferentiate after being expanded in vitro. Therefore the three‐dimensional (3D) hydrogel chondrocyte cultures present not only surgical, but also biological advantage over the classic suspension–periosteum chondrocyte implantation. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:847–853, 2008     

Cartilage repair with osteochondral autografts in sheep: Effect of biophysical stimulation with pulsed electromagnetic fields

The effect of pulsed electromagnetic fields (PEMFs) on the integration of osteochondral autografts was evaluated in sheep. After osteochondral grafts were performed, the animals were treated with PEMFs for 6 h/day or sham‐treated. Six animals were sacrificed at 1 month. Fourteen animals were treated for 2 months and sacrificed at 6 months. At 1 month, the osteogenic activity at the transplant–host subchondral bone interface was increased in PEMF‐treated animals compared to controls. Articular cartilage was healthy in controls and stimulated animals. At 6 months, complete resorption was observed in four control grafts only. Cyst‐like resorption areas were more frequent within the graft of sham‐treated animals versus PEMF‐treated. The average volume of the cysts was not significantly different between the two groups; nevertheless, analysis of the variance of the volumes demonstrated a significant difference. The histological score showed no significant differences between controls and stimulated animals, but the percentage of surface covered by fibrous tissue was higher in the control group than in the stimulated one. Interleukin‐1 and tumor necrosis factor‐α concentration in the synovial fluid was significantly lower, and transforming growth factor‐β1 was significantly higher, in PEMF‐treated animals compared to controls. One month after osteochondral graft implantation, we observed larger bone formation in PEMF‐treated grafts which favors early graft stabilization. In the long term, PEMF exposure limited the bone resorption in subchondral bone; furthermore, the cytokine profile in the synovial fluid was indicative of a more favorable articular environment for the graft. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:631–642, 2008     

Cell-based treatment of osteochondral defects in the rabbit knee with natural and synthetic matrices: cellular seeding determines the outcome

Introduction: Matrix-associated transplantation of cartilage constructs is an appealing method in cartilage repair. Three different matrices seeded with allogenic chondrocytes were compared in an osteochondral defect model in the rabbit. An investigation was conducted to identify the best matrix for cell-based treatment of osteochondral defects in the rabbit knee joint. Materials and methods: Osteochondral defects (diameter 3 mm) were created in the trochlea and the femoral condyles of 33 New Zealand White rabbits, which were then treated with bioartificial cartilage constructs. The cartilage constructs were created in vitro using three different resorbable carrier materials (two fleece matrices: one of PLLA, and one composite of polydioxanon/polyglactin, as well as one consisting of lyophilized dura) cultured with isolated allogenic chondrocytes. The defects were evaluated macroscopically, by histological and immunhistological techniques, and by scanning electron microscopy after 6 weeks, 6 months, and 12 months. The chondrocyte-seeded constructs were compared to defects treated with carrier material alone as well as to untreated control defects. Results: There was a significant improvement in defect repair quality in the transport materials, which were cultured with chondrocytes prior to implantation (P<0.0005). No significant differences were observed between the three carrier matrices, and no significant differences were seen between the unseeded matrices and the untreated control defects. Conclusion: There is no difference in the outcome between the three tested matrices in the treatment of osteochondral defects in the rabbit knee. The results of this in vitro experiment are promising and with refinement may lead to useful clinical therapies.     

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。     

Pulsing direct current-induced repair of articular cartilage in rabbit osteochondral defects

Osteochondral defects in the distal femoral condyles of rabbits exposed to a pulsing direct current exhibits an enhanced quality of repair. The signal, with a peak value of 2 microA repeating at 100 Hz, imposed an electric field in the tissue of 20-60 mV/cm2. Maximum efficacy was seen with a shorter period of exposure (40 vs. 160 h) initiated 48 h after surgery for 4 h/day. Repair tissue originated primarily from metaplasia of subchondral elements although hyperplasia of pre-existing chondrocytes at the margins of the defect could be detected. Defects in treated joints contained Safranin O staining material that was histologically similar to a disorganized hyaline cartilage. Central areas of the defects in control animals contained Safranin O-negative material that generally extruded over the surface as a pannus. The edges of nontreated defects also had characteristics of cartilaginous healing, stressing the importance of using serial sectioning techniques in this model of cartilage repair.     

Pridie钻孔术修复膝关节软骨全层缺损的临床疗效观察

目的总结关节镜下Prid ie钻孔术(subchondral drilling)修复膝关节软骨全层缺损的临床疗效。方法回顾性分析1999年11月~2005年7月我所应用Prid ie钻孔术治疗28例(29膝)关节软骨全层缺损的临床资料。关节镜下直径1.0~1.2 mm克氏针在缺损区软骨下骨板上钻孔,钻孔间距尽量小,2~3 mm,以相邻孔间不穿透为度;孔深3~4 mm,以见到脂肪滴或有孔中渗血为度。术后患肢限制负重6~8周并辅以CPM机早期进行功能锻炼。采用Tegner、M eyers、Lysholm膝关节功能评分作为Prid ie钻孔术疗效判定标准。结果Lysholm疗效评价优19例,良5例,差4例,有效率85.7%(24/28)。Tegner评分由术前(1.9±1.2)分提高到术后(4.9±1.9)分(t=10.912,P=0.001),M eyers评分由术前(10.3±1.3)分提高到术后(15.9±2.6)分(t=10.101,P=0.005),Lysholm评分由术前(47.7±12.5)分提高到术后(83.2±15.4)分(t=10.302,P=0.003)。结论关节镜下Prid ie钻孔术修复膝关节关节软骨全层缺损操作简单、创伤小、疗效可靠,是较为实用的关节软骨修复技术。     

Allogenous bone with collagen for repair of deep osteochondral defects

Background

A scaffold for treatment of deep osteochondral defects should be stable, integrate well, and provide a surface for chondrocytes. To meet these demands, a biphasic scaffold of allogenous sterilized bone with a collagen surface was developed. Integration was tested in the sheep model.

Material and methods

Cartilage chips were taken from the nonweight-bearing area of the left knee of 12 sheep and cultured. After 4 wk a second procedure followed and defects of 9.4-mm diameter at the weight-bearing area of the medial femoral condyle of the right knee were created. The sterilized scaffold was inserted and the cultured autologous chondrocytes were dripped onto the surface. After 6 wk, 3 mo, and 6 mo the animals were sacrificed; the explanted femoral condyles were evaluated macroscopically and using histologic, immunohistochemical, and electronmicroscopic methods.

Results

After 6 wk the level of the surface was well preserved, after 3 mo parts of the scaffold were sintered but after 6 mo the surface was continuous. Full integration of the allogenous bone could be observed after 6 mo. The surface of the scaffold after 6 wk consisted of bone, but after 3 mo some chondrocytes and after 6 mo a continuous chondral layer could be detected.

Conclusions

The biphasic scaffold of allogenous bone and collagen proved to be stable and sufficiently integrated in the short- and midterm interval. Whether the chondrocytes on the surface had been derived from implanted chondrocytes or the scaffold with its surface was sufficiently chondroconductive must be answered in further investigations.     

自体软骨-软骨膜移植重建手指关节面11例

目的:自行设计应用自体软骨-软骨膜复合物进行移植,修复手指关节的软骨缺损,达到重建关节面的目的。方法:2005年10月至2009年10月治疗11例手外伤患者,其中男7例,女4例;年龄17～50岁,平均29岁;均伴有严重手指关节毁损。进行自体软骨-软骨膜移植术,术后指导其进行适当的功能锻炼。术后按手部关节的综合评分法进行评分。结果:全部患者获得随访,时间1～4年,平均24个月。手术全部成功,无感染出现。术后2年随访,手部关节综合评分平均(41.0±0.63)分;其中优(38分)8例,良(35～38分)2例,差(30分)1例。结论:自体软骨-软骨膜复合物移植术,对关节软骨毁损的修复重建功能效果好,减少了手部外伤的伤残率。