Autologous chondrocyte implantation in the knee using fibrin

Outcomes following gel-based autologous chondrocyte implantation for articular cartilage defects of the knee

BACKGROUND

Gel-based autologous chondrocyte implantation (GACI) enables a simpler and more effective delivery of chondrocytes with reproducible three-dimensional structural restoration of the articular cartilage surface. There is limited documentation of medium-term outcomes. This study assessed safety and effectiveness of GACI for treatment of cartilage defects of the knee.

METHODS

This multicentric retrospective study was conducted across eight hospitals in India. Patients who had undergone GACI (CARTIGROW®) between 2008 and 2014 for the treatment of focal articular cartilage defects of the knee (mean defect size 4.5 ± 5.8 cm2) in limbs with normal alignment were analyzed. Primary outcomes were changes in Lysholm Knee Scoring Scale score, and Knee Outcome Sports Activity Scale (SAS).

RESULTS

A total of 107 patients (110 knee joints) with mean age 31.0 ± 10.5 years were included. The mean follow-up was 9.8 ± 1.5 years (range 7.85-13.43). Majority had osteochondritis dissecans (n = 51; 46.4%). The mean Lysholm Knee Scoring Scale score (81.23 ± 13.21 vs. 51.32 ± 17.89; p < 0.0001) and SAS score (80.93 ± 8.26 vs. 28.11 ± 12.28; p < 0.0001) improved significantly at follow-up as compared to pre-operative. Magnetic Resonance Observation of Cartilage Repair Tissue score in 39 patients at minimum 2 years follow-up was 84.5 ± 4.3. Among 30 patients who were playing sports before treatment, 17 patients (56.7%) could return to the same or higher level of sports post-transplantation. No major intra-operative or post-operative complications were noted. Four patients warranted revision surgery.

CONCLUSION

GACI is an effective treatment option for large focal articular cartilage defects of the knee with a low complication rate and revision rate and significant improvement in functional scores.

Progress and prospect of technical and regulatory challenges on tissue-engineered cartilage as therapeutic combination product

Hyaline cartilage plays a critical role in maintaining joint function and pain. However, the lack of blood supply, nerves, and lymphatic vessels greatly limited the self-repair and regeneration of damaged cartilage, giving rise to various tricky issues in medicine. In the past 30 years, numerous treatment techniques and commercial products have been developed and practiced in the clinic for promoting defected cartilage repair and regeneration. Here, the current therapies and their relevant advantages and disadvantages will be summarized, particularly the tissue engineering strategies. Furthermore, the fabrication of tissue-engineered cartilage under research or in the clinic was discussed based on the traid of tissue engineering, that is the materials, seed cells, and bioactive factors. Finally, the commercialized cartilage repair products were listed and the regulatory issues and challenges of tissue-engineered cartilage repair products and clinical application would be reviewed.

•

Tissue engineered cartilage, a promising strategy for articular cartilage repair.

•

Nearly 20 engineered cartilage repair products in clinic based on clinical techniques.

•

Combination product, the classification of tissue-engineered cartilage.

•

Key regulatory compliance issues for combination products.

Collagen Scaffold Application in Arthroscopic Reconstruction of Osteochondral Lesions of the Talus With Autologous Cancellous Bone Grafts

Background

Single-step all-arthroscopic techniques have gained popularity recently in the treatment of osteochondral lesions of the talus (OLT). Concomitant subchondral bone defects led surgeons to add autologous bone grafting to the surgical procedures. Collagen scaffolds have been used widely for stabilization of the reconstruction and regeneration of the articular surface.

Purpose

To compare single-step all-arthroscopic treatment of OLT consisting of debridement, microfracture, autologous bone grafting, and application of fibrin sealant in 2 patient groups: with versus without collagen scaffold.

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 94 patients who underwent single-step all-arthroscopic treatment for OLT. Autologous bone grafting was applied to 48 patients (BG group), while autologous bone grafting plus collagen scaffold was applied to 46 patients (BG+S group). A fibrin sealant was applied to both groups. Clinical outcomes were assessed with the American Orthopaedic Foot & Ankle Society (AOFAS) score and the visual analog scale (VAS) for pain. Radiological outcomes were evaluated with the magnetic resonance observation of cartilage repair tissue score. The mean follow-up time was 69.3 ± 20.7 months.

Results

Patients in both groups showed statistically significant improvement in pre- to postoperative AOFAS and VAS scores (P < .001 for all), with no difference between groups in AOFAS and VAS score improvement. Complete healing with or without hypertrophy was achieved in 42 patients in the BG group (87.5%) and 38 patients in the BG+S group (82.6%).

Conclusion

The treatment of bone lesions in OLT may be the ultimate goal to obtain successful outcomes, in which case using a collagen scaffold besides grafting may not affect clinical and radiological outcomes.

Physical, Mechanical, and Biological Properties of Fibrin Scaffolds for Cartilage Repair

Articular cartilage is a highly organized tissue that provides remarkable load-bearing and low friction properties, allowing for smooth movement of diarthrodial joints; however, due to the avascular, aneural, and non-lymphatic characteristics of cartilage, joint cartilage has self-regeneration and repair limitations. Cartilage tissue engineering is a promising alternative for chondral defect repair. It proposes models that mimic natural tissue structure through the use of cells, scaffolds, and signaling factors to repair, replace, maintain, or improve the specific function of the tissue. In chondral tissue engineering, fibrin is a biocompatible biomaterial suitable for cell growth and differentiation with adequate properties to regenerate damaged cartilage. Additionally, its mechanical, biological, and physical properties can be enhanced by combining it with other materials or biological components. This review addresses the biological, physical, and mechanical properties of fibrin as a biomaterial for cartilage tissue engineering and as an element to enhance the regeneration or repair of chondral lesions.

In Vivo Cartilage Regeneration with Cell-Seeded Natural Biomaterial Scaffold Implants: 15-Year Study

Articular cartilage can be easily damaged from human's daily activities, leading to inflammation and to osteoarthritis, a situation that can diminish the patients' quality of life. For larger cartilage defects, scaffolds are employed to provide cells the appropriate three-dimensional environment to proliferate and differentiate into healthy cartilage tissue. Natural biomaterials used as scaffolds, attract researchers' interest because of their relative nontoxic nature, their abundance as natural products, their easy combination with other materials, and the relative easiness to establish Marketing Authorization. The last 15 years were chosen to review, document, and elucidate the developments on cell-seeded natural biomaterials for articular cartilage treatment in vivo. The parameters of the experimental designs and their results were all documented and presented. Considerations about the newly formed cartilage and the treatment of cartilage defects were discussed, along with difficulties arising when applying natural materials, research limitations, and tissue engineering approaches for hyaline cartilage regeneration.

Combination of preconditioned adipose-derived mesenchymal stem cells and platelet-rich plasma improves the repair of osteoarthritis in rat

Aim: To observe the combined effect of platelet-rich plasma (PRP) and preconditioned adipose-derived mesenchymal stem cells (ADMSCs) on the injured articular cartilage of the rat. Materials & methods: Animals in the study received an intra-articular injection of PRP and preconditioned ADMSCs, both in combination and separately. The response to therapeutic intervention was evaluated by inflammatory markers, proteoglycans content, chondrogenesis and gene expression analyses. Results: The combined therapy resulted in a reduction of IL-6 and TNF-α, increased proteoglycan content of the articular cartilage, upregulation of Acan, Col2a1 and PCNA genes. Downregulation of Col1a1, Col10a1 and Casp3 genes was observed as compared with the untreated osteoarthritis rat model. Conclusion: PRP potentiates the effects of ADMSCs on the repair of damaged articular cartilage.

Clinical, radiological, and histological outcomes after the fibrin-matrix autologous chondrocyte implantation for chondral lesions of the knee in patients more than 50 years old: A prospective case series with minimum 2-year follow-up

BACKGROUND

The purpose of this study was to evaluate clinical and radiological outcomes and to analyze the histological findings of repaired cartilage in patients more than 50 years old with underwent fibrin-matrix autologous chondrocyte implantation (ACI).

METHODS

From January 2013 to February 2014, a prospective study was conducted on 16 patients (16 knees) who underwent fibrin-matrix ACI for International Cartilage Repair Society grade 3 or 4 chondral lesions of the knee. The major lesion was in the medial femoral condyle in all patients. The mean age of the patients was 58.1 ± 6.2 (range 51-66) years, and the minimum follow-up period was 2 years. All patients had clinical and radiological evaluations at 3 months, 6 months, 1 year, and 2 years after surgery. Twelve patients had second-look arthroscopies at 1 year after surgery, and implanted chondral biopsies were performed in 11 of these 12 patients for histological analysis.

RESULTS

Functional disability assessment scales for the knee significantly improved after fibrin-matrix ACI (p < 0.05). The visual analog scale score significantly decreased from 6.7 ± 1.2 to 2.0 ± 1.8 (p < 0.001). The mean modified magnetic resonance observation of cartilage repair tissue score was 83.8 ± 17.3 at 1 year after surgery and 74.0 ± 19.2 at 2 years after surgery. Repair of the tissue with hyaline cartilage was confirmed histologically.

CONCLUSIONS

Satisfactory clinical and radiological outcomes were obtained from gel-type fibrin-matrix ACI technique in older patients with a cartilage defect of the knee. Histological analysis confirmed that the new repaired tissue with hyaline cartilage filled the cartilage defect area. Therefore, fibrin-matrix ACI is believed to be an applicable treatment for older patients with chondral lesions of the knee.

LEVEL OF EVIDENCE

Level IV.

MODERN TRENDS IN THE TREATMENT OF FOCAL CARTILAGE DEFECTS OF THE KNEE

The article is devoted to the current trend of modern orthopedics – the surgical treatment of local full-thickness defects in the hyaline cartilage of the knee joint. This pathology is diagnosed in 5-10% of patients with diseases and injuries of the knee joint.Materials and methods: The authors of the article presented one of the most modern and available technologies for the restoration of cartilage defects – the technology of matrix-induced autochondrogenesis (AMIC – autologous matrix-induced chondrogenesis). This operation technique was used in 63 patients. The article presents the indications and technique of surgery, considers possible errors, complications, criteria for evaluating treatment outcomes.Results: treatment outcomes in terms of up to 13 years were studied in 56 patients. Good treatment results were observed in 53 patients. In all cases, high-quality and regeneration of the cartilaginous surface of the femoral condyles was achieved.Conclusion: Analysis of the outcomes of treatment of patients after implantation of collagen membranes in various modifications allows the authors of the article to recommend this technique for widespread use in clinical practice.

Arthroscopic gel-type autologous chondrocyte implantation presents histologic evidence of regenerating hyaline-like cartilage in the knee with articular cartilage defect

PURPOSE

To investigate the clinical, radiological, and histological results of arthroscopic gel-type autologous chondrocyte implantation (GACI) in treating chondral defects of the knee.

METHODS

This study prospectively examined five males and five females with a mean age of 40.3 ± 10.3 years who underwent arthroscopic GACI between March 2012 and February 2013. The gel comprised a mixture of 1 ml of fibrinogen plus 0.1-0.2 ml of thrombin. The mean size of chondral defect was 2.9 ± 1.2 cm² (range 1.2-5.4 cm²). International knee documentation committee (IKDC) subjective score, knee injury and osteoarthritis outcome score (KOOS), knee society score, and visual analog scale (VAS) for pain were assessed preoperatively and during regular follow-up examinations performed for up to 5 years postoperatively. Serial magnetic resonance imaging was performed for up to 2 years after the surgery to observe healing, using the modified magnetic resonance observation of cartilage repair tissue (MOCART) score. In eight patients, second-look arthroscopy was performed at 1 year after the implantation to assess the status of treated cartilage, and a portion of regenerated cartilage was harvested for histologic evaluation.

RESULTS

The mean VAS score (p = 0.045), IKDC subjective score (p = 0.041), KOOS pain (p = 0.025), KOOS activities of daily living (p = 0.048), and KOOS quality of life (p = 0.029) showed significant improvement at 5 years after the surgery. The modified MOCART evaluation showed that the scores were 59.5 ± 29.4 and 85.0 ± 8.0 at 12 weeks and 2 years after the operation, respectively. Histologic examination demonstrated a mean regenerated cartilage thickness of 3.5 ± 0.8 mm and a mean Oswestry score of 8.2 ± 1.8. Immunohistochemistry analysis showed that the expression of collagen type II was more evident and more evenly distributed than collagen type I in regenerated cartilage. There was a significant correlation between Oswestry score and change in VAS scale from postoperative 2-5 years.

CONCLUSIONS

Arthroscopic GACI produces satisfactory clinical and radiologic outcomes, and histologic evaluation confirms sufficient regeneration of hyaline-like cartilage that correlates with improved symptoms. Therefore, it is an acceptable, minimally invasive, and technically simple option for the restoration of cartilage defects of the knee.

LEVEL OF EVIDENCE

IV.

The Use of Nanomaterials in Tissue Engineering for Cartilage Regeneration; Current Approaches and Future Perspectives

The repair and regeneration of articular cartilage represent important challenges for orthopedic investigators and surgeons worldwide due to its avascular, aneural structure, cellular arrangement, and dense extracellular structure. Although abundant efforts have been paid to provide tissue-engineered grafts, the use of therapeutically cell-based options for repairing cartilage remains unsolved in the clinic. Merging a clinical perspective with recent progress in nanotechnology can be helpful for developing efficient cartilage replacements. Nanomaterials, < 100 nm structural elements, can control different properties of materials by collecting them at nanometric sizes. The integration of nanomaterials holds promise in developing scaffolds that better simulate the extracellular matrix (ECM) environment of cartilage to enhance the interaction of scaffold with the cells and improve the functionality of the engineered-tissue construct. This technology not only can be used for the healing of focal defects but can also be used for extensive osteoarthritic degenerative alterations in the joint. In this review paper, we will emphasize the recent investigations of articular cartilage repair/regeneration via biomaterials. Also, the application of novel technologies and materials is discussed.

Gold nanoparticles for the in situ polymerization of near-infrared responsive hydrogels based on fibrin

Non-invasiveness and relative safety of photothermal therapy, which enables local hyperthermia of target tissues using a near infrared (NIR) laser, has attracted increasing interest. Due to their biocompatibility, amenability of synthesis and functionalization, gold nanoparticles have been investigated as therapeutic photothermal agents. In this work, hollow gold nanoparticles (HGNP) were coated with poly-l-lysine through the use of COOH-Poly(ethylene glycol)-SH as a covalent linker. The functionalized HGNP, which peak their surface plasmon resonance at 800 nm, can bind thrombin. Thrombin-conjugated HGNP conduct in situ fibrin polymerization, facilitating the process of generating photothermal matrices. Interestingly, the metallic core of thrombin-loaded HGNP fragmentates at physiological temperature. During polymerization process, matrices prepared with thrombin-loaded HGNP were loaded with genetically-modified stem cells that harbour a heat-activated and ligand-dependent gene switch for regulating transgene expression. NIR laser irradiation of resulting cell constructs in the presence of ligand successfully triggered transgene expression in vitro and in vivo. STATEMENT OF SIGNIFICANCE: Current technological development allows synthesis of gold nanoparticles (GNP) in a wide range of shapes and sizes, consistently and at scale. GNP, stable and easily functionalized, show low cytotoxicity and high biocompatibility. Allied to that, GNP present optoelectronic properties that have been exploited in a range of biomedical applications. Following a layer-by-layer functionalization approach, we prepared hollow GNP coated with a positively charged copolymer that enabled thrombin conjugation. The resulting nanomaterial efficiently catalyzed the formation of fibrin hydrogels which convert energy of the near infrared (NIR) into heat. The resulting NIR-responsive hydrogels can function as scaffolding for cells capable of controlled gene expression triggered by optical hyperthermia, thus allowing the deployment of therapeutic gene products in desired spatiotemporal frameworks.

Comparative Effectiveness of Cartilage Repair With Respect to the Minimal Clinically Important Difference

BACKGROUND

Recent studies demonstrated a 5% increase in cartilage repair procedures annually in the United States. There is currently no consensus regarding a superior technique, nor has there been a comprehensive evaluation of postoperative clinical outcomes with respect to a minimal clinically important difference (MCID).

PURPOSE

To determine the proportion of available cartilage repair studies that meet or exceed MCID values for clinical outcomes improvement over short-, mid-, and long-term follow-up.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic review was performed via the Medline, Scopus, and Cochrane Library databases. Available studies were included that investigated clinical outcomes for microfracture (MFX), osteoarticular transfer system (OATS), osteochondral allograft transplantation, and autologous chondrocyte implantation/matrix-induced autologous chondrocyte implantation (ACI/MACI) for the treatment of symptomatic knee chondral defects. Cohorts were combined on the basis of surgical intervention by performing a meta-analysis that utilized inverse-variance weighting in a DerSimonian-Laird random effects model. Weighted mean improvements in International Knee Documentation Committee (IKDC), Lysholm, and visual analog scale for pain (VAS pain) scores were calculated from preoperative to short- (1-4 years), mid- (5-9 years), and long-term (≥10 years) postoperative follow-up. Mean values were compared with established MCID values per 2-tailed 1-sample Student t tests.

RESULTS

A total of 89 studies with 3894 unique patients were analyzed after full-text review. MFX met MCID values for all outcome scores at short- and midterm follow-up with the exception of VAS pain in the midterm. OATS met MCID values for all outcome scores at all available time points; however, long-term data were not available for VAS pain. Osteochondral allograft transplantation met MCID values for IKDC at short- and midterm follow-up and for Lysholm at short-term follow-up, although data were not available for other time points or for VAS pain. ACI/MACI met MCID values for all outcome scores (IKDC, Lysholm, and VAS pain) at all time points.

CONCLUSION

In the age of informed consent, it is important to critically evaluate the clinical outcomes and durability of cartilage surgery with respect to well-established standards of clinical improvement. MFX failed to maintain VAS pain improvements above MCID thresholds with follow-up from 5 to 9 years. All cartilage repair procedures met MCID values at short- and midterm follow-up for IKDC and Lysholm scores; ACI/MACI and OATS additionally met MCID values in the long term, demonstrating extended maintenance of clinical benefits for patients undergoing these surgical interventions as compared with MFX.

The proper correction of the mechanical axis in high tibial osteotomy with concomitant cartilage procedures-a retrospective comparative study

Background

The guidelines to correct the mechanical axis in high tibial osteotomy (HTO) have changed recently, and some studies have suggested that the correction of the mechanical axis should be based on the severity of cartilage defect. The purpose of this study was (1) to evaluate the radiographic and clinical outcomes of HTO with concomitant cartilage procedures and (2) to compare our method with conventional method regarding the mechanical axis correction.

Methods

Sixty-six knees which underwent opening wedge HTO with cartilage procedures were evaluated retrospectively. The mean age was 56.0 ± 8.3 years, and the average follow-up period was 35.9 ± 22.0 months (range, 24–93 months) with a minimum follow-up of 2 years. All patients were divided into two groups regarding the method of mechanical axis correction; the postoperative mechanical axis was shifted to 50–55% of the tibial plateau width in group I (n = 46) and to 62–66% according to the conventional method in group II (n = 20). Concomitant cartilage procedures were performed, and each technique of those was determined according to the cartilage status.

Results

The functional scores and visual analog scale for pain in all patients showed a significant improvement at the final follow-up, but there was no significant difference between two groups. The postoperative mechanical axis was the valgus axis of 0.7° in group I with average mechanical axis deviation (MAD) of 51.7%, whereas the valgus axis of 4.2° in group II with average MAD of 64.0%. In patients who underwent second-look arthroscopy, the cartilaginous regeneration could be obtained by cartilage procedures.

Conclusion

In HTO with concomitant cartilage procedures, the method to correct postoperative mechanical axis to the neutral or valgus axis less than 3° could be an effective and safe method to obtain reliable clinical outcomes without complications. Therefore, our method can be used as a selective technique to prevent complications related to the postoperative valgus alignment in patients who are needed much correction angle due to the preoperative severe varus alignment.

Study design

Retrospective comparative study, level III.

A Multicenter, Double-Blind, Phase III Clinical Trial to Evaluate the Efficacy and Safety of a Cell and Gene Therapy in Knee Osteoarthritis Patients

The aim of this study was to test the clinical efficacy of TissueGene-C (TG-C), a cell and gene therapeutic for osteoarthritis consisting of non-transformed and transduced chondrocytes (3:1) retrovirally transduced to overexpress transforming growth factor-β1. A total of 163 Kellgren-Lawrence grade 3 patients with knee osteoarthritis were randomly assigned to receive intra-articular TG-C or placebo. Primary efficacy measures included criteria for subjective assessment by International Knee Documentation Committee (IKDC) and pain severity by Visual Analog Scale (VAS) for 52 weeks. Secondary efficacy measures included IKDC and VAS at 26 and 39 weeks; pain, stiffness, and physical function by the Western Ontario and McMaster Universities Arthritis Index (WOMAC); and pain, symptoms, daily activities, function in sports and recreation, and quality of life by the Knee Injury and Osteoarthritis Outcome Score (KOOS), X-ray, magnetic resonance imaging, and soluble urine and blood biomarkers. TG-C was associated with statistically significant improvement over placebo in the total IKDC score and individual categories, and in the VAS score at 26, 39, and 52 weeks. WOMAC and KOOS scores also improved with TG-C over placebo. Patients treated with TG-C showed trends directed toward thicker cartilage and slower growing rates of subchondral bone surface area in the medial tibia, lateral tibia, lateral patella, and lateral patella femoral regions, although these were not statistically significant (p > 0.05). Serum C-terminal telopeptide of type I collagen (CTX-I) and urine CTX-II levels were lower over 1 year in TG-C than placebo-treated patients, with CTX-I level reaching statistical significance. These tendencies supported TG-C as holding great potential as a disease-modifying osteoarthritis drug. The most frequent adverse events in the TG-C group were peripheral edema (9%), arthralgia (8%), joint swelling (6%), and injection site pain (5%). TG-C was associated with statistically significant improvements in function and pain in patients with knee osteoarthritis. The unexpected adverse events were not observed.

Autologous Bone Marrow Cell Stimulation and Allogenic Chondrocyte Implantation for the Repair of Full-Thickness Articular Cartilage Defects in a Rabbit Model

OBJECTIVE

The aim of this study was to evaluate the results of autologous bone marrow cell stimulation and allogenic chondrocyte implantation using 3-dimensional gel-type fibrin matrix in an animal model.

DESIGN

Eighteen rabbits were divided into 2 treatment groups. One group was treated with a microfracture and covering of it with gel-type fibrin (AutoBMS; n = 9), and the other group was treated with allogenic chondrocytes mixed gel-type fibrin at the cartilage defect (AlloCI; n = 9). The control group was untreated cartilage defect at the other side knee of each object. Twelve weeks after treatment, the cartilage was evaluated using the International Cartilage Repair Society (ICRS) scoring system, immunohistochemical staining, and modified O'Driscoll grading system.

RESULTS

The ICRS scores were similar in the AutoBMS (9.44 ± 2.44) and the AlloCI (9.33 ± 1.67) groups ( P < 0.05). Immunohistochemical staining confirmed higher expression of cartilaginous collagen for both groups. The average difference (AutoBMS, 31.89 ± 6.54; AlloCI, 32.89 ± 5.25) in the modified O'Driscoll scores appeared to be nonsignificant ( P > 0.05); however, both treatment groups showed significantly higher scores with respect to their control group (18.45 ± 1.65; 18.97 ± 1.58) ( P < 0.05).

CONCLUSION

This experimental study suggests autologous bone marrow cells stimulation and implantation of allogenic chondrocytes are both useful methodologies for regenerating hyaline-like cartilage in full-thickness cartilage defects in animal model.

Implant strategy affects scaffold stability and integrity in cartilage treatment

PURPOSE

To identify the most appropriate implantation strategy for a novel chondral scaffold in a model simulating the early post-operative phase, in order to optimize the implant procedure and reduce the risk of early failure.

METHODS

Eight human cadaveric limbs were strapped to a continuous passive motion device and exposed to extension-flexion cycles (0°-90°). Chondral lesions (1.8 cm diameter) were prepared on condyles, patella and trochlea for the implant of a bi-layer collagen-hydroxyapatite scaffold. The first set-up compared four fixation techniques: press-fit (PF) vs. fibrin glue (FG) vs. pins vs. sutures; the second compared circular and square implants; the third investigated stability in a weight-bearing simulation. The scaffolds were evaluated using semi-quantitative Drobnic and modified Bekkers scores.

RESULTS

FG presented higher total Drobnic and Bekkers scores compared to PF (both p = 0.002), pins (p = 0.013 and 0.001) and sutures (p = 0.001 and < 0.0005). Pins offered better total Drobnic and Bekkers scores than PF in the anterior femoral condyles (p = 0.007 and 0.065), similar to FG. The comparison of round and square implants applied by FG showed worst results for square lesions (Drobnic score p = 0.049, Bekkers score p = 0.037). Finally, load caused worst overall results (Drobnic p = 0.018).

CONCLUSIONS

FG improves the fixation of this collagen-HA scaffold regardless of lesion location, improving implant stability while preserving its integrity. Pins represent a suitable option only for lesions of the anterior condyles. Square scaffolds present weak corners, therefore, round implants should be preferred. Finally, partial weight-bearing simulation significantly affected the scaffold. These findings may be useful to improve surgical technique and post-operative management of patients, to optimize the outcome of chondral scaffold implantation.

Nanomaterials/Nanocomposites for Osteochondral Tissue

For many years, the avascular nature of cartilage tissue has posed a clinical challenge for replacement, repair, and reconstruction of damaged cartilage within the human body. Injuries to cartilage and osteochondral tissues can be due to osteoarthritis, sports, aggressive cancers, and repetitive stresses and inflammation on wearing tissue. Due to its limited capacity for regeneration or repair, there is a need for suitable material systems which can recapitulate the function of the native osteochondral tissue physically, mechanically, histologically, and biologically. Tissue engineering (TE) approaches take advantage of principles of biomedical engineering, clinical medicine, and cell biology to formulate, functionalize, and apply biomaterial scaffolds to aid in the regeneration and repair of tissues. Nanomaterial science has introduced new methods for improving and fortifying TE scaffolds, and lies on the forefront of cutting-edge TE strategies. These nanomaterials enable unique properties directly correlated to their sub-micron dimensionality including structural and cellular advantages. Examples include electrospun nanofibers and emulsion nanoparticles which provide nanoscale features for biomaterials, more closely replicating the 3D extracellular matrix, providing better cell adhesion, integration, interaction, and signaling. This chapter aims to provide a detailed overview of osteochondral regeneration and repair using TE strategies with a focus on nanomaterials and nanocomposites.

Advanced Therapy Medicinal Products: A Guide for Bone Marrow-derived MSC Application in Bone and Cartilage Tissue Engineering

Millions of people worldwide suffer from trauma- or age-related orthopedic diseases such as osteoarthritis, osteoporosis, or cancer. Tissue Engineering (TE) and Regenerative Medicine are multidisciplinary fields focusing on the development of artificial organs, biomimetic engineered tissues, and cells to restore or maintain tissue and organ function. While allogenic and future autologous transplantations are nowadays the gold standards for both cartilage and bone defect repair, they are both subject to important limitations such as availability of healthy tissue, donor site morbidity, and graft rejection. Tissue engineered bone and cartilage products represent a promising and alternative approach with the potential to overcome these limitations. Since the development of Advanced Therapy Medicinal Products (ATMPs) such as TE products requires the knowledge of diverse regulation and an extensive communication with the national/international authorities, the aim of this review is therefore to summarize the state of the art on the clinical applications of human bone marrow-derived stromal cells for cartilage and bone TE. In addition, this review provides an overview of the European legislation to facilitate the development and commercialization of new ATMPs.

Chondrogenic Gene Expression Differences between Chondrocytes from Osteoarthritic and Non-OA Trauma Joints in a 3D Collagen Type I Hydrogel

Objective The purpose of the current study was to compare the donor age variation of chondrocytes from non-OA (osteoarthritic) trauma joints in patients of young to middle age (20.5 ± 3.7, 31.8 ± 1.9, 41.9 ± 4.1 years) embedded in matrix-associated autologous chondrocyte transplantation (MACT) grafts (CaReS). The chondrocyte-specific gene expression of CaReS grafts were then compared to chondrocytes from OA joints (in patients aged 63.8 ± 10 years) embedded in a collagen type I hydrogel. Design OA chondrocytes and articular chondrocyte-laden grafts were cultured over 14 days in chondrogenic growth medium. We performed reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) to evaluate the mRNA expression levels of chondrocyte-specific and hypertrophic markers. Results Gene expression analysis with RT-qPCR revealed no significant difference in chondrocyte-specific genes ( COL2A1, ACAN, SOX9, SOX5, SOX6) among 3 different age group of patients with CaReS grafts. In a comparative analysis of OA chondrocytes to articular chondrocytes, chondrogenic markers ( COL2A1, SOX6) exhibited higher expression in OA chondrocytes ( P < 0.05). Hypertrophic or OA cartilage pathogenesis marker ( MMP3, MMP13) expression was higher and COL1A1 had significantly lower expression ( P < 0.05) in OA chondrocytes than articular chondrocytes when cultivated in collagen type I hydrogels. Conclusion In summary, we identify that donor age variation does not influence the chondrogenic gene expression of the CaReS system. We also identified that freshly isolated OA chondrocytes embedded in collagen type I hydrogels can exhibit chondrogenic gene expression as observed in articular chondrocytes on the CaReS grafts. Transforming OA chondrocytes to articular chondrocytes can be regarded as an alternative option in the MACT technique.

Polymers in Cartilage Defect Repair of the Knee: Current Status and Future Prospects

Cartilage defects in the knee are often seen in young and active patients. There is a need for effective joint preserving treatments in patients suffering from cartilage defects, as untreated defects often lead to osteoarthritis. Within the last two decades, tissue engineering based techniques using a wide variety of polymers, cell sources, and signaling molecules have been evaluated. We start this review with basic background information on cartilage structure, its intrinsic repair, and an overview of the cartilage repair treatments from a historical perspective. Next, we thoroughly discuss polymer construct components and their current use in commercially available constructs. Finally, we provide an in-depth discussion about construct considerations such as degradation rates, cell sources, mechanical properties, joint homeostasis, and non-degradable/hybrid resurfacing techniques. As future prospects in cartilage repair, we foresee developments in three areas: first, further optimization of degradable scaffolds towards more biomimetic grafts and improved joint environment. Second, we predict that patient-specific non-degradable resurfacing implants will become increasingly applied and will provide a feasible treatment for older patients or failed regenerative treatments. Third, we foresee an increase of interest in hybrid construct, which combines degradable with non-degradable materials.

Gel-type autologous chondrocyte implantation for cartilage repair in patients with prior ACL reconstruction: A retrospective two year follow-up

PURPOSE

To describe the early patient-reported outcomes of articular cartilage repair in patients with pain due to grade III or IV articular cartilage defects after prior anterior cruciate ligament (ACL) reconstruction.

METHODS

Nineteen patients underwent a gel-type autologous chondrocyte implantation (GACI) procedure after ACL reconstruction. Median timeframe between ACL reconstruction and GACI procedure was 52 months (range 16 to 369). The average age at chondrocyte implantation was 35 (standard deviation (SD) eight) years and average cumulative articular cartilage defect size was nine (SD four) square centimeter. Outcome was assessed prior to the GACI procedure and two years after GACI using the International Knee Documentation Committee (IKDC) score and the Knee injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

Two year post-GACI scores showed a statistically significant improvement of IKDC (13, SD 22, p=.02) and KOOS quality of life (18, SD 27, p=.01) compared to the pre-GACI scores. The other KOOS domains did improve, but not statistically significant. Seven (37%) patients underwent reoperation after the GACI.

CONCLUSION

Patients with prior ACL reconstruction and suffering from ongoing pain associated with cartilage defects can benefit from cartilage repair with GACI.

No outgrowth of chondrocytes from non-digested particulated articular cartilage embedded in commercially available fibrin matrix: an in vitro study

Background

Commercially available fibrin is routinely being used as both a matrix in certain cartilage repair techniques and a method for scaffold fixation. Chondrocytes from non-digested particulated cartilage fragments are proposed as a possible source for new cartilage tissue formation in some operative techniques. The goal of this study was to test that chondrocytes from particulated articular cartilage embedded in fibrin have an active role in the process of cartilage repair, as well as if commercially available fibrin should be used as a suitable matrix.

Methods

Articular cartilage was obtained from patients undergoing total knee replacement surgery. The biopsies were particulated in small, 1–2-mm³ pieces and embedded in fibrin. Two groups were compared in our study, particulated articular cartilage with and without collagenase treatment. The specimens were analyzed by optical microscopy after 2–5 weeks of cultivation in a special construct embedded in a cell culture medium containing particulated cartilage embedded in fibrin in the upper phase and cancellous bone in the lower phase under the perforated nylon membrane.

Results

None of the biopsies taken from four different patients showed the outgrowth of chondrocytes or bone marrow-originated cells into the fibrin matrix in our experimental model.

Conclusions

It has been shown in our experimental model in vitro little to support the theory that articular chondrocytes from particulated articular cartilage embedded in fibrin have an active role in cartilage repair in its early stage.

Autologous collagen induced chondrogenesis (ACIC: Shetty-Kim technique) - A matrix based acellular single stage arthroscopic cartilage repair technique

The defects of articular cartilage in the knee joint are a common degenerative disease and currently there are several established techniques to treat this problem, each with their own advantages and shortcomings. Autologous chondrocyte implantation is the current gold standard but the technique is expensive, time-consuming and most versions require two stage procedures and an arthrotomy. Autologous collagen induced chondrogenesis (ACIC) is a single-stage arthroscopic procedure and we developed. This method uses microfracture technique with atelocollagen mixed with fibrin gel to treat articular cartilage defects. We introduce this ACIC techniques and its scientific background.

Cell-based cartilage repair strategies in the horse

Damage to the articular cartilage surface is common in the equine athlete and, due to the poor intrinsic healing capabilities of cartilage, can lead to osteoarthritis (OA). Joint disease and OA are the leading cause of retirement in equine athletes and currently there are no effective treatments to stop the progression of OA. Several different cell-based strategies have been investigated to bolster the weak regenerative response of chondrocytes. Such techniques aim to restore the articular surface and prevent further joint degradation. Cell-based cartilage repair strategies include enhancement of endogenous repair mechanisms by recruitment of stem cells from the bone marrow following perforation of the subchondral bone plate; osteochondral implantation; implantation of chondrocytes that are maintained in defects by either a membrane cover or scaffold, and transplantation of mesenchymal stem cells into cartilage lesions. More recently, bioengineered cartilage and scaffoldless cartilage have been investigated for enhancing repair. This review article focuses on the multitude of cell-based repair techniques for cartilage repair across several species, with special attention paid to the horse.

Arthroscopic airbrush assisted cell implantation for cartilage repair in the knee: a controlled laboratory and human cadaveric study

OBJECTIVE

The objective of this study was to investigate the feasibility of arthroscopic airbrush assisted cartilage repair.

METHODS

An airbrush device (Baxter) was used to spray both human expanded osteoarthritic chondrocytes and choncrocytes with their pericellular matrix (chondrons) at 1 × 10(6) cells/ml fibrin glue (Tissucol, Baxter) in vitro. Depth-dependent cell viability was assessed for both methods with confocal microscopy. Constructs were cultured for 21 days to assess matrix production. A controlled human cadaveric study (n = 8) was performed to test the feasibility of the procedure in which defects were filled with either arthroscopic airbrushing or needle extrusion. All knees were subjected to 60 min of continuous passive motion and scored on outline attachment and defect filling.

RESULTS

Spraying both chondrocytes and chondrons in fibrin glue resulted in a homogenous cell distribution throughout the scaffold. No difference in viability or matrix production between application methods was found nor between chondrons and chondrocytes. The cadaveric study revealed that airbrushing was highly feasible, and that defect filling through needle extrusion was more difficult to perform based on fibrin glue adhesion and gravity-induced seepage. Defect outline and coverage scores were consistently higher for extrusion, albeit not statistically significant.

CONCLUSION

Both chondrons and chondrocytes can be evenly distributed in a sprayed fibrin glue scaffold without affecting viability while supporting matrix production. The airbrush technology is feasible, easier to perform than needle extrusion and allows for reproducible arthroscopic filling of cartilage defects.

Combination of ADMSCs and chondrocytes reduces hypertrophy and improves the functional properties of osteoarthritic cartilage

OBJECTIVE

To evaluate the therapeutic efficacy of Adipose derived MSCs (ADMSCs) in combination with chondrocytes in counteracting oxidative stress in chondrocytes in vitro and in rat model of osteoarthritis (OA).

METHOD

Cultured chondrocytes were exposed to oxidative stress with 200 μM Hydrogen peroxide (H2O2), followed by co-culture with ADMSCs or chondrocytes or combination of both cell types in a transwell culture system for 36 h. The cytoprotective effect was assessed by immunocytochemistry and gene expression analysis. In vivo study evaluated therapeutic effect of the above mentioned three treatments after transplantation in OA rats.

RESULTS

The Combination of ADMSCs + Chondrocytes decreased the extent of oxidative stress-induced damage of chondrocytes. Enhanced expression level of Acan and Collagen type-II alpha (Col2a1) with a correspondingly decreased expression of Collagen type-I alpha (Col1a1) and Matrix metallopeptidase 13 (Mmp13) was maximally observed in this group. Moreover, reduced count of annexin-V positive cells, Caspase (Casp3) gene expression and Lactate dehydrogenase (LDH) release with concomitantly enhanced viability and expression of proliferating cell nuclear antigen (PCNA) gene was observed. In vivo study showed that homing of cells and proteoglycan contents of knee joints were significantly better in ADMSCs + Chondrocytes transplanted rats. Increased expression of Acan and Col2a1 along with decreased expression of Col1a1 and Mmp13 indicated formation of hyaline cartilage in this group. These rats also demonstrated significantly reduced expression of Casp3 while increased expression of PCNA genes than the other cell transplanted groups.

CONCLUSIONS

Our results demonstrated that a combination of ADMSCs and chondrocytes may be a more effective therapeutic strategy against OA than the use of ADMSCs or chondrocytes separately.

Satisfactory long-term MRI after autologous chondrocyte implantation at the knee

PURPOSE

Autologous chondrocyte implantation (ACI) to address isolated condylar lesions is supposed to limit degenerative deterioration in neutrally aligned knees. Here, we report long-term results of the first-generation ACI technique with periosteal flap.

METHODS

Twelve patients, 29 years old on average, were included on the basis of pre-operative MRI selection of lesions >2 cm2. Cartilage carrots were harvested arthroscopically, then cultured and finally re-implanted within a mean time interval of 12 weeks. Ten-year MRI results were analysed according to a semi-quantitative scale, along with functional assessment based on International Knee Documentation Committee score, Lysholm et al. score and the Tegner et al. activity scale.

RESULTS

One patient secondarily required valgus tibial osteotomy with mosaic plasty. Another incurred graft hypertrophy that necessitated arthroscopic peeling. MRI showed that cartilage repair filled more than 50% of the initial defect in 9 patients. Standard radiographs revealed slight narrowing of the joint line. Overall, functional scores improved durably by 50%, although activity level decreased substantially.

CONCLUSION

ACI contained degenerative changes within moderate stages while maintaining durable functional improvement. However, in the absence of controls, it was difficult to differentiate between these findings and the spontaneous evolution of non-treated lesions.

LEVEL OF EVIDENCE

Case series, Level IV.

Implantation of tissue-engineered cartilage-like tissue for the treatment for full-thickness cartilage defects of the knee

PURPOSE

The purposes of this study were to evaluate early- to midterm clinical results after implantation of tissue-engineered cartilage-like tissue for the treatment for full-thickness cartilage defects of the knee and to identify the factors affecting the final clinical results.

METHODS

Tissue-engineered cartilage-like tissue was prepared by culturing autologous chondrocytes in atelocollagen gel for 3-4 weeks. A total of 73 knees of 72 patients with full-thickness cartilage defects were implanted with this tissue-engineered cartilage-like tissue. The follow-up of these patients for >5 years (range 5-11 years, median 8.0 years) is reported. The patients were evaluated clinically using a rating scale, as well as arthroscopically, biomechanically, and histologically. A modified magnetic resonance observation of cartilage repair tissue (MOCART) system was used to quantify the magnetic resonance imaging (MRI) findings of the lesions. The patient or defect factors influencing the final clinical outcomes were also investigated.

RESULTS

Clinical rating improved significantly after implantation of tissue-engineered cartilage-like tissue. Arthroscopic findings at 2 years after implantation were graded as normal or nearly normal according to the International Cartilage Repair Society (ICRS) scale in 64 of 73 knees (87.7%). Biomechanically, stiffness of the graft almost equalled the surrounding normal cartilage (87.9-102.5%) at 2 years after implantation. Histologically, overall assessment of the repaired tissue by ICRS Visual Assessment Scale II was 70.4 ± 20.8. The average MOCART score was 13.5 ± 11.3 (0-45) preoperatively, 66.6 ± 16.8 (10-90) at 1 year after implantation, 70.4 ± 16.1 (15-90) at 2 years after implantation, and 72.5 ± 17.4 (15-95) at the final follow-up, indicating that MRI results were maintained. Among the factors investigated, only arthroscopic grade of the repaired lesion at 2 years after implantation was significantly correlated with the final clinical scores.

CONCLUSIONS

Implantation of tissue-engineered cartilage-like tissue for the cartilage defects of the knee was effective in short- to midterm post-operatively. This procedure can be proposed as one option for repairing full-thickness cartilage defect of the knee.

LEVEL OF EVIDENCE

IV.

Fibrin glue improves osteochondral scaffold fixation: study on the human cadaveric knee exposed to continuous passive motion

OBJECTIVE

To evaluate stability and integrity of bi-layer and three-layer collagen-hydroxyapatite (C-HA) osteochondral scaffolds in a human cadaveric knee exposed to continuous passive motion (CPM) with and without loading and the role of added fibrin glue to improve the press-fit fixation of C-HA scaffolds.

DESIGN

Osteochondral lesions (2.0 × 1.5 cm) were chiseled out on both condyles and trochlea in eight human cadaveric knees. A total of 24 bi-layer (5 mm, four in each condyle) or three-layer C-HA scaffolds (8 mm, eight in the trochlea, four in each condyle) were first press-fit implanted and underwent testing with CPM, 90 cycles, 0°-90°. The second set of 24 scaffolds was implanted in cleaned lesions with the addition of fibrin glue. Two knees with fibrin glue fixation were additionally exposed to 15 kg loading, with 30 cycles of CPM, 0°-30°. Then, the knees were reopened and the scaffolds were evaluated using semi-quantitative Drobnic and modified Bekkers scores.

RESULTS

All but two scaffolds remained in the lesions site throughout CPM. Two implants failed: both were bi-layer osteochondral scaffolds, press-fit implanted at the lateral femoral condyle (LFC). A statistically significant difference was obtained between press-fit and fibrin glue implants with both Drobnic (2.9 ± 0.7 vs 4.3 ± 0.1, P < 0.0005) and Bekkers (3.3 ± 1.0 vs 5.0 ± 0.1, P < 0.0005) scores. Additional knee loading did not affect fibrin glue scaffold fixation or integrity.

CONCLUSION

This cadaveric study showed fibrin glue notably improved bi-layer or three-layer C-HA scaffold press-fit fixation regardless of lesion location. It is therefore recommended that fibrin glue be used during surgery to improve early post-operative C-HA scaffold stability and integrity.

Current state and use of biological adhesives in orthopedic surgery

Bone and tissue adhesives are common and beneficial supplements to standard methods of musculoskeletal tissue suture repair. Knowledge and development of biologically derived or inspired adhesives useful in orthopedic surgery are rapidly advancing. Recent literature demonstrates the increased adjunct or primary use of biological adhesives in the repair of musculoskeletal soft tissues, chondral fractures, and osteochondral fractures. Adhesives offer more benefits and enhancements to tissue healing than current fixation methods afford, including improved biocompatibility, resorbability, and non-immunogenicity. Further investigation is required to determine the extent of the role that these bioadhesives can play in orthopedic surgery. The largest group of biologically derived adhesives and sealants is fibrin sealants, which include first- and second-generation commercially available fibrin sealants, autologous fibrin sealants, and variants. Other groups include gelatin-resorcin aldehydes, protein-aldehyde systems, collagen-based adhesives, polysaccharide- based adhesives, mussel adhesive proteins, and various biologically inspired or biomimetic glues. Potential uses include applications in orthopedic-related blood conservation, arthroplasty, articular cartilage disorders, sports medicine, spine surgery, trauma, and tumors. The development of an adhesive with universal application is likely unfeasible, given the unique characteristics of various musculoskeletal tissues. However, the literature demonstrates the overall underuse of adhesives and indicates the rising probability of the development of a successful variety of bioadhesives for use in orthopedic surgery. As a result of reading this article, physicians should be able to: 1. Describe the difference between adhesives and sealants. 2. Recognize fibrin adhesives commonly used in practice today and identify other biological adhesives with rising potential. 3. Analyze how fibrin sealants work relative to fibrin and fibrinogen. 4. Identify anatomical areas and techniques in which fibrin sealants are used.

Autologous collagen-induced chondrogenesis: single-stage arthroscopic cartilage repair technique

Autologous collagen-induced chondrogenesis is a novel, single-staged arthroscopic cartilage repair technique using microdrilling and atelocollagen or fibrin gel application under carbon dioxide insufflation. Atelocollagen is a highly purified type I collagen obtained following the treatment of skin dermis with pepsin and telopeptide removal, making it nonimmunogenic. In this procedure, atelocollagen mixed with fibrinogen and thrombin in a 2-way syringe can maintain the shape of the articular surface approximately 5 minutes after application due to the reaction between the thrombin and fibrinogen. Carbon dioxide insufflation facilitates the application of the gel under dry conditions. Ten patients (mean age, 38 years) with symptomatic chondral defects in the knee who were treated arthroscopically with microdrilling and atelocollagen application were retrospectively analyzed. All defects were International Cartilage Repair Society grade III or IV and were 2 to 8 cm(2) in size intraoperatively. For the clinical assessment, Lysholm score was assessed preoperatively and at 2-year follow-up. All patients underwent morphological magnetic resonance imaging at 1.5-Tesla at 1-year follow-up. Mean Magnetic Resonance Imaging Observation of Cartilage Repair Tissue score at 1-year follow-up was 70.4 ± 20.2 (range, 15-95). The Magnetic Resonance Imaging Observation of Cartilage Repair Tissue score for patellar lesions was similar to that of lesions in other locations: 73.3 ± 11.7 vs 68.1 ± 25.5, respectively. This technique had encouraging clinical results at 2-year follow-up. Morphological magnetic resonance imaging shows good cartilage defect filling, and the biochemical magnetic resonance imaging suggests hyaline-like repair tissue.

Scaffolds for cartilage repair of the ankle joint: The impact on surgical practice

BACKGROUND

Ideal management of osteochondral lesions in the ankle joint is still theme of debate. Scaffold-based repair is emerging as a new approach for regenerative treatment.

METHODS

Articles published in PubMed from 2000 to January 2012 addressing cartilage scaffold-based treatment were identified, including levels I-IV evidence clinical trials with measures of functional, clinical or imaging outcome.

RESULTS

The analysis showed a progressively increasing number of articles from 2000. The number of selected papers was 19:15 focusing on two-step and 4 on one-step procedures; no randomized studies, 3 comparative studies, 11 case series and 5 case reports were identified.

CONCLUSIONS

Regenerative surgical approach with scaffold-based procedures is emerging as a potential therapeutic option for the treatment of chondral lesions of the ankle. One step treatments simplify the procedure and the results reported are very close to the previous techniques. However, well-designed studies are lacking, and randomized long-term trials are necessary to confirm the potential of these techniques.

LEVEL OF EVIDENCE

Review - IV.

Matrix assisted autologous chondrocyte transplantation for cartilage treatment: A systematic review

OBJECTIVES

Matrix-assisted autologous chondrocyte transplantation (MACT) has been developed and applied in the clinical practice in the last decade to overcome most of the disadvantages of the first generation procedures. The purpose of this systematic review is to document and analyse the available literature on the results of MACT in the treatment of chondral and osteochondral lesions of the knee.

METHODS

ALL STUDIES PUBLISHED IN ENGLISH ADDRESSING MACT PROCEDURES WERE IDENTIFIED, INCLUDING THOSE THAT FULFILLED THE FOLLOWING CRITERIA: 1) level I-IV evidence, 2) measures of functional or clinical outcome, 3) outcome related to cartilage lesions of the knee cartilage.

RESULTS

The literature analysis showed a progressively increasing number of articles per year. A total of 51 articles were selected: three randomised studies, ten comparative studies, 33 case series and five case reports. Several scaffolds have been developed and studied, with good results reported at short to medium follow-up.

CONCLUSIONS

MACT procedures are a therapeutic option for the treatment of chondral lesions that can offer a positive outcome over time for specific patient categories, but high-level studies are lacking. Systematic long-term evaluation of these techniques and randomised controlled trials are necessary to confirm the potential of this treatment approach, especially when comparing against less ambitious traditional treatments.

Scaffold-based repair for cartilage healing: a systematic review and technical note

PURPOSE

The aim of this systematic review was to address the treatment of chondral and osteochondral knee lesions through the use of scaffolds, by showing surgical options and results of this scaffold-based repair approach for the healing of the articular surface.

METHODS

All studies published in English addressing cartilage scaffold-based treatment were identified, including those that fulfilled the following criteria: (1) Levels I to IV evidence addressing the outlined areas of interest, (2) measures of functional or clinical outcome, (3) knee cartilage lesions, and (4) minimum of 2 years of follow-up.

RESULTS

The analysis showed a progressively increasing number of articles per year from 1995 to February 2012. The number of selected articles was 51, with 40 focusing on 2-step procedures and 11 focusing on 1-step procedures. The evaluation of evidence level showed 3 randomized studies, 10 comparative studies, 33 case series, and 5 case reports.

CONCLUSIONS

Regenerative scaffold-based procedures are emerging as a therapeutic option for the treatment of chondral lesions, but well-designed studies are lacking. Systematic long-term evaluation of these techniques and randomized studies are necessary to confirm the potential of this treatment approach, especially compared with the available traditional treatments. Different 1-step scaffold-based strategies are emerging to simplify the procedure and reduce costs.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I to IV studies.

The use of fibrin matrix-mixed gel-type autologous chondrocyte implantation in the treatment for osteochondral lesions of the talus

PURPOSE

This study assessed the clinical results and second-look arthroscopy after fibrin matrix-mixed gel-type autologous chondrocyte implantation to treat osteochondral lesions of the talus.

METHODS

Chondrocytes were harvested from the cuboid surface of the calcaneus in 38 patients and cultured, and gel-type autologous chondrocyte implantation was performed with or without medial malleolar osteotomy. Preoperative American orthopedic foot and ankle society ankle-hind foot scores, visual analogue score, Hannover scoring system and subjective satisfaction were investigated, and the comparison of arthroscopic results (36/38, 94.7 %) and MRI investigation of chondral recovery was performed. Direct tenderness and relationship to the active daily life of the donor site was evaluated.

RESULTS

The preoperative mean ankle-hind foot scores (71 ± 14) and Hannover scoring system (65 ± 10) had increased to 91 ± 12 and 93 ± 14, respectively, at 24-month follow-up (p < 0.0001), and the preoperative visual analogue score of 58 mm had decreased to 21 mm (p < 0.0001). Regarding subjective satisfaction, 34 cases (89.5 %) reported excellent, good or fair. Chondral regeneration was analysed by second-look arthroscopy and MRI. Complications included one non-union and two delayed-unions of the osteotomy sites, and 9 ankles (9/31, 29.0 %) sustained damaged medial malleolar cartilage due to osteotomy. Marked symptoms at the biopsy site did not adversely affect the patient's active daily life.

CONCLUSIONS

Fibrin matrix-mixed gel-type autologous chondrocyte implantation using the cuboid surface of the calcaneus as a donor can be used for treating osteochondral lesions of the talus.

Supporting Biomaterials for Articular Cartilage Repair

Orthopedic surgeons and researchers worldwide are continuously faced with the challenge of regenerating articular cartilage defects. However, until now, it has not been possible to completely mimic the biological and biochemical properties of articular cartilage using current research and development approaches. In this review, biomaterials previously used for articular cartilage repair research are addressed. Furthermore, a brief discussion of the state of the art of current cell printing procedures mimicking native cartilage is offered in light of their use as future alternatives for cartilage tissue engineering. Inkjet cell printing, controlled deposition cell printing tools, and laser cell printing are cutting-edge techniques in this context. The development of mimetic hydrogels with specific biological properties relevant to articular cartilage native tissue will support the development of improved, functional, and novel engineered tissue for clinical application.

Mesenchymal stem cell sheet encapsulated cartilage debris provides great potential for cartilage defects repair in osteoarthritis

The restoration of the degenerated articular cartilage in patients with osteoarthritis (OA) is still a challenge for researchers and clinicians. Drug interventions and surgical treatments have been widely attempted for cartilage regeneration in OA. However, the results were largely unsatisfactory. Autologous chondrocyte implantation (ACI) or matrix-induced autologous chondrocyte implantation (MACI) offers potential for the regeneration of cartilage over the long-term. However, due to the limitations and disadvantages of ACI, alternative therapies for cartilage regeneration are in need. The availability of large quantities of mesenchymal stem cells (MSCs) and the multilineage differentiation, especially their chondrogenic differentiation property, have made MSCs the most promising cell source for cartilage regeneration. In addition, MSCs have been shown the ability to undergo site-specific differentiation. MSCs can be obtained as MSC sheets using the temperature-responsive culture dish method. The MSC sheet can provide amounts of cells and extracellular matrix, which might provide the continuity between the implant and host cartilage, thus improving integrative cartilage repair. Moreover, OA is associated with progressive and often severe inflammation. MSCs not only have the ability to contribute structurally to tissue repair, but also possess potent immunomodulatory and anti-inflammatory effects. Taken together, these properties make MSC sheet promising candidate for cartilage repair in OA. We hypothesize that MSC sheet encapsulated cartilage debris can efficiently promote cartilage repair in OA patients. Chondrocytes can be obtained and cultured from small cartilage debris in vitro. Therefore, the chondrocytes may grow from the debris in cartilage defect and improve cartilage regeneration. MSC sheet provide amounts of cells, ECM and protein for cartilage regeneration and integration, and may play some roles of periosteum. The operation of MSC sheet encapsulated cartilage debris for cartilage repair is simple and practical. Moreover, the cell sheet/cartilage debris constructs can be easily shaped based on the size and shape of cartilage defects. The new method might have great potential in treating cartilage defects clinically, especially for OA patients.

Periosteal Transplantation Combined with the Autologous Matrix-Induced Chondrogenesis (AMIC) Technique in Isolated Patellofemoral Osteoarthritis: A Case Report

OBJECTIVE

Isolated cases of osteoarthritis of the knee represent a major clinical problem. A particular challenge is a case in which both articular surfaces are affected. Such is the case with the isolated form of patellofemoral osteoarthritis. Studies that describe methods for treating such conditions are few, and the results are not too promising.

METHODS

In this article, we present one such case of isolated patellofemoral osteoarthritis in which we used a new approach combining periosteal transplantation on one side and the autologous matrix-induced chondrogenesis (AMIC) technique on the other side.

RESULTS

The patient has improved, measured by the Knee injury and Osteoarthritis Outcome Score (KOOS) from 48 preoperatively to 77 at 1 year postoperatively (mean improvement) and measured by the Lysholm score from 45 preoperatively to 90 at 1 year postoperatively.

CONCLUSION

This original approach has shown promising results in this patient and could be tested in a larger group of patients with the same type of osteoarthritis in order to estimate its real clinical value.

Surgical treatment for early osteoarthritis. Part I: cartilage repair procedures

Young patients with early osteoarthritis (OA) represent a challenging population due to a combination of high functional demands and limited treatment options. Conservative measures such as injection and physical therapy can provide short-term pain relief but are only palliative in nature. Joint replacement, a successful procedure in the older population, is controversial in younger patients, who are less satisfied and experience higher failure rates. Therefore, while traditionally not indicated for the treatment of OA, cartilage repair has become a focus of increased interest due to its potential to provide pain relief and alter the progression of degenerative disease, with the hope of delaying or obviating the need for joint replacement. This review of cartilage repair techniques will discuss currently available procedures, specifically pertaining to experiences in the setting of early OA. Level of evidence IV.

Physiological cartilage tissue engineering effect of oxygen and biomechanics

In vitro engineering of cartilaginous tissues has been studied for many years, and tissue-engineered constructs are sought to be used clinically for treating articular cartilage defects. Even though there is a plethora of studies and data available, no breakthroughs have been achieved yet that allow for implanting in vivo cultured articular cartilaginous tissues in patients. A review of contributions to cartilage tissue engineering over the past decades emphasizes that most of the studies were performed under environmental conditions neglecting the physiological situation. This is specifically pronounced in the use of bioreactor systems which neither allow for application of near physiomechanical stimulations nor for controlling a hypoxic environment as it is experienced in synovial joints. It is suspected that the negligence of these important parameters has slowed down progress and prevented major breakthroughs in the field. This review focuses on the main aspects of cartilage tissue engineering with emphasis on the relation and understanding of employing physiological conditions.

Treatment of severe osteochondral defects of the knee by combined autologous bone grafting and autologous chondrocyte implantation using fibrin gel

PURPOSE

Severe symptomatic and unstable osteochondral defects of the knee are difficult to treat. A variety of surgical techniques have been developed. However, the optimal surgical technique is still controversial. We present a novel technique in which autologous bone grafting is combined with gel-type autologous chondrocyte implantation (GACI).

METHODS

Isolated severe osteochondral defects of the medial or lateral femoral condyle were treated by a two-step procedure. Firstly, chondrocytes were harvested during arthroscopy and cultured for 6 weeks. Secondly, a full thickness corticospongious autologuos bone graft, harvested from the medial or lateral femur condyle, is impacted in the defect and covered by GACI. The fibrin gel fills up to the exact shape of the chondral lesion and polymerizes within 3 min after application.

RESULTS

From 2009 to 2011, 9 patients, median age 35 years (range 23–47), were treated by the combined autologous bone grafting and GACI technique. Median defect size was 7.1 cm2 (range 2.5–12.0), and median depth of the lesion was 0.9 cm (range 0.8–1.2). Median follow-up was 9 months (range 6–12 months). Six patients were available for 12-month follow-up. The mean IKDC score showed a 6-month improvement from 35 (SD ± 16) to 51 (SD ± 18) (n = 9; p = 0.01), and a 1-year improvement from 35 (SD ± 16) to 57 (SD ± 20) (n = 6; p = 0.03). The mean KOOS improved from 44 (SD ± 16) to 62 (SD ± 19) (n = 9; p = 0.07) at 6-month follow-up and from 44 (SD ± 16) to 65 (SD ± 24) (n = 6; p = 0.1) at 12-month follow-up. There was one failure that needed conversion to a unicompartmental knee arthroplasty.

CONCLUSION

Combined autologous bone grafting and GACI may offer an alternative surgical option for severe and unstable osteochondral defects of the knee.