Tissue engineering of different cartilage types: a review of different approaches and recent advances

Cartilage is a connective tissue that serves as a structural support for maintaining the shape for specific appendices (nose, ear) and also helps for shock absorption when present in joints. Different types of cartilage coexist in the body: hyaline, elastic and fibrocartilage. Due to their different embryologic origin, they produce distinct extracellular matrix and therefore have specific functions according to their location. Cartilage is frequently subjected to many different lesions. Those include traumatic, metabolic and congenital forms, concerning all regions where this tissue is present: joints, head and neck area, intervertebral disks, etc. Increasing number of cancers also affects cartilage; especially in ear, nose and trachea. Unfortunately, this tissue has a poor regeneration ability. Few therapeutic options exist for cartilaginous lesions and most of them concern articular cartilage. They include micro fracture, autologous chondrocytes implantation, mosaicplasty, allograft and prosthesis. Ear and trachea are also targeted for reconstruction with lesser extent. Therefore, cartilage engineering highly addresses increasing number of pathologies associated to this tissue. In the last two decades, several trials were investigated using both progenitor cells and scaffolds. Even bone marrow derived stem cells were widely used and served as gold standard. Many progenitors from different areas are investigated for their capacity of chondrogenesis. On the other hand, biomaterials, natural and synthetic, are used to induce a 3D environment that allows proper growth and differentiation toward cartilage formation. Their characteristics depend on the location of the expected graft where porosity, biodegradability, ability to support strength and large scale use are the key points. Favorable environments are also needed to achieve appropriate chondrogenesis, including biochemical or mechanical stimuli and low oxygen tension. Bioprinting showed also encouraging outcomes in cartilage reconstruction with the investigation of several scaffolds.

Patellofemoral Cartilage Restoration: Indications, Techniques, and Outcomes of Autologous Chondrocytes Implantation, Matrix-Induced Chondrocyte Implantation, and Particulated Juvenile Allograft Cartilage

Focal chondral defects are common in the patellofemoral (PF) joint and can significantly impair the quality of life. The autologous chondrocytes implantation (ACI) technique has evolved over the past 20 years: the first-generation technique involves the use of a periosteal patch, the second-generation technique (collagen-cover) uses a type I/III collagen membrane, and the newest third-generation technique seeds and cultivates the collagen membrane with chondrocytes prior to implantation and is referred to as matrix-induced autologous chondrocyte implantation. Particulated juvenile allograft cartilage (PJAC) (DeNovo NT) is minced cartilage allograft from juvenile donors. A thorough physical exam is important, especially for issues affecting the PF joint, to isolate the location and source of pain, and to identify associated pathologies. Imaging studies allow further characterization of the lesions and identification of associated pathologies and alignment. Conservative management should be exhausted before proceeding with surgical treatment. Steps of surgical treatment are diagnostic arthroscopy and biopsy, chondrocytes culture and chondrocyte implantation for the three generations of ACI, and diagnostic arthroscopy and implantation for PJAC. The techniques and their outcomes will be discussed in this article.

Three-Dimensional Matrix-Induced Autologous Chondrocytes Implantation for Osteochondral Lesions of the Talus: Midterm Results

Introduction. We evaluate the midterm results of thirty patients who underwent autologous chondrocytes implantation for talus osteochondral lesions treatment.Materials and Methods. From 2002 to 2009, 30 ankles with a mean lesion size of 2,36 cm2were treated. We evaluated patients using American Orthopaedic Foot and Ankle Surgery and Coughlin score, Van Dijk scale, recovering time, and Musculoskeletal Outcomes Data Evaluation and Management System.Results. The mean AOFAS score varied from 36.9 to 83.9 at follow-up. Average of Van Dijk scale was 141.1. Coughlin score was excellent/good in 24 patients. MOCART score varied from 6.3 to 3.8.Discussion. This matrix is easy to handle conformable to the lesion and apply by arthroscopy. No correlation between MRI imaging and clinical results is found.Conclusions. Our results, compared with those reported in literature with other surgical procedures, show no superiority evidence for our technique compared to the others regarding the size of the lesions.