Cartilage Regeneration
Cartilage is a tough but flexible tissue that is the main type of connective tissue in the body. Around 65–80% of cartilage is water, although that decreases in older people, and the rest is a gel-like substance called the ‘matrix’ that gives it its form and function.The matrix is highly organised and consists of several types of specialist proteins, called: Collagens, Proteoglycans and Non-collagenous proteins. The proteoglycan and non-collagenous proteins bind, or stick to the collagen, which forms a mesh. Water is attracted to the mesh by negatively charged proteins. Together, these give the matrix its consistency.
There are three main types of cartilage:
- Hyaline
- Elastic
- Fibrous
All have different properties that correspond to their specific functions in the body and make it the most appropriate type of cartilage at that particular site.
- Hyaline, or articular cartilage, is found in the joints, septum of the nose (which separates the nostrils), and the trachea (air tube).
- Elastic cartilage, which has elastic fibres that make the cartilage more flexible, is found in the ear, part of the nose and the trachea.
- Fibrous cartilage occurs in special cartilage pads called menisci that help to disperse body weight and reduce friction, such as in the knee.
In the joints, hyaline cartilage forms a very low friction, 2-4 mm thick layer that coats the bony surfaces. This allows the bones of the joint to glide over one another during movement and, ideally, last a lifetime. It also serves as a cushion and shock absorber in the joint. The articular cartilage matrix is produced and maintained by a group of cartilage cells inside the matrix known as ‘chondrocytes’. These come from a mesh of connective tissue in the embryo called the ‘mesenchyme’.
The volume of cells in the cartilage is small, making up about 1%–2% of the tissue volume in adults. Cartilage contains no blood vessels (avascular), no nerves (aneural) and no lymphatic system (alymphatic). This makes the cartilage with very low potential to heal by itself. So whenever cartilage damage occurs the healing response is vey low except in very young individuals. Therefore cartilage injuries and conditions need active intervention to be treated and to heal.
Can I be treated without Surgery?
The short answer is yes – it is possible for you to be treated without surgery. However, the appropriateness of non-operative management will be based on the nature of joint complaint. For example, if you have sustained an acute injury to your knee that has resulted in a loose piece of articular cartilage that is causing mechanical symptoms, then you may not be a candidate for non-operative management. But for the majority of cartilage and joint conditions your healthcare provider will generally have you undergo a trial of non-operative management.
There are a variety of different non-operative interventions that can be used such as life-style modifications (weight loss and no high impact activities), physiotherapy, braces, viscosupplementation, neutraceuticals and platelet-rich plasma to name a few of the options. However, a consultation with your physician is required to identify the exact nature of your cartilage or joint problem and this will allow him/her to formulate an individualized non-operative treatment strategy for your condition. The decision to proceed with surgery is multifactorial and some of the key issues to be considered are the character (size, location and chronicity) of the defect, prior interventions, the presence of any other concomitant injuries and your overall health.
After careful consultation with your surgeon about the nature of your articular cartilage injury and if appropriate for your injury a trial of non-operative, then the decision to proceed with surgery is generally made. The nature of the surgical procedure will be tailored to your injury and may consist of an arthroscopic surgery, an open procedure, or a combination of the two different procedures.
Cartilage Repair Techniques
The focus here is on articular cartilage repair treatment, which means the restoration of damaged hyaline cartilage in the joints. Cartilage repair and regeneration is a treatment for joints that have damaged cartilage but are otherwise healthy. The treatment is recommended for patients with cartilage damage or deterioration caused by:
- Injury or trauma, including sports injuries
- Repetitive use of the joint
- Congenital abnormalities – abnormalities a person is born with – that affect normal joint structure
- Hormonal disorders that affect bone and joint development, such as osteochondritis dissecans (OCD)
There are several types of procedures for cartilage repair and regeneration that are designed to heal the cartilage by filling the cartilage defect (pothole) with repair tissue.
The choice of procedure depends on the size and location of the defect. Larger defects are typically treated with autologous chondrocyte transplantation or osteochondral allograft transplantation, both of which require open incisions. Smaller defects in specific locations can be treated with marrow-stimulating techniques, autologous chondrocyte implantation (ACI), or osteochondral autograft transfer. The various modalities of cartilage repair are the following . You need to sit and discuss with your treating physician to select the best available treatment method based upon multiple factors .
- Debridement and micerfracture
- Radiofrequency
- Mosiacplasty
- Autologous Chondrocyte Implantation (ACI)
- Autologous Matrix-induced Chondrogenesis (AMIC)
- Allograft
- Osteotomy
- New Scafollds and Cells
- Growth Factors
- The Future of Cartilage Repair
- Joint Resurfacing and Joint Replacement