Cartilage is a resilient and smooth type of connective tissue. It is a semi-transparent and non-porous type of tissue. It is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck and the bronchial tubes, and the intervertebral discs. In other taxa, such as chondrichthyans, but also in cyclostomes, it may constitute a much greater proportion of the skeleton. It is not as hard and rigid as bone, but it is much stiffer and much less flexible than muscle. The matrix of cartilage is made up of glycosaminoglycans, proteoglycans, collagen fibers and, sometimes, elastin. It usually grows quicker than bone.
Chondropathy refers to a disease of the cartilage. It is frequently divided into 5 grades, with 0-2 defined as normal and 3-4 defined as diseased.
Osteochondritis dissecans is a joint disorder primarily of the subchondral bone in which cracks form in the articular cartilage and the underlying subchondral bone. OCD usually causes pain during and after sports. In later stages of the disorder there will be swelling of the affected joint which catches and locks during movement. Physical examination in the early stages does only show pain as symptom, in later stages there could be an effusion, tenderness, and a crackling sound with joint movement.
A meniscus transplant or meniscal transplant is a transplant of the meniscus of the knee, which separates the thigh bone (femur) from the lower leg bone (tibia). The worn or damaged meniscus is removed and is replaced with a new one from a donor. The meniscus to be transplanted is taken from a cadaver, and, as such, is known as an allograft. Meniscal transplantation is technically difficult, as it must be sized accurately for each person, positioned properly and secured to the tibial plateau. Its success also depends on donor compatibility, stability of the transplant, and long-term health of the underlying articular cartilage.
Chondrogenesis is the process by which cartilage is developed.
Articular cartilage, most notably that which is found in the knee joint, is generally characterized by very low friction, high wear resistance, and poor regenerative qualities. It is responsible for much of the compressive resistance and load bearing qualities of the knee joint and, without it, walking is painful to impossible. Osteoarthritis is a common condition of cartilage failure that can lead to limited range of motion, bone damage and invariably, pain. Due to a combination of acute stress and chronic fatigue, osteoarthritis directly manifests itself in a wearing away of the articular surface and, in extreme cases, bone can be exposed in the joint. Some additional examples of cartilage failure mechanisms include cellular matrix linkage rupture, chondrocyte protein synthesis inhibition, and chondrocyte apoptosis. There are several different repair options available for cartilage damage or failure.
Microfracture surgery is an articular cartilage repair surgical technique that works by creating tiny fractures in the underlying bone. This causes new cartilage to develop from a so-called super-clot.
Articular cartilage damage in the knee may be found on its own but it will more often be found in conjunction with injuries to ligaments and menisci. People with previous surgical interventions face more chances of articular cartilage damage due to altered mechanics of the joint. Articular cartilage damage may also be found in the shoulder causing pain, discomfort and limited movement. Cartilage structures and functions can be damaged. Such damage can result from a variety of causes, such as a bad fall or traumatic sport-accident, previous knee injuries or wear and tear over time. Immobilization for long periods can also result in cartilage damage.
Autologous chondrocyte implantation is a biomedical treatment that repairs damages in articular cartilage. ACI provides pain relief while at the same time slowing down the progression or considerably delaying partial or total joint replacement surgery. The goal of ACI is to allow people suffering from articular cartilage damage to return to their old lifestyle; regaining mobility, going back to work and even practicing sports again.
Mesenchymal stem cells (MSCs) are multipotent cells found in multiple human adult tissues, including bone marrow, synovial tissues, and adipose tissues. Since they are derived from the mesoderm, they have been shown to differentiate into bone, cartilage, muscle, and adipose tissue. MSCs from embryonic sources have shown promise scientifically while creating significant controversy. As a result, many researchers have focused on adult stem cells, or stem cells isolated from adult humans that can be transplanted into damaged tissue.
Kevin Robert Stone is an American physician, orthopedic surgeon, clinician, researcher, and company founder of The Stone Clinic and the Stone Research Foundation in San Francisco.
Autologous matrix-induced chondrogenesis (AMIC) is a treatment for articular cartilage damage. It combines microfracture surgery with the application of a bi-layer collagen I/III membrane. There is tentative short to medium term benefits as of 2017.
Cartilage repair techniques are the current focus of large amounts of research. Many different strategies have been proposed as solutions for cartilage defects. Surgical techniques currently being studied include:
Orthopedic surgery is the branch of surgery concerned with conditions involving the musculoskeletal system. Orthopedic surgeons use both surgical and nonsurgical means to treat musculoskeletal injuries, sports injuries, degenerative diseases, infections, bone tumours, and congenital limb deformities. Trauma surgery and traumatology is a sub-specialty dealing with the operative management of fractures, major trauma and the multiply-injured patient.
The treatment of equine lameness is a complex subject. Lameness in horses has a variety of causes, and treatment must be tailored to the type and degree of injury, as well as the financial capabilities of the owner. Treatment may be applied locally, systemically, or intralesionally, and the strategy for treatment may change as healing progresses. The end goal is to reduce the pain and inflammation associated with injury, to encourage the injured tissue to heal with normal structure and function, and to ultimately return the horse to the highest level of performance possible following recovery.
Autologous cultured chondrocytes on porcine collagen membrane (Maci) is a treatment to correct cartilage defects in the knee. It is used to treat symptomatic, full-thickness cartilage defects of the knee with or without bone involvement. Autologous cultured chondrocytes on porcine collagen membrane is an autologous cellularized scaffold product. This treatment is approved by the US Food and Drug Administration (FDA). It is only administered to adults. Healthy cartilage is removed from the person's own knees and a 'scaffold' is created on which the healthy tissue growths. This is an autologous matrix-induced chondrogenesis procedure which prevents tissue rejection complications since the transplanted cartilage comes from the same person.
Nasal chondrocytes (NC) are present in the hyaline cartilage of the nasal septum and in fact are the only cell type within the tissue. Similar to chondrocytes present in articular cartilage, NC express extracellular matrix proteins such as glycosaminoglycans and collagen.
Artificial cartilage is a synthetic material made of hydrogels or polymers that aims to mimic the functional properties of natural cartilage in the human body. Tissue engineering principles are used in order to create a non-degradable and biocompatible material that can replace cartilage. While creating a useful synthetic cartilage material, certain challenges need to be overcome. First, cartilage is an avascular structure in the body and therefore does not repair itself. This creates issues in regeneration of the tissue. Synthetic cartilage also needs to be stably attached to its underlying surface i.e. the bone. Lastly, in the case of creating synthetic cartilage to be used in joint spaces, high mechanical strength under compression needs to be an intrinsic property of the material.
Craniofacial regeneration refers to the biological process by which the skull and face regrow to heal an injury. This page covers birth defects and injuries related to the craniofacial region, the mechanisms behind the regeneration, the medical application of these processes, and the scientific research conducted on this specific regeneration. This regeneration is not to be confused with tooth regeneration. Craniofacial regrowth is broadly related to the mechanisms of general bone healing.
Spheroids of human autologous matrix-associated chondrocytes, sold under the brand name Spherox, is a medication used to repair defects to the cartilage in the knee in adults who are experiencing knee pain and problems moving the knee. It is used where the affected area is no larger than 10 cm2 (1.6 sq in).
