Autologous matrix-induced chondrogenesis (AMIC) is a treatment for

articular cartilage damage 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 i ...

. It combines

microfracture surgery Fracture mechanics is the field of mechanics concerned with the study of the propagation of cracks in materials. It uses methods of analytical solid mechanics to calculate the driving force on a crack and those of experimental solid mechanics t ...

with the application of a bi-layer collagen I/III membrane. There is tentative short to medium term benefits as of 2017. The initialism AMIC, often used as a

genericized trademark A generic trademark, also known as a genericized trademark or proprietary eponym, is a trademark or brand name that, because of its popularity or significance, has become the generic term for, or synonymous with, a general class of products or ...

, is a registered trademark of Ed. Geistlich Söhne AG, protected by German Registration No. 30255356 and international Registration No. 840373. The procedure described below relates specifically to the use of a collagen membrane, but recent advances now allow the use, using the same surgical procedure of non woven bio degradable materials that were initially developed for cell culturing of chondrocytes to be employed. These purely synthetic materials ( contain no animal derived products) are often further enhanced by impregnation of the material with high concentrations of Hyaluronic acid, which has been shown to be required to stimulate the differentiation of stem cells migrating from the bone marrow into chondrocytes (the true cartilage cell) and the resultant synthesis of type 2 collagen, the same native collagen found in the undamaged cartilage tissue. These enhanced synthetic biodegradable materials have been used to treat lesions in the knee, ankle, hip and great toe.

Procedure

Autologous Matrix Induced Chondrogenesis (AMIC) surgery is a single step procedure. After arthroscopic evaluation of the cartilage damage and decision for an AMIC procedure a mini

arthrotomy An arthrotomy is the creation of an opening in a joint that may be used in drainage. See also * List of surgeries by type Many surgical procedure names can be broken into parts to indicate the meaning. For example, in gastrectomy, "ectomy" is ...

is performed. An all-arthroscopic AMIC procedure for repair of cartilage defects of the knee is also possible. First the cartilage defect is exposed and cleaned whereby all unstable degenerated cartilage, including the calcified cartilage layer, are carefully removed. An imprint of the defect is then taken using a

sterile Sterile or sterility may refer to: *Asepsis, a state of being free from biological contaminants * Sterile (archaeology), a sediment deposit which contains no evidence of human activity *Sterilization (microbiology), any process that eliminates or ...

moldable material (e.g.

aluminium foil Aluminium foil (or aluminum foil in North American English; often informally called tin foil) is aluminium prepared in thin metal leaves with a thickness less than ; thinner gauges down to are also commonly used. Standard household foil is typ ...

) and transferred to the collagen membrane which is cut to shape. The surgeon then creates tiny holes/fractures in the subchondral bone plate ( microfracturing) with a special awl.

Blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...

and

bone marrow Bone marrow is a semi-solid tissue found within the spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or haematopoiesis). It is composed of hematopoietic ce ...

(containing

stem cell In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can differentiate into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type o ...

s) are released forming a

blood clot A thrombus (plural thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of c ...

which contains cartilage forming elements. The correctly sized collagen membrane is added to the microfractured area either by

fibrin glue Fibrin glue (also called fibrin sealant) is a surgical formulation used to create a fibrin clot for hemostasis, cartilage repair surgeries or wound healing. It contains separately packaged human fibrinogen and human thrombin. Medical uses This g ...

(

autologous Autotransplantation is the transplantation of organs, tissues, or even particular proteins from one part of the body to another in the same person ('' auto-'' meaning "self" in Greek). The autologous tissue (also called autogenous, autogene ...

or commercially available) or

suturing A surgical suture, also known as a stitch or stitches, is a medical device used to hold body tissues together and approximate wound edges after an injury or surgery. Application generally involves using a needle with an attached length of threa ...

. Through flexion of the joint, the stable positioning of the membrane is verified and the wound is closed. An essential requirement for satisfying outcome of the AMIC surgery is the compliance to a strict

physical therapy Physical therapy (PT), also known as physiotherapy, is one of the allied health professions. It is provided by physical therapists who promote, maintain, or restore health through physical examination, diagnosis, management, prognosis, patient ...

program. Guidelines and recommendations exist, though they have to be adapted to the individual patients needs.

History

The AMIC procedure was first proposed by Behrens in 2003. it aims to extend the use of microfracture surgery to larger cartilage lesions > 2.5 cm2. Its clinical efficiency in autologous chondrocyte implantation (ACI), another cartilage repair technique for larger cartilage lesions, has been studied. In general various factors have been identified known to influence the result after cartilage repair regardless of the technique used. Amongst them are the species and age of the individual, the size and localization of the articular cartilage defect, the surgical technique, and the postoperative rehabilitation protocol. The latter has been found especially important for microfracture surgery and therefore for AMIC. The basic procedure of Microfracture surgery was developed by JR Steadman in the late 80’s and early 90’s. It is a well documented cartilage repair technique and first line treatment option for small cartilage lesions. AMIC evolved with the aim to improve some of the shortfalls of microfracture surgery as for instance variable repair cartilage volume and functional deterioration over time.

References

External links

{{DEFAULTSORT:Autologous Matrix Induced Chondrogenesis Orthopedic surgical procedures