Autologous matrix-induced chondrogenesis is a trade mark owned by Geistlich Pharma, and relates only to the use of their product. The term Autologous Matrix Induced Chondrogenesis is however used by surgeons to generally describe a procedure using a material to enhance the natural healing process that microfracture affords. 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 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 and the resultant synthesis of type 2 collagen - the same native collagen found in the undamaged cartilage tissue. These enhanced synthetic bio - degradable materials have been successfully used to treat lesions in the Knee, Ankle, Hip and Great toe. Studies following the progress of knee patients have shown significant and persistent recovery following treatment. articular cartilage damage. There is tentative short to medium term benefits of the material described below as of 2017. It combines microfracture surgery with the application of a bi-layer collagen I/III membrane.
Procedure
Autologous Matrix Induced Chondrogenesis surgery is a single step procedure. After arthroscopic evaluation of the cartilage damage and decision for an AMIC procedure a mini arthrotomy 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 moldable material and transferred to the collagen membrane which is cut to shape. The surgeon then creates tiny holes/fractures in the subchondral bone plate with a special. Blood and bone marrow are released forming a blood clot which contains cartilage forming elements. The correctly sized collagen membrane is added to the microfractured area either by fibrin glue or suturing. Through flexion of the joint, the stable positioning of the membrane is verified and the wound is closed. A critical phase and actually essential requirement for satisfying outcome of the AMIC surgery is the compliance to a strict physical therapy 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. Its clinical efficiency in autologous chondrocyte implantation, 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. Microfracture surgery was developed by Dr. Steadman in the late 1980s and early 1990s. 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.
