Articular cartilage lesions are a common pathology of the knee joint even in young patients resulting in pain and function loss. ith time). Given the limitations of MFx, efforts have focused on modifications and augmentation techniques for improving the quality of the repair tissue. Autologous, matrix-induced chondrogenesis (AMIC) is an enhanced MFx technique by covering the microfractured lesion site with a collagen I/III membrane in the knee (ChondroGide®, Geistlich Pharma AG).
In basic science, Kramer et al. showed in an in-vitro work that a membrane consisting of collagen can retain cartilage building cells, like, e.g., mesenchymal stem cells from bone marrow after microfracturing [1]. Dickhut et al. [2] demonstrated in another in-vitro study that a biphasic carrier made of collagen type I/III supports chondrogenesis of MSCs and further that in comparison to collagen-free-membrane the form stability of the repair tissue was enhanced.
In vivo, 1 long-term study in sheep showed that AMIC significantly enhanced the cartilaginous repair tissue volume (eg, defect fill) compared with microfracture alone [3].
Intial clincal studies that have investigated short-term and medium-term follow-up cohorts suggest that AMIC in cartilage repair is a safe and effective treatment option that improves patient outcome measures and pain [4, 5]. To assess extended effectiveness and reliability of the AMIC procedure as well as the durability of the repaired cartilage, long-term follow up is essential. Two studies provide longer term data following an AMIC procedure, in which significant clinical and functional improvement was maintained over the 7-year follow-up [6, 7]. The AMIC procedure can be either performed with an open surgical approach or arthroscopically [8].
Steinwachs et al. summarize the results of 12 studies including 375 patients in a recent meta-analysis. The authors conclude that the AMIC procedure significantly improved the clinical status and functional scoring versus preoperative values [9].
[1] Kramer J, Böhrnsen F, Lindner U, Behrens P, Schlenke P, Rohwedel J. In vivo matrix-guided human mesenchymal stem cells. Cell Mol Life Sci 2006; 63: 616-626 [PMID: 16482398 DOI: 10.1007/s00018-005-5527-z]
[2] Dickhut A, Gottwald E, Steck E, Heisel C, Richter W. Chondrogenesis of mesenchymal stem cells in gel-like biomaterials in vitro and in vivo. Front Biosci 2008; 13: 4517-4528 [PMID: 18508526 DOI: 10.2741/3020]
[3] Gille J, Kunow J, Boisch L, Behrens P, Bos I, Hoffmann C, Köller W, Russlies M, Kurz B. Cell-Laden and Cell-Free Matrix-Induced Chondrogenesis versus Microfracture for the Treatment of Articular Cartilage Defects: A Histological and Biomechanical Study in Sheep. Cartilage 2010; 1: 29-42 [DOI: 10.1177/1947603509358721]
[4] Gille J, Behrens P, Volpi P, et al. Outcome of Autologous Matrix Induced Chondrogenesis (AMIC) in cartilage knee surgery: data of the AMIC Registry. Arch Orthop Trauma Surg. 2013;133(1):87-93.
[5] Gille J, Schuseil E, Wimmer J, et al. Mid-term results of Autologous Matrix-Induced Chondrogenesis for treatment of focal cartilage defects in the knee. Knee Surg Sports Traumatol Arthrosc. 2010;18(11):1456-1464.
[6] Schiavone Panni A, Del Regno C, Mazzitelli G, et al. Good clinical results with autologous matrix-induced chondrogenesis (AMIC) technique in large knee chondral defects. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA. 2018;26(4):1130-1136.
[7] Gille J, Reiss E, Freitag M et al. AMIC for treatment of focal cartilage defects in the knee. Orthopaedic Journal of Sports Medicine. 2021; 66, 9(2) 2325967120981872
[8] Schagemann J, Behrens P, Paech A, et al. Mid-term outcome of arthroscopic AMIC for the treatment of articular cartilage defects in the knee joint is equivalent to mini-open procedures. Arch Orthop Trauma Surg. 2018;138(6):819-825.
[9] Steinwachs MR, Gille J, Volz M, et al. Systematic Review and Meta-Analysis of the Clinical Evidence on the Use of Autologous Matrix-Induced Chondrogenesis in the Knee. Cartilage. 2019:1947603519870846.