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Articular cartilage defects heal poorly. Autologous Matrix-Induced Chondrogenesis (AMIC) is an innovative treatment for localized full-thickness cartilage defects combining the well-known microfracturing with collagen scaffold and fibrin glue. The purpose of this prospective study was to evaluate the medium-term results of this enhanced microfracture technique for the treatment of chondral lesions of the knee. Thirty-two chondral lesions in 27 patients were treated with AMIC. Within the context of clinical follow-up, these patients were evaluated for up to 5 years after the intervention. Five different scores (Meyer score, Tegner score, Lysholm score, ICRS score, Cincinnati score) as well as radiographs were used for outcome analysis. Articular resurfacing was assessed by magnetic resonance imaging (MRI). The average age of patients (11 females, 16 males; mean body mass index 26, range 20-32) was 37 years (range 16-50 years). The mean defect size of the chondral lesions was 4.2 cm(2) (range 1.3-8.8 cm(2)). All defects were classified as grade IV according to the Outerbridge classification. The follow-up period was between 24 and 62 months with a mean of 37 months. Twenty out of 23 individuals (87%) questioned were subjectively highly satisfied with the results after surgery. Significant improvement (P < 0.05) of all scores was observed as early as 12 months after AMIC, and further increased values were notable up to 24 months postoperatively. MRI analysis showed moderate to complete filling with a normal to incidentally hyperintense signal in most cases. Results did not show a clinical impact of patient's age at the time of operation, body mass index and number of previous operations (n.s.). In contrast, males showed significant higher values in the ICRS score compared to their female counterparts. AMIC is an effective and safe method of treating symptomatic full-thickness chondral defects of the knee in appropriately selected cases. However, further studies with long-term follow-up are needed to determine whether the grafted area will maintain structural and functional integrity over time.

Purpose Articular resurfacing by treatment of chondral defects may include chondral abrasion, autologous chondrocyte Implantation (ACI), matrix‐induced chondrocyte transplantation (MACT) or osteochondral autologous transplantation (OATS). This technical note describes the method of autologous matrix‐induced chondrogenesis (AMIC), a one‐step procedure combining subchondral microfracture with the fixation of a collagen I/III membrane with fibrin glue or sutures. Methods This is a technical note on the AMIC procedure and its further development. Results and conclusion This method is applied primarily in chondral or osteochondral lesions of the knee. Indications and contraindications are provided; the technique is described. The further development of AMIC is described with an increased focus on the subchondral zone and the complex of cartilage and bone, the osteochondral unit, which receives increased attention in cartilage research. Level of evidence IV.

IntroductionAutologous Matrix-Induced Chondrogenesis (AMIC) is an innovative treatment for localized full-thickness cartilage defects combining the well-known microfracturing with collagen I/III scaffold. The purpose of this analysis was to evaluate the medium-term results of this enhanced microfracture technique for the treatment of chondral lesions of the knee.Methods and materialsPatients treated with AMIC (Chondro-Gide®, Geistlich Pharma, Switzerland) were followed using the AMIC Registry, an internet-based tool to longitudinally track changes in function and symptoms by the Lysholm score and VAS.ResultsA series of 57 patients was enrolled. The average age of patients (19 females, 38 males) was 37.3 years (range 17–61 years). The mean defect size of the chondral lesions was 3.4 cm2 (range 1.0–12.0 cm2). All defects were classified as grade III (n = 20) or IV (n = 37) according to the Outerbridge classification. Defects were localized at the medial (n = 32) or lateral (n = 6) condyle, at the trochlea (n = 4) and at the patella (n = 15). The follow-up period was 2 years. The majority of patients were satisfied with the postoperative outcome, reporting a significant decrease of pain (mean VAS preop = 7.0; 1 year postop = 2.7; 2 years postop = 2.0). Significant improvement of the mean Lysholm score was observed as early as 1 year after AMIC and further increased values were noted up to 2 years postoperatively (preop. 50.1, 1 year postop. 79.9, 2 year postop. 85.2).ConclusionsAMIC is an effective and safe method of treating symptomatic chondral defects of the knee. However, further studies with long-term follow-up are needed to determine if the grafted area will maintain structural and functional integrity over time.Level of evidencePrognostic study, Level IV.

The first steps of stroma generation are of pivotal importance for carcinogenesis because at this stage are initiated both angiogenesis, the prerequisite for continuous tumour growth, and the proliferation of stromal fibroblasts. These developments contribute to the onset of tumour invasion by secreting several matrix-degrading proteases. Both angiogenesis and the production of proteases are tightly controlled at several levels; of significant importance is transcription. The Ets-1 transcription factor transactivates several genes encoding matrix-degrading proteases and is thought to be involved in both tumour vascularization and invasion. This study therefore investigated, by in situ hybridization and immunohistochemistry, the expression of Ets-1 and of two of its target genes, encoding matrix metalloproteinase (MMP) 1 and MMP 9, in order to demonstrate a topographical in vivo correlation between the expression of these three genes during breast cancer formation. All three genes were first expressed within both endothelial cells and stromal fibroblasts during the onset of stroma generation around intraductal and intralobular in situ carcinomas and they were significantly up-regulated in the stroma of invasive ductal and lobular cancers. The results of this study further support the suggested in vivo role of Ets-1 for both angiogenesis and tumour invasion, via matrix-degrading proteases which are already expressed during the early stages of breast carcinogenesis.