A non-weight-bearing part of the articular surface is used for harvest.
A non-weight-bearing part of the articular surface is used for harvest.
Technique of mACI
Damaged joint cartilage does not heal well on its own.
Procedures of cartilage repair have been developed to fill in deep defects with more viable cartilage material.
In the mACI procedure, the surgeon performs an arthroscopy to check the status of the joint cartilage and the defect, and to harvest bits of healthy cartilage from part of the lower femur where the cartilage is not really bearing weight. Living healthy cartilage cells (chondrocytes) are then extracted and cultivated in the laboratory, and treated for a few weeks so that they multiply on a membrane that acts as culture medium.
Then the patient is booked for a second surgical procedure, where the original defect is cleaned up and the new cell-filled membrane is secured into the hole, where it should grow and fill the space and build up its own matrix between the chondrocytes.
Peer-reviewed papersQuote from peer-reviewed paper:
"....Several critical factors may determine clinical outcomes and quality of repair tissue after MACI procedure in patients, including 1) successful chondrocyte culture and expansion, 2) technical proficiency of the surgeons...., 3) patient cooperation and compliance in all aspects of the preoperative and postoperative programs...., and 4) timely progression of weight-bearing and adjunct exercises and postoperative rehabilitation...."
Citation: Zhang Z, Zhong X, Ji H, Tang Z, Bai J, Yao M, Hou J, Zheng M, Wood DJ, Sun J, Zhou SF, Liu A. Matrix-induced autologous chondrocyte implantation for the treatment of chondral defects of the knees in Chinese patients. Drug Des Devel Ther. 2014 Dec 5;8:2439-48. doi: 10.2147/DDDT.S71356. PMID: 25525334; PMCID: PMC4266264.
Comparing mACI and ACI
ACI is an earlier cartilage repair procedure, and mACI was developed from it and is more sophisticated.
ACI is a two-stage procedure, where chondrocytes are cultured and then are injected into the defect behind a 'curtain' of connective tissue harvested from adjacent bone and which has been sutured over the defect to contain the new cells.
Quick linksComparing mACI and AMIC
A one-step procedure - AMIC - has also been developed -
- mACI (matrix-induced autologous chondrocyte implantation) is a two-step cartilage repair technique, where the expanded cells are seeded onto a membrane in the laboratory, and which is then implanted back into the patient.
- AMIC (autologous matrix-induced chondrogenesis) is a one-step procedure, where the defect is subjected to microfracture to release underlying stem cells, and a membrane is glued over the area using fibrin glue.
Quote from peer-reviewed paper:
"....a partially autologous fibrin glue may be manufactured by centrifuging a blood sample from the patient and mixing the yielded thrombin with allogenic fibrinogen...."
Citation: Benthien JP, Behrens P. Autologous Matrix-Induced Chondrogenesis (AMIC): Combining Microfracturing and a Collagen I/III Matrix for Articular Cartilage Resurfacing. Cartilage. 2010 Jan;1(1):65-8. doi: 10.1177/1947603509360044. PMID: 26069536; PMCID: PMC4440611.
Quote from peer-reviewed paper:
"AMIC may provide better outcomes than mACI for chondral defects of the knee."
Citation: Migliorini F, Eschweiler J, Götze C, Driessen A, Tingart M, Maffulli N. Matrix-induced autologous chondrocyte implantation (mACI) versus autologous matrix-induced chondrogenesis (AMIC) for chondral defects of the knee: a systematic review. Br Med Bull. 2022 Mar 21;141(1):47-59. doi: 10.1093/bmb/ldac004. PMID: 35175354; PMCID: PMC9351375.
Forum discussions
- cartilage damage: cartiform vs maci vs allograft
Patients compare and contrast the various cartilage repair procedures.
- Right at the start! ACI/MACI. Dr Briggs.
A very active patient walks us through his decisions and procedures for mACI.