Photo: Getty Images
In adults with deep cartilage defects, autologous chondrocyte implantation (ACI) has been used for over 30 years and has been further developed and modified over time. The most recent method, the matrix-associated ACI, shows beneficial effects that suggest a benefit that is at least comparable to the therapeutic alternatives. For the other two older procedures, collagen-covered ACI and periosteal-covered ACI, no advantages can be seen.
This is the conclusion of the final report that the Institute for Quality and Efficiency in Health Care (IQWiG) has now submitted on behalf of the Federal Joint Committee (G-BA). The patient-relevantbenefit of all three generations of chondrocyte implantation (ACI) - periosteal covered (ACI-P), collagen covered (ACI-C), or matrix-associated (M-ACI) was examined.
Matrix-Associated ACI Offers Technical Advantages
For the treatment of cartilage defects in adults that affect more than 50 percent of the depth of the cartilage or that extend into the bones below, autologous chondrocyte implantation (ACI) has been a long-standing therapeutic method in Germany. Today, the matrix-associated ACI (M-ACI) is the most widely used technique, and the two older methods, ACI-C and ACI-P, are no longer of practical relevance according to several statements on the preliminary report.
In the two-stage procedure, cartilage is first removed, cultivated in the laboratory, and then reintroduced into the defect in a second step. With M-ACI, the cultivated cartilage cells are fixed directly in a carrier matrix and applied to the cartilage defect zone. This technical advance saves the laborious fixation and the watertight closure of a cell suspension in the cartilage defect, which is necessary with the older procedures - with ACI-P using periosteum or with ACI-C with a collagen membrane. Overall, this makes the surgical procedure much easier.
Beneficial Effects Only with M-ACI
On the basis of a meta-analysis of the study data from seven RCTs, it can be assumed that the M-ACI method has a benefit that is at least comparable to that of treatment alternatives such as microfracture or mosaic plastic: There were statistically significant effects in favor of M-ACI for knee function and the health-related quality of life, but not on a clinically relevant scale. Almost without exception, the results on other endpoints also point towards an advantage of M-ACI, so that overall a benefit that is at least comparable with the therapeutic alternatives can be determined for M-ACI.
The two older methods ACI-P and ACI-C consistently deliver poorer results when viewed individually: On the basis of partly inconsistent results from two RCTs, neither a benefit of ACI-C and ACI-P is discernible nor can a comparable benefit be recognized Identify therapy alternatives.
About the Report Creation Process
IQWiG published the preliminary results, the preliminary report, in June 2020 and put them up for discussion. After completing the commenting procedure, the project team revised the preliminary report and sent it to the client, the G-BA, as a final report in November. The final report contains changes resulting from the commenting procedure. The written comments received are published in a separate document at the same time as the final report.