Table 1 Eligibility criteria

Inclusion criteria

 Clinical studies reporting outcomes following mACI for chondral defects of the knee

 English, German, Italian, French, and Spanish languages

 Prospective studies with level I to II of evidence [22]

 Fashion of the surgical approach (arthroscopic or mini-open) clearly stated

 Length of the follow-up \(\ge\) 12 months

 Report quantitative data under the outcomes of interest

Exclusion criteria

 Animal or in vitro studies

 Other surgical approaches rather than arthroscopic or mini-open

 Studies reporting data on combined surgeries

 Studies reporting data on non-mACI procedures

 Studies enhancing mACI with other less committed cells

 Reviews, comments, letters, editorials, and techniques studies