Minced cartilage for focal cartilage defects—A comprehensive systematic review of surgical techniques in clinical studies, animal studies and basic research studies

PURPOSE: This study aimed to determine whether the minced cartilage procedure for treating focal cartilage defects is already a standardized technique. METHODS: A systematic literature review was conducted in MEDLINE (PubMed), EMBASE and Google Scholar to include all relevant studies (clinical studies, animal studies and basic research) investigating minced cartilage for treating focal cartilage defects. RESULTS: A total of 8 clinical studies, 14 animal studies and 17 basic research studies met the inclusion criteria. Among the eight clinical studies, one was a randomized controlled trial (minced cartilage vs. microfracture), one was a matched-cohort study (minced cartilage vs. autologous matrix-induced chondrogenesis), while the other six studies were case series with a small number of patients (maximum 28). Defect localization varied among the studies: most frequently femoral condyle defects were treated, followed by trochlea/patella. In three studies, cartilage was harvested and minced with a scalpel; in two studies, cartilage was harvested and minced with a shaver. The other clinical studies used a mixture of a curette, a scalpel or a shaver. Six studies used fibrin glue to seal the implanted cartilage. In three studies, a matrix was used for defect coverage. In two studies, cartilage was additionally augmented with autologous blood products. All animal and basic research studies observed similar differences regarding each surgical step. CONCLUSION: A standardized minced cartilage procedure has not yet emerged. There are differences in the methods of cartilage mincing, cartilage fixation, cartilage coverage using matrices and augmentation with autologous blood products. LEVEL OF EVIDENCE: Level III.