Autologous chondrocyte implantation, matrix‐induced autologous chondrocyte implantation, osteochondral autograft transplantation and osteochondral allograft improve knee function and pain with considerations for patient and cartilage defects characteristics: A systematic review and meta‐analysis

Abstract Purpose Previous studies have reported on the outcomes of autologous chondrocyte implantation (ACI) versus matrix‐induced ACI (MACI) and microfracture. Specific clinical outcomes of ACI, MACI, osteochondral autograft transplantation (OAT) and osteochondral allograft (OCA) have not been well studied. The purpose of this systematic review and meta‐analysis was to analyze the outcomes of these regenerative surgical techniques with an emphasis on comparing their effectiveness using the International Knee Documentation Committee (IKDC) subjective score, the Lysholm Knee Scoring Scale, the Tegner Activity Scale and the Visual Analogue Scale (VAS) score for the surgical treatment of tibiofemoral joint cartilage defects. Methods An electronic search of MEDLINE, Embase and Cochrane Library was performed to identify studies that reported clinical outcomes for ACI, MACI, OAT and OCA procedures. The literature review was conducted following Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines and only studies involving cartilage defects in the tibiofemoral joint were included. Outcomes were measured with the IKDC evaluation, Lysholm Knee Scoring Scale, Tegner Activity Scale and the VAS. Outcomes were compared to the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS). The methodological quality of the included studies was analyzed by the Methodological Index for Nonrandomized Studies and the Jadad scale. Results Forty‐seven studies were included representing a total of 1993 patients with a mean follow‐up time of 57.2 ± 40.3 months (range: 4.0–160.0 months). The location of cartilage defects was reported in 46 studies, with a total of 1922 cartilage defects. There were 1277 medial femoral condyle cartilage defects, 488 lateral femoral condyle cartilage defects, 139 unspecified femoral condyle cartilage defects and 18 tibial plateau cartilage defects. All four procedures reported significant improvements in the Lysholm, IKDC, Tegner and VAS scores with no significant differences between them. The OAT technique surpassed the PASS threshold for the IKDC score while all four techniques surpassed the PASS threshold for Tegner and Lysholm scores. Additionally, all procedures met the MCID for each clinical outcome. Conclusion This systematic review and meta‐analysis indicate that ACI, MACI, OAT and OCA all result in significant improvements in knee function and pain for cartilage defects of the tibiofemoral joint. When selecting a procedure, patient and cartilage defect characteristics should be assessed to determine the best technique for each individual patient. Study Design Systematic review and meta‐analysis. Level of Evidence Level III.