Summary

Report of the first 10 cases of Autologous Chondrocyte Implantation in a collagen Scaffold in Brazil. Chondrocytes were cultivated from biopsy. Immunofluorescence for collagen type-II, cellular viability at implantation, scanning electron microscopy of the implants were performed. There were no major complications. There was functional improvement and cartilage regenerate in follow-up MRI.

Abstract

Objectives:
Third generation autologous chondrocyte implantation (ACI) consists of implanting scaffold membranes previously seeded with cultivated autologous chondrocytes for the treatment of articular cartilage injury. This technique had not been previously available in Brazil. The objective of this study was to implement ACI and to report the initial experience and safety.

Methods

ACI was performed in 10 patients with average age 32,7+-10,9, with full-thickness cartilage lesions of the knee of average size 5,3±2,2 cm2. Treatment consisted of two surgical procedures: an arthroscopic biopsy of cartilage for isolation and expansion of chondrocytes, which were seeded in a type I/III collagen membrane scaffold, followed by implantation of the cell-seeded scaffold after lesion debridement. Additional surgery for associated injuries was performed when needed. Immunofluorescence for collagen type II of the cultured cells, cellular viability at implantation, scanning electron microscopy (SEM) and microbiological tests of the implants were performed. Clinical end-points were KOOS and IKDC functional scores an magnetic resonance imaging (MRI). Wilcoxon signed-rank test was performed, a=5%.

Results

Collagen type II was identified in cell cytoplasm, cell viability was greater than 95% at implantation, there was cellular adhesion in the scaffold fibers in SEM, and there was no microbiological contamination of any sample. Average clinical follow-up until this moment was 12.3 months (6.3 to 19.1), with five patients having more than 6 months. There were no major surgical complications, but 2 patients needed knee manipulation at 8 weeks due to gain range of motion. KOOS and IKDC functional scales improved from 74,7±9,2 e 55,12±11,1 preoperatively, to 77,7±16,2 e 62,3±19,2 at 3 months and 85,0±4,4 e 70,5±8,0 at 6 months. Nevertheless, there was no statistically significant difference between initial and 6 months scores, but we estimate the need for complete follow-up of 10 cases for a power of 80%. MRI showed regenerated tissue compatible with hyaline cartilage.

Conclusion

Third generation ACI is viable in our setting, having been safely and successfully applied in 10 patients. Longer follow-up is necessary to statistically demonstrate functional improvement.