In Vivo Evaluation of Different Surgical Procedures for Autologous Chondrocyte Implantation.

Objective: Autologous chondrocyte implantation (ACI) involves the application of a chondrocyte suspension into a membrane-sealed cartilage defect. Recently, "cell-seeded collagen matrix-supported" ACI has been developed wherein chondrocytes are seeded on a biomembrane. This study aimed at preclinically comparing 4 variant ACI techniques in a refined goat model: 2 traditional procedures, whereby the defect is sealed by a periosteal flap or collagen membrane, and 2 cell-seeding methods, with the collagen membrane either sutured or glued into the defect.

Design: The efficacy of the surgical techniques was evaluated in an acute critical size chondral defect in the medial condyle of 32 skeletally mature goats, randomly assigned to 1 of the 4 aforementioned treatment groups. After 10 weeks in vivo, the quality of the repair was graded histologically by 2 independent, blinded readers using the "modified O'Driscoll" score.

Results: The cell-seeding procedure whereby the membrane is sutured into the defect has a similar structural repair capacity than traditional ACI techniques. However, when the cell-seeded membrane was glued into the defect, the outcome appeared inferior.

Conclusion: These findings indicate that optimizing the goat model and the postoperative recovery does allow preclinical evaluation of ACI-based cartilage implants in a load-bearing setting. This preclinical observation provides support to the clinical utilization of the sutured membrane-seeded (ACI-CS) technique, provided sutures, but not fibrin sealants, are used to fix the cell-seeded membrane in the defect bed.