The Illustrative Third Generation Autologous Chondrocyte Implantation for Cartilage Repair: The Gel Based ACI Technique

Abstract

Autologous chondrocyte implantation (ACI) has evolved over many generations. The third-generation ACI evolved with cultured chondrocytes directly seeded on a membrane in the laboratory itself and then transported to the operating room for an implantation. This eliminated the need for suturing of a periosteum/membrane during the surgery [1–4]. The third-generation ACI technique further evolved from a monolayer distribution of the cells to the 3-dimensional distributions of the cells by using 3-dimensional scaffolds. Hyalograft-C and BioSeed C are some of the third-generation 3-dimensional scaffold-based ACI [5, 6]. These techniques helped to overcome many disadvantages associated with the first- and second-generation ACI, like graft hypertrophy, poor access to the lesion, membrane suturing and monolayer distribution [5–8]. Chondrocytes grown on a monolayer have a tendency for a slow growth, dedifferentiation and a switch of collagen synthesis from type II to type I [7, 8]. As any chondral defect is a 3-dimensional defect, it is quite logical to fill the defect with a 3-dimensional repair method. Gel-based ACI is a third-generation 3-dimensional scaffold-based technique that allows a 3-dimensional distribution of the autologous cultured chondrocytes in a scaffold that is made of fibrin glue [9–11]. As it is gel based, the scaffold can take any shape and does not require lesion preparation in the form of an oval/round shape. The purpose of this chapter is to illustrate the step-by-step technique and the postoperative rehabilitation of a gel-based third-generation ACI in an ideally indicated case.