Autologous Chondrocyte Implantation With Collagen Membrane.

The first-generation autologous chondrocyte implantation (ACI-P) described by Peterson and colleagues used a periosteal patch to form a watertight cover over the articular cartilage defect, under which the autologous chondrocyte suspension was injected. Although good to excellent outcomes were often seen in >80% of patients and the durability of the repair documented up to 20 years, the procedure was noted to have a high rate of subsequent surgical procedures, most often for arthroscopic debridement of periosteal hypertrophy or incomplete incorporation. Consequently, the surgical technique advanced to use a porcine-derived bilayer of type I/III collagen with a porous layer that favors cell attachment and a smooth, compact layer that is cell occlusive. In use of the collagen membrane ACI, prospective studies have shown no diminution in clinical results and a marked reduction in subsequent surgeries from graft hypertrophy to <3%. Use of the collage membrane for ACI-C in the United States is currently an off-label use of an FDA-approved membrane, which should be discussed with the patient before surgery.