Success rates and immunologic responses of autogenic, allogenic, and xenogenic treatments to repair articular cartilage defects

Abstract

This review examines current approaches available for articular cartilage repair, not only in terms of their regeneration potential, but also as a function of immunologic response. Autogenic repair techniques, including osteochondral plug transplantation, chondrocyte implantation, and microfracture, are the most widely accepted clinical treatment options due to the lack of immunogenic reactions, but only moderate graft success rates have been reported. Although suspended allogenic chondrocytes are shown to evoke an immune response upon implantation, allogenic osteochondral plugs and tissue-engineered grafts using allogenic chondrocytes exhibit a tolerable immunogenic response. Additionally, these repair techniques produce neotissue with success rates approaching those of currently available autogenic repair techniques, while simultaneously obviating their major hindrance of donor tissue scarcity. To date, limited research has been performed with xenogenic tissue, although several studies demonstrate the potential for its long-term success. This article focuses on the various treatment options for cartilage repair and their associated success rates and immunologic responses.

FIG. 1.

Successful approaches to articular cartilage defect repair. Autogenic sources have shown success using isolated chondrocytes, native tissue autografts, and tissue-engineered constructs. Clinically, allogenic cell sources have only been successful when surrounded by an ECM in native tissue grafts and tissue-engineered construct. While xenogenic tissue has yet to be used clinically, based on this review of animal studies there exists a possibility to successfully repair cartilage defects using tissue grafts or tissue-engineered constructs, but not isolated cells. Asterisk (*) denotes approaches not currently used in clinical practice.