Autologous Chondrocyte Implantation in Cartilage Repair

Autologous chondrocyte implantation (ACI) represents a landmark in the field of cartilage repair, offering a cell-based approach to regenerate focal defects in articular surfaces. The procedure involves harvesting healthy chondrocytes from a non-load-bearing region of the patient’s joint, expanding them in vitro, and implanting the autologous cells into the damaged cartilage site. Early generations of ACI relied on a periosteal flap to secure the implanted cells, whereas subsequent techniques introduced bioresorbable scaffolds and collagen membranes to enhance cell retention and integration. Third-generation ACI further refined this process by seeding cultured chondrocytes onto three-dimensional matrices, improving cell distribution and promoting hyaline-like tissue formation. Despite demonstrated clinical efficacy in young and active patients, challenges remain in achieving consistent tissue quality, managing variable patient responses and mitigating risks of reoperation. Ongoing work seeks to optimise cell density, biomaterial carriers and postoperative rehabilitation protocols. The global significance of ACI is underscored by its application across joints and evolving indications, from isolated osteochondral lesions to complex cartilage pathologies, thus helping to delay or prevent osteoarthritis and joint replacement surgery.

Research from Nature Portfolio

Recent clinical comparisons of membrane coverings in atelocollagen-assisted ACI have highlighted the benefits of a collagen membrane as an alternative to traditional periosteal coverage. In a cohort of patients treated with a specially cultured cartilage product, both periosteum-covered and collagen-covered implantation resulted in significant improvements in patient-reported outcomes over two years. However, the collagen membrane group exhibited superior cartilage repair grades on second-look arthroscopy and a reduced incidence of adverse events. These findings support the use of collagen scaffolds to streamline the surgical procedure, reduce donor-site morbidity and enhance the quality of regenerated cartilage tissue.

Autologous Chondrocyte Implantation in Cartilage Repair publication trend

The graph below shows the total number of articles in autologous chondrocyte implantation in cartilage repair across all publications each year (not limited to Nature Index journals).

Technical terms

Autologous chondrocyte implantation (ACI): A surgical technique in which a patient’s own cartilage cells are harvested, expanded ex vivo and reintroduced into a cartilage defect to promote tissue regeneration.

Hyaline cartilage: A smooth, glossy form of cartilage that covers joint surfaces, enabling low-friction movement and load distribution.

Periosteum: A fibrous membrane covering bone, traditionally used to contain chondrocytes in first-generation ACI procedures.

Collagen membrane: A biodegradable scaffold composed of collagen fibres that secures chondrocytes within a defect and supports organised matrix deposition.

Extracellular matrix (ECM): The network of proteins and glycosaminoglycans surrounding cells, essential for cartilage structure, resilience and function.

References

1. Increased risk of reoperation and failure to attain clinically relevant improvement following autologous chondrocyte implantation of the knee in female patients and individuals with previous surgeries: a time‐to‐event analysis based on the German cartilage registry (KnorpelRegister DGOU). Knee Surgery, Sports Traumatology, Arthroscopy (2023).
2. Cartilage Defect Treatment Using High-Density Autologous Chondrocyte Implantation (HD-ACI). Bioengineering (2023).
3. Comparative study on clinical outcomes in autologous chondrocyte implantation using three-dimensional cultured JACC® with collagen versus periosteum coverings. Scientific Reports (2024).
4. Latest Advances in Chondrocyte-Based Cartilage Repair. Biomedicines (2024).