Autologous chondrocyte implantation

Autologous Chondrocyte Implantation (ACI) is a biomedical treatment that repairs damages in articular cartilage. ACI provides pain relief while at the same time slowing down the progression or considerably delaying partial or total joint replacement (knee replacement) surgery. The goal of ACI is to allow people suffering from articular cartilage damage to return to their old lifestyle; regaining mobility, going back to work and even practicing sports again.

ACI procedures aim to provide complete hyaline repair tissues for articular cartilage repair. Over the last 20 years, the procedure has become more widespread and it is currently probably the most developed articular cartilage repair technique.

The surgical technique was first published on humans by Brittberg in 1994. He reported good and promising results with 23 patients for defects on the femoral condyles (Brittberg et al., 1984).The technique also seems promising with regard to long-term results.

How Autologous Chondrocyte Implantation works

This cell based articular cartilage repair procedure takes place in three stages. In a first stage, between 200 and 300 miligrams chondrocyte cells are sampled arthroscopically from a non weight bearing area from either the intercondylar notch or the superior ridge of the medial or lateral femoral chondyle of the patient. These harvested cells are grown in vitro in a specialised laboratory for approximately four to six weeks, until there are enough cells to reimplant on the damaged area of the articular cartilage. The patient then undergoes a second treatment, in which the chondrocyte cells are applied on the damaged area during an open-knee surgery (also called arthrotomy). These autologous cells should adapt themselves to their new environment by forming new cartilage. During the implantation, chondrocyte cells are applied on the damaged area in combination with a membrane (tibial periosteum or biomembrane) or pre-seeden in a scaffold matrix.

The Next Steps in ACI - Using Characterized Chondrocyte Implantations (CCI)

The latest development in cell-based cartilage repair consists in of screening cartilage cultures on their cartilage forming abilities before implanting them on the damaged cartilage. This extra quality-release criterion aims to solve the risk of de-differentation of the cells during their culturing process. De-differentiation of cells means that the cultured cells lose their primary characteristics (the cartilage forming ability in case of chondrocytes). This process is referred to as Characterized Chondrocyte Implantation (CCI). Currently, the only therapy for CCI is ChondroCelect.

In February 2008, a scientific publication in the American Journal of Sports Medicine showed that CCI results in better structural repair than standard microfracture surgery when treating symptomatic cartilage defects of the knee.

External links

• "Characterized Chondrocyte Implantation Results in Better Structural Repair When Treating Symptomatic Cartilage Defects in the Knee in a Randomized Controlled Trial Versus Microfracture" The American Journal of Sports Medicine, volume 36 number 2, pp 235–246, February 2008
• Hangody, L. and P. Fules. "Autologous osteochondral mosaicplasty for the treatment of full-thickness defects of weight-bearing joints: ten years of experimental and clinical experience." J.Bone Joint Surg.Am. 85-A Suppl 2 (2003): 25-32.
• Peterson, L., et al. "Two- to 9-year outcome after autologous chondrocyte transplantation of the knee." Clin.Orthop.374 (2000): 212-34.
• Steadman, J. R., et al. "Outcomes of microfracture for traumatic chondral defects of the knee: average 11-year follow-up." Arthroscopy 19.5 (2003): 477-84.
• Hambly K, Bobic V, Wondrasch B, Van Assche D, Marlovits S. Autologous chondrocyte implantation postoperative care and rehabilitation: Science and practice. Am J Sports Med. 2006;34(6):1020-1038.
• “Autologous Chondrocyte implantation (ACI 2002 Update). Department of labor and Industries Office of the Medical director Technology Assessement. 2002. [1]. April 14, 2006.
• “Cartilage Transplantation”. University of South Alabama Human Performance and Joint Restoration Center. USA Department of Orthopaedics. [2]
• Minas, Tom. Autologous chondrocyte implantation for full thickness cartilage defects of the knee. Brigham and Women’s Hospital, Cartilage Repair Center. [3]
• “Minimally Invasive Total Knee Replacement.” American Academy of Orthopaedic Surgeons. [4]. February 2005.
• BBC Coverage of Autologous Chondrocyte graft in UK
• UK Health Charity covers Autologous Chondrocyte grafts