Research into repair techniques for damage to knee cartilage is moving right along. Surgeons in Europe and Australia are ahead of American surgeons as they have moved from first-generation cartilage repair through second generation methods to the more current third-generation approaches.
As you have discovered, only one type of third-generation cell therapy for cartilage repair is available in the United States: the matrix-induced autologous chondrocyte implantation or MACI. Although it is being used by U.S. surgeons, the U.S. Food and Drug Administration (FDA) has not yet approved this type of cell carrier yet.
But studies from Europe have shown that the MACI method is safe and effective. Over 6000 procedures have been done since 1998. Although most of the published studies are case series or case reports, the results have been consistently the same.
Patients report significant improvements in pain, function, and activity level. Measurable results based on patient report and MRI studies were seen as early as three months after surgery but more often the benefits occurred during the first year.
Post-operative complications were rare and included infection, detachment of the transplant, and overgrowth of the graft. Overgrowth or hypertrophy can require a second surgery to smooth down the surgical area.