Cartilage Repair Procedures

Autologous Chondrocyte Implantation (MACI)

For this procedure, a small piece of cartilage is harvested and the cartilage cells (chondrocytes) are multiplied in the lab. Four to six weeks later, the chondrocytes are implanted into the defect and over time form cartilage tissue to repair the cartilage defect. This technique is most suitable for larger defects.

The video on the left demonstrates aspects of the ACI procedure such as initial defect debridement and subsequent suturing of a collagen membrane.

Osteochondral Allograft Transplantation

In this procedure, bone and the attached cartilage from an organ donor is transplanted to repair cartilage damage. While technically a transplant, these cartilage transplants do not require anti-rejection medication as, for example, a kidney transplant does. This technique is most suitable for larger defects, especially when there is not only damage to the cartilage surface but also the underlying bone.

The video to the left demonstrates the appearance of an osteochondral allograft 3 months after transplantation with complete integration.

Click here for an additional information sheet on osteochondral allograft transplantation. Click here for a video on this procedure

MRI image of an osteochondritis dissecans (OCD) lesion in the trochlea (circled area with a depressed defect containing a loose fragment) of a 18yo man.

MRI image of an osteochondritis dissecans (OCD) lesion in the trochlea (circled area with a depressed defect containing a loose fragment) of a 18yo man.

MRI image of the same area now 6 months after treatment of the defect with osteochondral allograft transplantation. The transplant is almost completely integrated into the native bone

MRI image of the same area now 6 months after treatment of the defect with osteochondral allograft transplantation. The transplant is almost completely integrated into the native bone

Autologous Osteochondral Transfer (OATS or Mosaicplasty)

Small cylinders of bone and attached cartilage are harvested from a part of the patients knee that is more peripheral, and then implanted into the more centrally located damaged area of the same knee.

The video to the left demonstrates preparation of the recipient site prior to placement of an OATS plug.

Microfracture or subchondral drilling

After the defect is prepared, small holes are created at the base with an awl or a drill. Blood and cells from the underlying bone marrow cavity collect in the defect and slowly mature into a repair tissue. This technique is most suitable for small defects, since the resulting fibrocartilage (scar cartilage) is not strong enough to withstand the demands of filling a larger defect.

The video to the left demonstrates the microfracture procedure.

Umbilical cord mesenchymal stem cell transplantation (Experimental study)

After the defect is prepared, small holes are created at the base with a drill. Mesenchymal stem cells are isolated from umbilical cord blood obtained during routine delivery of healthy babies in the US. The umbilical cord and placenta are otherwise discarded after delivery. The stem cells are grown in culture to multiply them. During surgery, they are mixed with hyaluronan and pasted into the holes and the defect. The tissue matures over time to form cartilage.

The video to the left demonstrates the appearance one year after Cartistem procedure.