New treatments for damaged knee cartilage are being developed. Young, active patients are the most likely candidates for this treatment approach. Various cartilage repair techniques are reviewed in this article.
The treatment methods discussed include microfracture, autologous chondrocyte implantation (ACI), and osteochondral grafts. Each of these procedures is used for small areas of damage to the cartilage called focal defects. There are benefits and drawbacks to each treatment method.
Microfracture involves drilling tiny holes through the cartilage to the bone. Cells and growth factors from the bone marrow seep through the holes to form a superclot. The tissue continues to repair itself over the next six to 12 months.
ACI uses a small amount of the patient’s own healthy cartilage. The tissue is harvested from the patient, purified, and expanded. Then it is reimplanted into the damaged area. Success rate with ACI is between 60 to 80 per cent.
Microfracture and ACI treatment to promote regeneration of joint cartilage do not restore the cartilage completely. Osteochondral grafting does restore the hyaline cartilage. In this operation, donor plugs of bone and cartilage are used to fill any area of the recipient’s joint. Problems can occur with tissue rejection and disease transmission anytime donor tissue is used.
Future methods of treating articular cartilage defects are expected to develop. The authors believe full restoration of damaged cartilage in patients with osteoarthritis will someday be possible. New methods of tissue engineering may reduce treatment to a single surgical procedure.