CARTILAGE INJURY – CONDITIONS & TREATMENTS
Cartilage is a permanent tissue with very minimal healing potential. It is the best shock absorber of nature. Friction between two layers of cartilage while moving is about a hundred times slower than two pieces of ice sliding over each other.
Cartilage lacks blood supply and gets oxygen due to joint mobility diffusing water and nutrients into the cartilage; hence an injury to the cartilage never heals.
It has been the quest and a dream in the orthopedic scientific community to get the cartilage to heal as cartilages lack nerve supply. Injury to it is painless but as the cartilage damage progresses the bone under the cartilage gets exposed and the pain starts. In addition to it the joint capsule and layer of synovial are extremely painful as well. So it is rightfully said that when a joint is in pain continuously then the patient might already have passed the age of cartilage restoration.
At some point, cartilage problems were being treated with micro-fracturing, while cartilage forming chondrocytes were also being attempted to be grown in vitro or in a laboratory. Sometime in the mid-1990’s it became possible to grow the chondrocytes in a laboratory and then they were transferred into the joint. This procedure was called the autologous chondrocyte implantation. This procedure has passed through many obstacles and is now an accepted form of treatment. It is a patient-friendly gel-based technology.
This procedure entails cartilage cells being grown and then implanted in a crater to form a gel in an estimated time of 10 minutes and it ensures that the gel stays in the implant till the chondrocytes mature within 1 to 1.5years. Initially, it is loaded slowly and as time progresses the loading increases. Theoretically, if the patient is treated at an early cartilage defect stage of osteoarthritis with this treatment, then the progression of the cartilage damage can be stopped. This procedure may require a follow-up for 20 odd years.
When is the Chondrocyte implant treatment used?
The autologous chondrocyte implant may be used only if cartilage defect is unifocal which means when only one surface of a joint is damaged.
Does the size of the defect matter?
Yes, the size of the defect matters. It is useful for large defects including almost full condyle. Any defect with the size exceeding 10mm does not heal well with micro-fracturing and requires the chondrocyte implant to heal the unifocal as well.
Hence it is a two-part surgery. The first surgery involves the arthroscopy and harvesting the cartilage, while the second surgery involves re-implanting the harvested cartilage. Even though it is essentially two surgeries, it is still minor for early knee conservation.
When cartilage defects have progressed and are bifocal or for patients above 60 years of age this autologous chondrocyte implant is not the right treatment plan for them.
Dr. Pradeep Kocheeppan
Apollo Speciality Hospitals, Jayanagar, Bangalore