Is a cartilage defect the same as arthritis?
No! And this is very important to understand, as the treatments for a cartilage defect and the treatment of arthritis are very different. The treatments for cartilage defects are not appropriate, under any circumstance, for patients who have widespread arthritis of a joint. Performing any of the following procedures in a patient with arthritis will lead to a poor result.
What are the treatment options for a patient with a cartilage defect?
Treatment of a cartilage defect always begins with conservative treatments. These include medications, physical therapy, possibly injections, and other options. If these treatments do not work, some options include:
Microfracture is a treatment used to stimulate the body to grow cartilage in an area of damage. In a microfracture procedure, the firm outer layer of bone is penetrated, to expose the inner layers of bone where marrow cells exist. These cells can then access the damaged area and fill in the gap of cartilage.
- Pros: Microfracture is the least invasive of these options, requiring only one surgery and can be completed entirely arthroscopically. It is a safe and reliable procedure, and the results have been good in most patients.
- Cons: The new cartilage that fills in the gaps in a microfracture procedure is not the same as normal joint cartilage, and there are concerns it will not hold up over time. Patients must be willing to participate in post-operative rehabilitation, which includes a period of limited weight-bearing.
Cartilage transfer involves moving cartilage from healthy parts of the joint to damaged areas. Small plugs of cartilage are removed, with a portion of underlying bone, and transferred to the area of damage. The plugs are taken from areas of the joint where the cartilage surface is not needed.
- Pros: Cartilage transfer is best suited for patients with focal (small) areas of cartilage damage. This procedure uses healthy cartilage tissue and the damaged area is immediately fit with good cartilage.
- Cons: Cartilage transfer is currently only in use in the knee joint (and very rarely in the ankle) of individuals who have a small area of cartilage damage, not widespread arthritis. The cartilage defect must be of a small enough size that the plugs will adequately fill the damaged area.
Cartilage implantation, also called autologous chondrocyte implantation (ACI), is a newer procedure used to grow cartilage cells. The surgeon removes some cartilage cells for growth in a cartilage cell expansion laboratory. Once enough cells have been artificially grown, they are re-implanted into the damaged joint.
- Pros: The theory is that if we can't get cartilage to grow inside the human body (in vivo), we can grow it outside (in vitro) and then put it back in. Short-term studies indicate few adverse side effects of cartilage implantation.
- Cons: As with the cartilage transfer, cartilage implantation is currently only in use in the knee joint of individuals who have a small area of cartilage damage, not widespread arthritis. Cartilage implantation involves multiple surgeries, and the complete rehabilitation can take more than a year.