Cartilage Transfer Surgery of the Knee

Osteochondral autograft transfer system (OATS) and mosaicplasty are surgeries that are done to treat severe cartilage damage in the knee joint. These procedures involve autologous (from your own body) transfer of cartilage from healthy areas to damaged areas.

You have a number of treatment options if the cartilage in your knee joint is damaged. Typically, treatment begins with non-invasive approaches, such as pain medication and physical therapy. If these treatments are not effective, more invasive treatments, including surgical options, might be necessary. If you have small, isolated areas of cartilage damage, a cartilage transfer surgery could be considered.

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Cartilage Transfer Surgery

During these procedures, cartilage is taken from non-weight-bearing areas of the knee. The idea behind this approach is that the body will not miss this cartilage and it can be used where it is needed. Over time, the holes left from where the plugs are taken will fill with bone and scar tissue.

• Mosaicplasty: During mosaicplasty, your surgeon moves round plugs of cartilage and underlying bone to damaged areas. The plugs are each a few millimeters in diameter, and when multiple plugs are moved into a damaged area, the small plugs of cartilage look like mosaic tiles.
• OATS: The plugs used in an OATS procedure are larger than those used in mosaicplasty, and only one or two plugs are used to fill the area of cartilage damage

Performing Cartilage Transfer Surgery

Prior to your cartilage transfer procedure, your surgeon will inspect your knee joint arthroscopically (with a small incision and a small camera) to see if you have an area of cartilage damage that is suitable for cartilage transfer.

Steps of your procedure:

1. The first step is the preparation of the area of damaged cartilage. A coring tool is used to make a perfectly round hole in the bone in the area of damage.
2. The next step is harvesting the plug of normal cartilage. The plug is taken with the underlying bone and sized to fit snugly into the hole that was prepared in the area of damage.
3. The final step is the implantation of the harvested plugs into the hole that was created in the damaged area. Over time, the implanted bone and cartilage should incorporate into its new environment.

Cartilage transfer surgical procedures are done arthroscopically in an operating room, but there is no overnight stay in the hospital. The surgery can be done either under general anesthesia or with a regional nerve block for pain control.

Recovery

After surgery, your leg will likely be placed into a brace, and you will be given crutches or a walker to prevent you from having to place weight on your surgical leg.

A typical recovery following cartilage transfer surgery takes approximately six to nine months. The first few months are the most arduous in terms of rehabilitation and recovery.

Activity

Once your surgeon feels that it is safe for you to place weight on your surgical joint, you will gradually increase the amount of weight-bearing on the healing joint.

Most surgeons will not allow any competitive sports activities until at least six months after surgery. Before you can go back to athletic activities, your surgeon will confirm that you have regained full mobility and strength.

Complications

The most common risks of knee arthroscopy include infections and blood clots. These are uncommon complications, but when they do occur, they can be serious.

After cartilage transfer surgery, there is a possibility that the transfer cartilage might not remain healthy.

Another possible complication is pain at the site where the healthy cartilage was obtained. Your surgeon will try to only obtain cartilage from areas where your knee does not need protection. However, some people report donor site pain after the procedure.

A Word From Verywell

Cartilage transfer surgery is a possible treatment option if you've had small, contained areas of cartilage damage within your knee joint. This same surgical procedure has also been used in other joints, but it is by far most common in the knee joint.

If you have cartilage damage due to widespread arthritis, you would not be a candidate for a cartilage transfer procedure. Successful outcomes from cartilage transfer surgery are most dependent on careful surgical technique and compliance with postoperative precautions.