In this procedure tiny holes called are made in the surface of the knee joint. This is called microfracture. The purpose is to release droplets of fat and blood from the bone through the holes into the area of damage or defect.
Tiny clots form filling in and plugging up the holes. A bond forms between the clot, bone, and cartilage. The end result will be a new surface layer of repair tissue where the original defect was present.
The doctor has probably advised you not to put weight on that leg for at least six weeks. By now you are starting to do so and will gradually advance to full-weight bearing. How fast you go depends on the size and location of the lesion. Painful symptoms may also limit you at first.
The surgeon will order repeat MRIs to help assess the status of the healing tissue. Another arthroscopy to look inside the joint isn't usually required. The MRI will show how much cartilage filling has taken place. The MRI is very sensitive to cartilage and will also show the status of the underlying subchondral bone plate.
Your surgeon will use all of this information to give you guidelines for activity in the weeks and months ahead of your recovery. If you follow his or her advice, you should be very safe.