Older patients, or those with many lesions in one joint, are less likely to benefit from the surgery. Articular cartilage in the knee damaged in a single, or focal, location. The knee is the most common area for cartilage restoration. Ankle and shoulder problems may also be treated.he goal of microfracture is to stimulate the growth of new cartilage by creating a new blood supply. A sharp tool called an awl is used to make multiple holes in the joint surface. The holes are made in the bone beneath the cartilage, called subchondral bone. This creates a healing response.