The goal of performing a microfracture is to get “scar cartilage” (fibrocartilage) to fill a cartilage defect. Microfracture can be performed arthroscopically and is often done in conjunction with other procedures such as chondroplasty and meniscectomy. Microfracture only works for smaller sizes and types of cartilage injury. The basic idea is to make multiple small holes in the bone at the cartilage lesion so bone marrow will fill the defect and develop into scar cartilage. This is not normal cartilage, but can help to prevent the cartilage lesion from expanding.
Microfracture does significantly change the post-operative recovery, including at least four weeks of non weight-bearing (crutches). Supervised physical therapy is essential for a smooth recovery after a microfracture, and running and athletic activities are not allowed for at least 4-6 months to allow the cartilage to mature.