This is a cartilage repair technique that aims to treat areas of full-thickness (bare bone) cartilage loss by reliably encouraging growth of fibrocartilage over the defect.
Fibrocartilage is not as good as the original articular cartilage that existed before the cartilage damage occurred, but it is capable of giving excellent coverage of the defect and good relief of pain.
The technique is commonly used to treat small to medium cartilage defects, but we have had many successes treating even large defects with this technique. One of the great advantages of microfracture is that it can be performed arthroscopically (through a key-hole technique). A special instrument is used to create multiple small holes in the bare bone that allow bone marrow contents and some blood to come through from the underlying marrow cavity. This forms a localised stable clot that contains cells that can turn into fibrocartilage.
Sometimes we use a special gel substance (Cartifill) in association with the micro fracture technique that acts as a scaffold to ensure that the special cells do not escape into the knee joint (one stage chondral grafting). It has been the norm for patients to be told to use crutches and to put minimal or partial weight through the knee for 6 weeks. We do not do this, but use an accelerated rehabilitation approach where patients offload the knee for 10-14 days only then bear full weight on the knee. Crutches are used for 3-4 weeks.
We have used this technique as a joint preservation strategy in patients with arthritic areas confined to one knee compartment and have had extremely encouraging results and very happy patients.