Micro-fracture is one of several techniques used to stimulate the healing of discrete defects in chondral cartilage usually occurring in the weight bearing areas of the knee. It is suitable only for smaller defects, and most particularly for those surrounded by relatively healthy chondral cartilage. The technique is performed arthroscopically (usually on a day case basis) and involves the formation of small holes in the base of the defect through which marrow and blood cells can pass, bringing with them the potential for healing.
The principle disadvantage of micro-fracture is that, following surgery, a period of protected weight bearing is required using two crutches, and often of several weeks duration. Healing of defects treated in this way is usually assessed by the clinical resolution of symptoms and also by repeat MRI scanning. Relief of symptoms following micro-fracture is usually only appreciated by patients three to four months following surgery. When cartilage defects of this type are associated with knee deformity, micro-fracture is occasionally performed in association with knee osteotomy.