These undifferentiated cells are found at particular sites within our body. These cells are the precursor forms of the cells of the tissues of the body. This means that they do not have a specific form, and that at some point in their life the body puts them to use in a specific direction. If, for example, there is a muscle injury in which muscle tissue has been destroyed, the body will recruit such cells and turn them into muscle cells so that they fill the gap in that particular area. In this way the body is able to heal its wounds at any point in the body. This means that our body holds a reserve of cells which, under the right conditions, can be used for regenerative purposes.
It has been observed that a large quantity of such cells is found in the bone marrow of our body. Such bones are the iliac bones and the cancellous parts of the femur, the tibia and the humerus. These areas are therefore now used routinely for harvesting such cells. Unlike older techniques, in which a small quantity of cells was taken and then multiplied in a laboratory, today the technique is carried out by taking them from the bone marrow and using and injecting them directly into the area of interest.
The two commonest harvest sites are the region of the pelvis and of the femur, from which the cells are taken with a special instrument (a thick needle) under local anaesthesia or sedation. The blood collected is then placed in a special machine called a centrifuge, which produces a fraction rich in cells. This fluid is then injected into the affected area. The technique takes a few minutes and the patient can get up and move as soon as the local anaesthesia or sedation wears off, and leaves the clinic the same day.
The use of these cells has spread to many fields of medicine, and in orthopaedics it is used widely for damage to the soft tissues in particular, that is to say problems with the articular cartilage, with the menisci in the knee or with the labrum in the hip. Their use has of course also spread to other conditions such as bone lesions, large soft-tissue defects and so on. The use of these cells is a more advanced treatment than the use of biologic agents and is regarded as a more effective method. The first results in the literature are quite encouraging, and indeed in many cases these cells are used as an adjunct to many common surgical procedures.
