As a healthy bone marrow starts to deteriorate, because of either diseases like leukemia, aplastic anemia, lymphoma, or osteomyelitis or procedures such as chemotherapy and radiation, it needs to be replaced with a matching donor bone marrow. This procedure is called as bone marrow transplants, wherein, the blood stem cells traverse towards the marrow with an aim to produce new blood cells which in turn helps in promoting the growth of new marrow.

Most often, a bone marrow transplant procedure is carried out in patients with blood cancers or osteomyelitis. Bone marrow transplant can be used to treat a variety of other diseases including -

1. Aplastic anaemia, a disorder wherein the creation of new blood cells in affected bone marrow ceases.

2. Congenital neutropenia, an inherited disorder that results in chronic infections.

3. Cancers of bone marrow including leukaemia, lymphoma, and multiple myeloma.

4. Neuroblastoma, where "neuro" means nerves, & "blastoma" means cancer that has an effect on the developing or immature cells, is mostly seen in and around adrenal glands. Neuroblastoma can also arise in other parts of the body such as the abdomen, chest, neck, spine.

5. Thalassemia, a genetic blood disorder that compels the human body to form haemoglobin in an abnormal form.

6. Hurler's syndrome is a congenital disorder causing metabolism malfunction, it is a rare form of mucopolysaccharidosis type 1, lysosomal storage disorder can cause a wide range of problems that may include, skeletal abnormalities, respiratory issues, diminished life-expectancy period etc.

7. Sickle cells anaemia, a genetic blood disorder that results in misshapen red blood cells.

8. Adrenoleukodystrophy, a genetic abnormality that can destroy myelin leading to seizures and hyperactivity.

9. Immune deficiency disorder, a condition when the body loses its capability to combat infections and diseases efficiently.

Types of bone marrow transplants (BMT):

Bone marrow transplant procedures are of two main types -,

1. Autologous BMT

2. Allogenic BMT

Apart from the primary ones mentioned above, there is another type of bone transplant procedure, called as haploidentical transplant.

1. Autologous bone marrow transplant: During this procedure, the patient's stem cells are eliminated from their body, prior to giving the high-dose chemotherapy, or radiation treatment. The collected stem cells are stored in a freezer. Following the chemotherapy or radiation procedure, the stem cells are put back in the patient's body to promote the creation of normal blood cells. Umbilical cord blood transplant is another type of autologous bone marrow transplant. Umbilical cord blood transplant is a procedure that involves removal of a newborn baby's umbilical cord precisely after the birth. The stem cells collected are frozen and stored until the need for a transplantation arises in the patient. Since the umbilical cord blood cells are highly immature, there is less of a need for perfect matching.

2. Allogeneic bone marrow transplant: During this procedure, stem cells are removed from another person, commonly called as a donor (preferably, the patient's brother sister, parents or closed relatives). In the majority of the cases, the donor's genes ought to match (at least partially) the genes of the patient.

3. Haploidentical transplant: Stems cells of a donor can be used even when the donor fails to match to the entire set of criteria with the help of haploidentical transplant procedure. Hence, this type of transplant helps in amplifying the size of the pool of donors.

The type of procedure used by the bone transplant surgeon depends on various factors such as extent and severity of the damage caused along with the age and health condition of the patient being treated.