More research is focused now on tissue regeneration for bone repair in humans. Stem cells from the person’s own bone marrow have two major advantages: the patient does not experience cell rejection and this source of stem cells avoids the controversy over the use of embryonic stem cells. Stem cells are useful because they can divide and develop into any type of cell in the body (including bone or cartilage).
Surgeons can remove or aspirate stem cells from the sternum (breast bone), vertebrae (spinal bones), and iliac crest (top of the pelvic bones). Studies are ongoing to investigate the effect(s) of removing stem cells from these areas and comparing results among the various harvest sites.
In this study, use of stem cells were compared between the anterior iliac crest and posterior iliac crest. Twenty-two adult donors (ages 18 to 72) participated in the study. A total of 20 mL of bone marrow was withdrawn using a collecting needle (skin puncture) in three places along the iliac crest.
The cells were taken to a lab and processed. The different types of cells were separated and counted in the first step of the process. Then the cells were prepared in such a way to allow them to replicate (grow and multiply) over a period of 14 days. The total number of cells was recounted with a particular focus on one type called connective-tissue progenitor cells. These cells are especially useful for repair of connective tissue.
Connective-tissue progenitor cells are somewhat limited in bone marrow tissue. And usually the number of stem cells used in tissue repair is in the millions. So finding the site with the best yield will be helpful. However, there are many, many different factors that can affect the total yield of these cells. Site of harvest in only one. The age and sex of the patient may make a difference. And although 14 days was the time period used in this study, it’s possible that other time periods would yield different results.
The results of this study showed that bone marrow harvest of cells that become connective-tissue progenitor cells was better from the posterior iliac crest. In fact, there were 1.6 times more of these cells in the posterior compared with the anterior iliac crest.
The number of stem cells collected and the speed at which they reproduced was the same between the two harvest sites. The two sites also produced an equal number of other types of cells useful for cartilage repair, formation of fat, and glycosaminoglycans needed for smooth joint motion. In summary, stem cells from the posterior iliac crest produce a greater yield of progenitor cells needed for bone repair.