Bones without Marrow Mend Faster

Bone marrow is a very important tissue found in large bones within animals, such as hip and thigh bones. It generates stem-cells, the immature cells that develop into specialised cells, usually red and white blood cells, but they have the potential to develop into many other types.

This is the excitement shared by many doctors and scientists that work in the stem-cell research field, as they could be harvested and grown into new cells and tissues to combat or even cure many diseases such as Alzheimer's, Parkinson's, arthritis, diabetes and spinal cord injuries*.

So why would removing it help repair a weak or broken bone? It seems an obscure idea, yet it works when followed up with injections of a bone growth hormone, parathyroid hormone (PTH), that encourages the growth of a new bone.

The treatment was found in a recent study with rats**, where the marrow was syringed out of the left thigh-bone of each animal. Then half received daily injections of PTH. X-rays where then taken two weeks after the treatment.

After three weeks, the bones of rats who didn’t receive PTH treatment, showed bone marrow returning and reabsorbing any new bone cells that may have grown. Agnès Vignery ** observed that “this study suggests that bone marrow usually inhibits the formation of a new bone.”

Comparatively, those rats that had received PTH treatment showed that new bone had begun to form in the marrow cavity and that marrow had not returned. These left thigh-bones from the PTH treated rats where discovered to be stronger than their three other legs and the legs of the rats who hadn’t been given PTH injections.

Warren Levy*** believes that this procedure could radically change the way patients are treated, especially those with hip fractures. This often involves expensive surgery and it can be life-threatening to elderly people, “instead, if an X-ray reveals a fracture, you could go in with a needle right there in the doctor’s suite and do without surgery.”

Peter Kay**** also agrees that this new technique sounds very promising, “this sort of minimally invasive technique to replace surgery sounds controversial, but if you can strengthen rat’s bones maybe there is potential.”

Naturally, bone marrow is needed in order to produce new blood cells, but Vignery says that removing it from a damaged bone won’t affect a person’s health, provided marrow is kept in other bones. Levy says further animal tests are needed, but is hopeful that before the end of this year, they will test the technique on humans.

Sources and further reading

Article based on report from NewScientist, 5 April, by Colin Barras.
* MedlinePlus
** Study held at Yale University, led by Agnès Vignery.
*** Warren Levy of Unigene Laboratories, in Fairfield, New Jersey, which provided Vignery’s team with PTH
**** Peter Kay of the University of Manchester, UK [/quote]