New Bone Created in Minimally Invasive Procedure

A new technique that combines bone marrow removal and injection of a hormone could help promote rapid formation of new bone at targeted locations in the body, reports a new study.

Researchers at Yale School of Medicine (New Haven, CT, USA) subjected the left femur of rats to mechanical marrow ablation, or sham operation, and injected the animals daily with parathyroid hormone (PTH) or vehicle for 1, 2, or 3 weeks in a first experiment, then with PTH, parathyroid hormone-related peptide (PTHrP), or vehicle for 3 weeks in a second experiment. They then subjected both femurs from each rat to soft X-ray, peripheral quantitative computed tomography, computed tomography on a microscale, and histological analysis, and determined the concentration of serum osteocalcin. In addition, in the second experiment, the researchers determined the serum concentration of calcium, tartrate-resistant acid phosphatase (TRAP), and receptor activator of NF-¦ÊB ligand (RANKL) at 3 weeks, and subjected femurs to biomechanical testing.

The researchers found that the procedure created new bone tissue that appeared structurally and biologically normal. PTH increased trabecular density in the right femur, but failed to induce bone formation in the medullary region of the right unoperated femoral shafts. The newly formed bone endowed left femoral shafts with improved biomechanical properties when compared to those of right femurs and left femurs from control, sham-operated, and vehicle-treated rats. PTHrP, like PTH, increased serum osteocalcin, but neither hormones increased serum calcium, TRAP, or RANKL at 3 weeks. The study was published in the February 2008 issue of Tissue Engineering.

¡°This could radically change the way patients are currently treated for weakened or fractured hips, vertebrae, and acute traumatic long bone fractures,¡± said senior author Agn¨¨s Vignery, D.D.S., Ph.D., an associate professor of orthopedics. ¡°The ideal approach would be to create new bone where it is needed and at a faster rate.¡±

The study was done in collaboration with Unigene Laboratories (Fairfield, NJ, USA) and additional studies are underway that extend the results of this work in other animals and that will determine whether the newly formed bone can be preserved over a long period of time.


Related Links:
Yale School of Medicine
Unigene Laboratories