Platelets and white blood cells from peripheral blood are essential to healing and the body naturally aggregates platelets and white cells efficiently to sites of trauma. With age, your body does not lose its ability to aggregate platelets from blood to the area of a defect. Vasculogenesis (i.e. the ability of your body to mobilize stem cells from the marrow space to the site of trauma) does diminish significantly with age because of fewer stem cells in the body and a diminished ability to travel to sites of a defect. With age, marrow mediated healing diminishes dramatically.
Transplanting marrow exactly at the site of injury mimics and supplements your body’s critical response to healing, a response that diminishes with age.
Lommatzsch M, et al. The impact of age, weight and gender on BDNF levels in human platelets and plasma. Neurobiol Aging. 2005 Jan;26(1):115-23.
Heiss C, et al. Impaired progenitor cell activity in age-related endothelial dysfunction. J Am Coll Cardiol. 2005 May 3;45(9):1441-8.
Scheubel RJ, et al. Age-dependent depression in circulating endothelial progenitor cells in patients undergoing coronary artery bypass grafting. J Am Coll Cardiol. 2003 Dec 17;42(12):2073-80.