Aging effect on inductive capacity of human demineralized bone matrix

Abstract

Demineralized bone powder (DBP) prepared from human cortical bone was implanted into subcutaneous pouches of athymic Nu/Nu mice for 28 days. The osteoinductive capacity was evaluated by histomorphometry of the induced cartilage and bone, and by alkaline phosphatase activity in the implant. Very small amounts of new bone and cartilage were found at histological analysis, confirming that human DBP is much less osteoinductive than that from other species. Whereas the morphometric data of the implants from the young and aged donors were not significantly different, the alkaline phosphatase activity was significantly lower in the implants from the old donors than from the younger ones. This difference between the morphometric and biochemical results could reflect the fact that the enzymatic activity is already present in the osteoprogenitor cells. At 28 days, the osteoblastic activity in contact with DBP from the aged group is characterized by a decrease in the enzymatic amount which is not yet visible at the tissue level. This tendency to a decrease in the osteoinductive capacity of bone matrix is an additional aspect of the age-related alterations which occur in bone tissue and could be attributed to modifications of different proteins of the bone matrix, including bone morphogenetic protein.

Osteoinductivity of Demineralized Bone Matrix Is Independent of Donor Bisphosphonate Use

“…No young donors were used in the present study; therefore, it is not known if there would have been a higher percent of the samples with osteoinductive properties in demineralized bone matrix processed from a young donor population. Our results support previous observations from our group 34 and others [52][53][54] , showing that donors who are sixty to seventy years of age continue to possess osteoinductive bone, and suggest that any loss of osteoinductivity occurs later in life.…”

The efficacy of rhBMP-2 versus autograft for posterolateral lumbar spine fusion in elderly patients

“…It was thus proposed that rhBMP-2 could lead to bone and fusion formation by inducing the differentiation of osteocytes in elderly patients. However, our results indicate that rhBMP-2, like autograft, has limitations in overcoming the possible physiological changes associated with aging, such as decreased bone metabolism, collagen synthetic activity and alkaline phosphatase synthesis [23], and decreased differentiating capacity of aging osteoprogenitor cells [24,25].…”

Three-Years Outcome of Microdiscectomy via Paramedian Approach for Lumbar Foraminal or Extraforaminal Disc Herniations in Elderly Patients over 65 Years Old

“…In addition to short-term medical or surgical complications, long-term postoperative problems associated with the spine itself are also important. The risk of adjacent segment disease is associated with age, because of decreased ability for biochemical responses to changes after spinal fusion with age2328). Moreover, bone quality, which affects screw stability and bone fusion, is also directly associated with age.…”