The role of autogeneic bone marrow in the repair of a skull trephine defect filled with hydroxyapatite granules in the rabbit.

For study of the effect of autogeneic bone marrow on the repair of skull defects filled with hydroxyapatite (HA) granules, 20 trephine defects 11 mm in diameter in 10 New Zealand rabbit skulls were made. Three defects were implanted with HA granules (HAg), and seven defects were implanted with HA granules mixed with autogeneic bone marrow (HAg/BM) from the femoral medullary canal. Autogeneic bone marrow (BM) was implanted in three defects, and seven defects were left unfilled. Histomorphometric quantitation of bone and connective-tissue ingrowth into defects showed that the area of new bone ingrowth in BM (70.3 +/- 8.4%) was significantly larger than that in HAg (34.4 +/- 3.9%) and in HAg/BM (24.0 +/- 5.1%) (P < 0.01 and P < 0.01, respectively). Immunohistologic staining detected fibronectin and collagen type III as the main components in the defects filled with HAg and HAg/BM. The osteoconductive capacity of HA granules was not stimulated by adding fresh autogeneic bone-marrow cells.